JP5855291B1 - Heat exchanger for power generation system, binary power generation system including the heat exchanger, and control method for heat exchanger for power generation system - Google Patents

Abstract

A highly efficient and low-cost heat exchanger and a power generation system using the heat exchanger are provided. A heat exchanger according to the present invention includes a first flow path through which a first fluid can flow and a second flow path through which a second fluid that exchanges heat with the first fluid flows. An electrolytic cell in which at least a part of the first flow path and the second flow path is partitioned by an anode plate and a cathode plate to which a predetermined potential is applied from a power source, and the anode plate and the And a control unit that applies the predetermined potential to the cathode plate and performs control to reverse the polarity of the anode plate and the cathode plate after the potential is applied. [Selection] Figure 1

Description

  The present invention relates to a heat exchanger, a binary power generation system using the heat exchanger, and a control method for the heat exchanger.

Due to the global protection of the global environment, power generation using industrial waste heat generated from the production process of geothermal and industrial products is gaining attention because of its extremely low carbon dioxide emissions.
Among these, the following two methods exist in the geothermal power generation method. That is, the first method uses a gas-liquid two-phase thermal fluid pressurized and heated in the deep underground, and the geothermal steam when this thermal fluid is ejected to the ground through a well is guided to the turbine. This is a flash cycle system that generates electricity. In the second method, the thermal fluid is once guided to the heat exchanger, the heat exchanger exchanges heat with the working fluid, and the steam of the working fluid heated by the thermal fluid is guided to the turbine for power generation. This is a binary cycle method.

In the power generation using the binary cycle method, in recent years, a binary power generation system using geothermal water such as hot spring water as an example of a thermal fluid has been developed.
Geothermal water often exists at a relatively shallow depth even underground, and has the advantage that the introduction cost and risk of a power generation system are not high compared to conventional geothermal power generation. Since geothermal water usually has a temperature of 100 ° C. or less, a low boiling point medium such as alternative chlorofluorocarbon (HFE), pentane (C ₅ H ₁₂ ) or ammonia is used as a working fluid. It is used.

In this binary power generation system, geothermal water is introduced into a heat exchanger provided on the ground, and heat is exchanged with a low boiling point medium separately introduced into the heat exchanger to generate low boiling point medium vapor. The steam of the low boiling point medium is introduced into the steam turbine to rotate the turbine, and power is generated by the generator using this rotation.
The low-boiling medium steam discharged from the steam turbine is cooled and liquefied in the condenser, then sent again to the heat exchanger, heated by geothermal water, and introduced into the steam turbine as low-boiling medium steam. Is repeated.

As for the above-described binary power generation system, there has been proposed a technique focused on enhancing the energy use efficiency of the thermal fluid as exemplified in Patent Document 1 below.
For example, according to this Patent Document 1, by changing the evaporation temperature of a thermal fluid, changing the combination of an evaporator and a preheater, or using a mixed liquid of ammonia and water as a working fluid, Increasing efficiency is disclosed (for example, see Patent Document 1).

JP-A-11-350920

  However, when geothermal water is used, it is assumed that the following problems occur. That is, the hot spring water contains components such as minerals such as calcium and sulfur, and is deposited on the inner wall of the piping and inside the heat exchanger in the circulation system including the heat exchanger. If this deposit adheres to the surface of the heat exchanger, for example, the heat exchange efficiency between the thermal fluid (geothermal water) and the working fluid (pentane, etc.) is significantly reduced. There is also a risk of failure.

On the other hand, if the heat exchangers and piping are regularly cleaned by human naval tactics, clogging of piping and failure of the heat exchanger will be reduced, but the benefits of binary power generation will be lost due to the increase in costs. It must be avoided.
In addition, it is conceivable to introduce a chemical into a heat exchanger or piping for cleaning, but in recent years, the use of such a chemical has been restrained from the viewpoint of preventing environmental pollution.
Note that this problem can occur not only in the thermal fluid containing impurities but also in the inflowing liquid flowing into the heat exchanger or the like, and how to reduce the energy transfer efficiency between the fluids while reducing the cost will be discussed in the future. It becomes important.

  In view of the above problems, the present invention provides a purification system such as a heat exchanger that can maintain high-efficiency power generation at low cost even when an inflowing liquid containing impurities is used. With the goal.

In order to solve the above-described problem, a heat exchanger for a power generation system according to an embodiment of the present invention is configured to perform heat exchange between a first flow path through which a first fluid can flow and the first fluid. An electrolytic cell having a second flow path through which two fluids circulate, wherein at least a part of the first flow path and the second flow path is partitioned by an anode plate and a cathode plate to which a predetermined potential is applied from a power source; Then, after applying the predetermined potential by starting energization to the anode plate and the cathode plate, applying a potential whose polarity is reversed with respect to the predetermined potential, and then performing a cleaning process for releasing the energization, look including a control unit that performs control to repeat a predetermined cycle, the control unit, rather than period in which the potential which the predetermined potential and the polarity is inverted, starts again energized after releasing the energization The period until the predetermined potential is applied is longer To, and performs the control for imparting respective potential to the cathode plate and the anode plate.

In the heat exchanger described above, it is preferable that a plurality of anode plates and cathode plates are alternately arranged in the electrolytic cell so as to face each other.
In order to solve the above-described problem, a binary power generation system according to an embodiment of the present invention includes the above-described heat exchanger and a control device that controls the power supply, and the control device has a predetermined timing. The polarity of the anode plate and the cathode plate is reversed.

The binary power generation system described above preferably includes an ammeter that measures a current flowing between the anode plate and the cathode plate, and the control device reverses the polarity based on a measured value of the ammeter.
Each of the binary power generation systems described above preferably includes a pressure gauge that measures the pressure of the vapor generated from the second fluid, and the control device preferably reverses the polarity based on a measurement value of the pressure gauge.
A thermometer for detecting the temperature of the first liquid flowing into the electrolyzer and the temperature of the first liquid flowing out of the electrolyzer; and the control device is based on a measured value of the thermometer. It is preferable to reverse the polarity.

Further, in each of the binary power generation systems described above, the first steam turbine driven by the medium steam generated by evaporation of the second fluid, the first steam turbine, the anode plate, and the cathode plate are electrically connected. It is preferable that the control device uses at least a part of the power generated by the first steam turbine as the power source.
In the above binary power generation system, the first steam is decompressed and separated into steam and hot water, and the second steam driven by the steam separated by the decompressed gas-liquid separator. And a turbine.

Further, in each of the binary power generation systems described above, after being connected to the heat exchanger or the first pipe through which the first fluid passed through the heat exchanger flows, the polarity of the anode plate and the cathode plate is reversed. It is preferable to further include a discharge pipe through which the first fluid can flow.
The binary power generation system includes a valve that switches between the discharge pipe and the first pipe, and the control device switches the valve when reversing the polarity of the anode plate and the cathode plate to switch the heat. It is preferable to perform control to cause the thermal fluid introduced into the exchanger to flow into the discharge pipe.

In each of the binary power generation systems described above, hot spring water containing a mineral content or a sulfur content can be applied as the first fluid.
Moreover, in order to solve the said subject, the control method of the heat exchanger for power generation systems concerning one Embodiment of this invention is the heat exchanger with which the anode plate and cathode plate which a predetermined electric potential is provided from a power supply are arrange | positioned The first fluid is circulated through the first pipe so as to be in contact with the cathode plate, and the first fluid and the heat are isolated from the first fluid in the heat exchanger. The second fluid to be exchanged is circulated through the second pipe into the heat exchanger, energization is started to the anode plate and the cathode plate, and the predetermined potential is applied. grant potential polarity is inverted potential, followed by a cleaning process for releasing the energization look-containing and a repeating at predetermined intervals, to impart a potential said predetermined potential and said polarity is reversed More than the period, after turning off the energization, start energizing again Serial As better time to impart a predetermined potential is increased, the potentials relative to the cathode plate and the anode plate is characterized in that it is applied.

  According to the present invention, it is possible to remove components (such as minerals such as calcium ions and magnesium ions) that are included in the first liquid as the inflowing liquid flowing into the power generation system or the like and cause a reduction in capacity. Thus, for example, heat exchange processing or the like can be executed while suppressing a decrease in power generation capacity. Furthermore, such electrolytic treatment can prevent contamination of the piping or the like through which the first liquid flows without using a chemical solution with a large environmental load, and can realize a low-cost and high-efficiency system.

FIG. 1 is an overall configuration diagram of a binary power generation system BES1 according to the first embodiment of the present invention. FIG. 2 is a configuration diagram of a heat exchanger according to an embodiment of the present invention. FIG. 3a is a view for explaining the purification action of the heat exchanger according to one embodiment of the present invention. FIG. 3b is a diagram showing the relationship between the specific cleaning process time and the reversal process in each electrode. FIG. 4 is an overall configuration diagram of a binary power generation system BES2 according to the second embodiment of the present invention. FIG. 5 is an overall configuration diagram of a binary power generation system BES3 according to the third embodiment of the present invention. FIG. 6a is an overall configuration diagram of a binary power generation system BES4 according to the fourth embodiment of the present invention. FIG. 6B is a configuration diagram relating to the cleaning device 101 of the binary power generation system BES4. FIG. 7 is an overall configuration diagram of a binary power generation system BES5 according to the fifth embodiment of the present invention. FIG. 8 is a diagram for explaining a first modification of the binary power generation system according to the present invention. FIG. 9 is a diagram for explaining a second modification of the binary power generation system according to the present invention. FIG. 10 is a diagram for explaining a third modification of the binary power generation system according to the present invention. FIG. 11 is a diagram for explaining a fourth modification of the binary power generation system according to the present invention. 12A is a perspective view of a flat electrode plate applicable to the present invention, FIG. 12B is a perspective view of a wavefront electrode plate having a meandering curved surface, and FIG. It is a perspective view of the uneven | corrugated electrode plate with which a recessed part and a convex part continue in a row.

  Hereinafter, an embodiment for carrying out the present invention will be described taking a binary power generation system as an example. For convenience of explanation, the X direction, the Y direction, and the Z direction are respectively defined as appropriate in the following explanation, but it goes without saying that the scope of rights of the present invention is not reduced.

<< First Embodiment >>
FIG. 1A is an overall configuration diagram of a binary power generation system 1A according to the first embodiment of the present invention.
The binary power generation system BES1 of the present embodiment includes a first pipe L ₁ , a heat exchanger (evaporator) 1, a second pipe L ₂ , a steam turbine 2, a generator 3, a condenser 4, and an overall control device 5. It consists of In addition, you may refer suitably for well-known geothermal power generation systems, such as Unexamined-Japanese-Patent No. 2013-170553, except the structure explained in full detail below.

First pipe L ₁ is thermal fluid source and the heat exchanger 1 existing underground, even at a pipe connecting such a heat exchanger 1 and rivers. This first pipe L _1, via a pump (not shown), reducing the thermal fluid source with circulating pumping up the thermal fluid to the heat exchanger 1, the heat exchange thermal fluid in the heat exchanger 1 to the rivers (Drain). In addition, you may reuse the thermal fluid heat-exchanged with the heat exchanger 1 again as a thermal fluid, without draining.

As will be described later in the embodiments, the “first fluid” to which the present invention can be applied is not limited to a thermal fluid, but first, a thermal fluid will be described as an example. Although various applications are possible as this thermal fluid, in this embodiment, for example, hot spring water of about 50 ° C. to 150 ° C. is used as the thermal fluid. In addition to the hot spring water, the thermal fluid applicable in the present embodiment includes, for example, industrial waste water (waste hot water generated in the process of industrial production such as hot water washing) and high-pressure groundwater used in conventional geothermal power generation. (These are collectively referred to as “hot water” as appropriate).
The heat exchanger 1, the electrolytic cell 11 is configured to include an electrode plate 12 and the control unit 13, the heat exchange with the working fluid first through the pipe L ₁ will be described later with hot fluid pumped up from the thermal fluid source I do.

  FIG. 2 shows a configuration diagram of the heat exchanger 1. The electrolytic cell 11 is an electrolytic cell for exchanging heat between the working fluid and the thermal fluid while electrolytically treating the thermal fluid, and a plurality of (four) electrode plates 12 face each other with a predetermined distance therebetween. Be placed. A predetermined potential is applied to the electrode plate 12 disposed in the electrolytic cell 11 from a power source (not shown) via wirings (e1, e2). As the power source, a known device can be used. For example, a DC voltage of, for example, 50 V or less can be applied between the electrode plates 12 as a predetermined potential.

An insulator for keeping the distance between the electrodes constant may be disposed between the electrode plates 12 as necessary.
In addition, the number of the cathode plates and the anode plates that are alternately arranged is not limited to an example in which a total of four cathode plates and two anode plates are arranged. For example, three or more each may be alternately arranged, or each may be arranged one by one. Good. Further, it is not necessary to arrange the same number of cathode plates and anode plates. For example, the number of cathode plates may be greater than that of the anode plates and alternately arranged.

In the electrolytic cell 11, a flow path through which a thermal fluid or a working fluid flows is formed by the wall surface of the electrolytic cell 11 and the electrode plate 12. In FIG. 2, the second flow path R <b> 2 through which the working fluid circulates by the wall surface of the electrolytic cell 11 and the cathode plate 12 ₁ , the anode plate 12 ₂ and the cathode plate 12 ₃ , and the anode plate 12 ₄ and the wall surface of the electrolytic cell 11. Is formed. The cathode plate 12 ₁ and the anode plate _{12 2,} the cathode plate 12 ₃ and the anode plate 12 _4, the first flow path R1 which thermal fluid respectively flows are formed. Thus, at least a part of the flow path through which the thermal fluid or the working fluid flows is partitioned in the electrolytic cell 11 by the electrode plate 12 (anode plate and cathode plate) to which a predetermined potential is applied from the power source.

As a result, the thermal fluid and the working fluid are isolated from each other and circulate in the heat exchanger 1.
In FIG. 2, the directions of the fluids flowing through the first channel R1 and the second channel R2 are opposite to each other, but the directions of the fluids flowing through the first channel R1 and the second channel R2 are different. The same direction may be used. Further, a known sealing material may be interposed at the boundary between the wall surface of the electrolytic cell 11 and the electrode plate 12 to prevent fluid leakage between adjacent flow paths. In this case, the sealing material is preferably an insulating resin.
The control unit 13 performs control for applying a predetermined potential to the electrode plate 12 from a commercial power source (not shown) during the heat exchange process, and also cleans the surface of the cathode plates (the cathode plate 12 ₁ and the cathode plate 12 _{3 in} FIG. 2). (Described later).

The second pipe L ₂ is a pipe through which a working fluid as an example of a “second fluid” flows. In this embodiment, the working fluid circulates in the heat exchanger 1, the steam turbine 2, and the condenser 4. Used for. That is, the working fluid circulates between these devices as a closed loop. The working fluid is not particularly limited except that a fluid having a boiling point lower than that of the thermal fluid is used, and various fluids such as butane (C ₄ H ₁₀ ) and alternative chlorofluorocarbon (HFE) are applicable. In the present embodiment, pentane (C ₅ H ₁₂ ) having a boiling point of about 36 ° C. is used as the working fluid.
Pentane as the working fluid is evaporated by receiving heat transfer from hot spring water in the heat exchanger 1 (vaporized) and is converted into the operating gas is introduced into the steam turbine 2 through the second pipe L _2.

The steam turbine 2, the second through the pipe L ₂ is connected to the heat exchanger 1 and the steam turbine 2, the work from the heat exchanger 1 with pentane second vapor state, which is introduced through a pipe L ₂ I do.
The generator 3 is connected to the steam turbine and generates power according to the work of the steam turbine 2. The electric power generated by the generator 3 is supplied to, for example, a substation or a house of an electric power company through a transformer (not shown).
Condenser 4 is connected to the steam turbine 2 and the heat exchanger 1 through the second pipe L _2. In the condenser 4, the pentane in a vapor state that has passed through the steam turbine 2 is condensed using water or air (heat exchange is performed) and converted into liquid pentane. The pentane converted liquid is reintroduced into the heat exchanger 1 via a second pipe L ₂ and a pump (not shown) as the working fluid.

<Deposition in the heat exchanger 1>
In binary power generation system BES of the present embodiment, hot water is flowing through the portion of the first and in the heat exchanger 1 pipe L ₁ as the heat fluid.
For example, when hot water is hot spring water, components such as minerals such as magnesium, potassium, sodium, calcium, and sulfur are usually included.

For example, in the case of a bicarbonate spring containing a large amount of calcium, when various conditions such as temperature and pH change, a part of the dissolved components in the hot spring water is converted into solids (C _a CO ₃ ) and it turned to be deposited on the first pipe L ₁ and the heat exchanger 1.

Ca ²⁺ + 2HCO ^{3 −} → CaCO ₃ ↓ + H ₂ O + CO ₂ ↑ (1)

Therefore, in this embodiment, even when performing geothermal power generation using hot spring water as a thermal fluid for a long time, the heat exchanger 1 is provided with a function capable of suppressing a decrease in heat exchange efficiency due to the precipitates described above.

<Purification treatment during heat exchange>
That is, in this embodiment, as shown in FIGS. 3A and 3B, the control unit 13 of the heat exchanger 1 performs an inversion process of inverting the polarity of the anode plate and the cathode plate at a predetermined timing.
More specifically, as shown in FIG. 3A, when the polarity of the anode plate and the cathode plate is reversed by the control unit 13, deposits (calcium, etc.) adhering to the cathode plate are dissolved in the washing water. put out. At this time, calcium and other components begin to adhere to the electrode plate that has become the cathode plate, but cleaning is performed more than the amount of deposits attached to the cathode plate by devising a cleaning process including reversal processing. The amount of deposits that dissolve in water can be increased, and the electrode plate is purified when viewed in total.

During this reversal process, the control unit 13 switches the supply system from the spring water to the wash water using the valve Vb such the installed three-way valve to the first pipe L _1, supplies the washing water to the heat exchanger 1 Control may be performed. Moreover, the wash water used for washing | cleaning may be drained in a river etc. via the discharge pipe separately connected to the heat exchanger 1, and may be supplied to a hot spring facility. After supplying a predetermined period only wash water may be performed to resume controlling the generator Replace the valve Vb three-way valve or the like provided in the heat exchanger 1 first pipe L ₁ of about.

Since the washing water used for washing contains a high concentration of minerals and basically no harmful substances are added, it may be used as commercial hot spring water or used as drinking water. In addition, although there is no limitation in particular as washing water, in this embodiment, water, such as a tap water, is used, for example. The discharge pipe for discharging wash water is can be omitted, this may be used as the first pipe L ₁ connecting a heat exchanger 1 and river described above when.

Further, as the predetermined timing, any timing such as every hour, every day, every week, every month or every six months may be set, and the supply flow rate or flow rate of hot spring water to the heat exchanger 1 may be set. It is preferable to consider the above. For example in passing in the first pipe L ₁ the spring water at a speed of about 1 m / s, 0.1 mm thick precipitate was observed in approximately 30 minutes.
Further, the cleaning water supply period may be determined according to a predetermined timing, and when the inversion process is long for a long time, it is preferable that the cleaning water supply period is also long.

As an example, FIG. 3B shows a specific relationship between the cleaning process time and the reversal process in each electrode. Also shows an energized state in FIG. 3 (b) in example cathode plate 12 _1.
As shown, in this embodiment not been made always energized in the cathode plate, the cleaning power reduction from the viewpoint of cleaning efficiency for each predetermined period T ₁ is performed. The period T ₁ is not particularly limited as described above, but in this example, the period T ₁ is described as being every 3 hours, for example. In the cleaning process once in this example, applied to the period T ₂ by + voltage cathode plate 12 ₁ is first, followed by the period T ₃ in the polarity is reversed - voltage is applied to the cathode plate 12 _1.
In the present embodiment, the period T ₂ and the period T ₃ are set to the same 30 seconds, but the length is not particularly limited, and may be a time other than 30 seconds, or different times may be used for the period T ₂ and the period T _3. It may be set. Although immediately period T ₃ after a period T ₂ has been started, there may be a period in which a voltage is not applied between the period T ₂ and time T ₃ is not limited thereto.

  According to this embodiment, by controlling the potential applied to the electrode plate 12 of the heat exchanger 1 and executing a desired electrolytic treatment, the amount deposited from the hot spring water on the electrode plate surface, the washing water from the electrode plate surface It is possible to control the amount of precipitates dissolved in the solution and the timing at which these occur. Moreover, the above-described precipitate can be purified with inexpensive washing water without using a special chemical. Therefore, a binary power generation system using hot spring water can be realized at low cost and high efficiency.

<< Second Embodiment >>
FIG. 4 is an overall configuration diagram of a binary power generation system BES2 according to the second embodiment of the present invention. Since the binary power generation system BES2 is mainly different from the binary power generation system BES1 of the first embodiment in the configuration of the generator 3 and the heat exchanger 1, only the differences will be described below, and the same configuration and the same as the binary power generation system BES1. Elements having functions are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  As shown in FIG. 4, the binary power generation system BES2 of the second embodiment guides a part of the power generated by the generator 3 to the heat exchanger 1 via the wiring e3. More specifically, the control unit 13 of the heat exchanger 1 performs control for receiving a part of the electric power generated by the generator 3 and applying the potential to the electrode plate 12 (cathode plate and anode plate).

  According to the present embodiment, since the electric power generated by the generator 3 is used without preparing a special power source for applying a potential to the electrode plate 12 of the heat exchanger 1, not only the apparatus system can be simplified but also the apparatus cost. And energy costs can be reduced.

«Third embodiment»
FIG. 5 is an overall configuration diagram of a binary power generation system BES3 according to the third embodiment of the present invention. Compared to the binary power generation system BES1 of the first embodiment and the binary power generation system BES2 of the second embodiment, the binary power generation system BES3 is a decompressed gas-liquid separator 6, a steam control valve 7, a second steam turbine 8 and a second power generation. Since the configuration of the machine 9 is mainly different, only the differences will be described below, and elements having the same configuration and function as those of the binary power generation systems described above will be denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 5, the binary power generation system BES3 of the third embodiment is a power generation system in which a so-called flash type geothermal power generation system and a binary power generation system are combined.
More specifically, the third pipe L ₃ for pumping thermal fluid as the first fluid is connected to a vacuum gas-liquid separator 6, the heat exchanger via a further first pipe to the vacuum gas-liquid separator 6 1, steam control valve 7 is connected via a fourth pipe L _4. Among these, the steam control valve 7 is connected to the second steam turbine 8 through the fourth pipe L ₄ .

The second steam turbine 7 is connected to the fourth pipe L ₄ as a second generator 9, and the discharge pipe. In this embodiment, high-pressure groundwater existing in a relatively deep underground is used as the thermal fluid.
First third high pressure groundwater through a pipe L ₃ is supplied to the vacuum vapor-liquid separator 6, where it is reduced in pressure and separated into a high-pressure steam and high-pressure heat water. The high-pressure steam separated by the decompression gas-liquid separator 6 is sent to the second steam turbine 8 through the steam control valve 7 to perform work, whereby desired power is generated by the second generator 9. The low-pressure steam after working in the second steam turbine 8 is reduced (discharged) to a river or the like via a pipe or the like.

On the other hand, high-pressure hot water separated in the vacuum vapor-liquid separator 6, since the first through the pipe L ₁ is sent to the heat exchanger 1, binary power generation described in the above embodiment is performed.
Desired electric power is generated by the second generator 9 by being sent to the second steam turbine 8 through the steam control valve 7 and performing work. Part of the electric power generated by the generator 3 is guided to the heat exchanger 1 via the wiring e3. More specifically, the control unit 13 of the heat exchanger 1 performs control for receiving a part of the electric power generated by the generator 3 and applying the potential to the electrode plate 12 (cathode plate and anode plate).

In the high-pressure groundwater used in this embodiment, a part of the magma component existing underground may be present as ions, and the rare metal contained in the magma is deposited on the surface of the electrode 12 of the heat exchanger 1 described above. Is also possible.
Therefore, if non-ferrous metal such as rare metal deposits on the surface of the electrode 12 of the heat exchanger 1, the cathode plate to which the non-ferrous metal (rare metal) is attached is exchanged without being discharged into the river using the washing water and collected. The rare metal may be used for industrial purposes.

  According to this embodiment, since the clogging of the heat exchanger 1 and the piping can be suppressed without using a special chemical for cleaning, a decrease in heat exchange efficiency can be suppressed. Furthermore, since power generation using two-stage heat exchange is performed, relatively large power can be generated. In some cases, valuable non-ferrous metals such as rare metals can also be collected.

<< Fourth Embodiment >>
FIG. 6A is a diagram showing a binary power generation system BES4 according to the fourth embodiment of the present invention. The binary power generation system BES4 differs from the binary power generation systems described above in that the cleaning device is incorporated in the binary power generation system as a separate body, not as the heat exchanger 1. That is, in each of the above embodiments, the heat exchanger 1 has a purification function, but in this embodiment, the heat exchanger and the purification device are configured separately and connected to each other.
Therefore, only differences will be described below, and elements having the same configuration and functions as those of the binary power generation system described above are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted. Note that the system in which the cleaning device of this embodiment is incorporated may be a power generation system other than the binary power generation system, or may be another known system using a fluid other than the power generation system.

As shown in FIG. 6A, the binary power generation system BES4 of the present embodiment includes a heat exchanger 100 and a cleaning device 101. The out heat exchanger 100, geothermal water sucked up from the first fluid for example groundwater is introduced through the first pipe L ₁ and the cleaning device 101. In other words, the cleaning device 101 is interposed between the thermal water source and a heat exchanger 100 which is connected to the first via a pipe L _1, a first fluid (in this example that has been cleaned by the cleaning device 101 Then, geothermal water) flows into the heat exchanger 100.

FIG. 6B shows a detailed configuration of the cleaning apparatus 101 of this embodiment.
In the cleaning apparatus 101, an electrode plate 12a and an electrode plate 12b are respectively disposed in a container 102 as an electrolytic cell, and at least a part of a flow path through which geothermal water flows through the electrode plate 12a and the electrode plate 12b. Is formed. Among these, in the initial state, for example, the electrode plate 12a functions as an anode and the electrode plate 12b functions as a cathode. Then, after a predetermined time has elapsed since the system operation, the cleaning process (such as the electrode polarity reversal operation) described in the first embodiment is performed. In the cleaning process, the geothermal water may be discharged out of the system via the valve Vb without sending the geothermal water to the heat exchanger 100. In addition, tap water other than geothermal water may be used as cleaning water during the cleaning process. Further, in the present embodiment, two electrode plates 12 are used, but it goes without saying that electrode plates 12 other than two such as four may be used as in the above-described embodiments.

«Fifth embodiment»
FIG. 7 is a diagram showing a binary power generation system BES5 according to the fifth embodiment of the present invention. The binary power generation system BES5 is mainly different from the binary power generation systems described above in that the heat exchanger has a two-stage configuration of a primary heat exchanger 200 and a secondary heat exchanger 201.
Therefore, only differences will be described below, and elements having the same configuration and function as the binary power generation system described above are denoted by the same reference numerals as in the first embodiment, and description thereof will be omitted as appropriate. Note that the binary power generation system including the secondary heat exchanger 201 of the present embodiment may be a known binary power generation system as it is, or may be a known system other than the binary.

As shown in FIG. 7, the power generation system of the present embodiment further includes a primary heat exchanger 200 in addition to the binary power generation system BES5 including the secondary heat exchanger 201. Of these, between the secondary heat exchanger 201 and the primary heat exchanger 200, an intermediate fluid through the sixth pipe L ₆ (e.g., pure water) it has a structure to circulate. Since the sixth pipe L ₆ has a closed loop structure, foreign matter from the outside it is unlikely to be mixed.
Further, the secondary switch 201 the second fluid (e.g., pentane, etc.) are flowed described above through a second pipe L _2, an intermediate fluid (pure water) and a second fluid flowing the sixth pipe L ₆ (pentane ) And heat exchange.

On the other hand, as the structure of the primary heat exchanger 200, for example, the structure of the heat exchanger 11 described in FIG. 2 can be applied. For example, as shown in FIG. 2, while the first pipe _{L 1} from the flow path R1 through the first fluid (such as geothermal water), flow that is partitioned from the flow path R1 in the electrode ₁₂ 1 to 12 ₄ the road R2 sixth (such as pure water) intermediate fluid through a pipe L ₆ may adopt a flow configuration. Thus, within the 200 primary heat exchanger, the first fluid flowing through the first pipe L ₁ (such as geothermal water), and an intermediate fluid that has flowed through the sixth pipe L ₆ (pure water) Heat exchange between the two.

The intermediate fluid to be circulated in the sixth pipe L6 is not limited to pure water, and any other known liquid or gas may be used as long as the fluid has at least a boiling point higher than the second fluid and lower than the first fluid. .
Further, the cleaning process using the electrodes 12 _{1 to} 12 ₄ is the same as the cleaning process described above, and thus the description thereof is omitted.
Further, in the present embodiment, the binary power generation system BES5 and the primary heat exchanger 200 have been described as separate bodies. However, it is needless to say that the primary heat exchanger 200 may be referred to as a binary power generation system BES5.
According to the present embodiment, the first fluid that may be precipitated does not circulate in the binary power generation system BES5, and the fluid (pure water and pentane in the present embodiment) that circulates in the binary power generation system BES5 is always clean. The state is maintained. Therefore, since only the relatively small primary heat exchanger 200 needs to be cleaned, a power generation system with excellent maintainability can be realized.

Each of the above-described embodiments can be variously modified without departing from the spirit of the present invention. Hereinafter, modifications that can be appropriately applied to each embodiment will be described. In the following modifications, the same reference numerals are assigned to the same functions and operations as those described above, and the description thereof will be omitted as appropriate.
<< Modification 1 >>
FIG. 8 is a diagram for explaining the first modification, and includes an ammeter I for measuring the current flowing through the electrode 12 in the heat exchanger 1. In the first modification, an ammeter I is installed on the wiring between the heat exchanger 1 and the control unit 13.
The overall control device 5 monitors the current value measured by the ammeter I, and controls the polarity inversion operation of the electrode plate 12 via the control unit 13 of the heat exchanger 1 based on the detected current value. .

For example, when the measured value (current value) measured by the ammeter I falls below a predetermined threshold, the overall control device 5 performs control to reverse the polarity of the electrode plate 12. At this time, the overall control unit 5 may also execute control for stopping the circulation of the working fluid and performing the above-described cleaning process.
In addition, although the ammeter was used in this modification 1, you may perform control which measures the voltage value between a cathode plate and an anode plate, and reverses the polarity of the electrode plate 12 based on this voltage value.

<< Modification 2 >>
FIG. 9 is a diagram for explaining the second modification, and includes a pressure gauge P for measuring the pressure of the steam of the working fluid sent from the heat exchanger 1 to the steam turbine 2. In the second modification, a pressure gauge P is installed on a pipe between the heat exchanger 1 and the steam turbine 2.
The overall control device 5 monitors the pressure value measured by the pressure gauge P, and controls the polarity reversal operation of the electrode plate 12 via the control unit 13 of the heat exchanger 1 based on the detected pressure value. .

  For example, when the measured value (pressure value) measured by the pressure gauge P falls below a predetermined threshold value (for example, a value based on the pressure value when flowing from the condenser 4 into the heat exchanger 1), the overall control device 5 performs control to reverse the polarity of the electrode plate 12. At this time, the overall control unit 5 may also execute control for stopping the circulation of the working fluid and performing the above-described cleaning process.

<< Modification 3 >>
FIG. 10 is a diagram for explaining the third modification. In the third modification, the temperature of the first fluid (for example, hot water) flowing into the heat exchanger 1 and the temperature of the first fluid (hot water) flowing out from the heat exchanger 1 are detected using the thermometer TG. . The overall control device 5 monitors the pressure value measured by the thermometer TG, compares the detected temperatures, and when the difference between the two becomes a predetermined value or less, the control unit of the heat exchanger 1 The polarity inversion operation of the electrode plate 12 is controlled via 13.

More specifically, a thermometer TG is disposed on a first pipe L ₁ before and after the heat exchanger 1 as shown in FIG. 10, the temperature of the thermometer TG and the downstream side of the upstream from the heat exchanger 1 The temperature with the total TG is compared.
For example, when the temperature detected on the downstream side is not so much lower than the temperature detected on the upstream side, it is estimated that the heat exchange efficiency of the heat exchanger 1 is lowered. Therefore, the overall control device 5 controls the electrode plate 12 via the control unit 13 of the heat exchanger 1 according to the temperature difference measured by the thermometer TG of the upstream thermometer TG and the downstream thermometer TG. Controls the polarity reversal operation. For example, if this difference is equal to or less than a predetermined value, the polarity reversing operation of the electrode plate 12 may be performed to start the cleaning process. At this time, the overall control unit 5 may also execute control for stopping the circulation of the working fluid and performing the above-described cleaning process.
In the third modification, the example of detecting the temperature of the first fluid has been described. However, the temperature of the second fluid flowing into the heat exchanger 1 and flowing out of the heat exchanger 1 is detected. Also good.

<< Modification 4 >>
FIG. 11 is a diagram for explaining the fourth modification, and the configuration of the condenser 4 is different from that of the binary power generation system BES1 of the first embodiment described above. That is, in the condenser 41 of Modification ₄ , the electrode plates 12 _{5 to} 12 ₈ corresponding to the electrode plates 12 _{1 to} 12 ₄ described above are arranged in containers as electrolytic cells, respectively. A flow path through which a cold fluid flows and a flow path through which a working fluid (generally in a gas-liquid two-layer state) flows are partitioned.
The main difference between the present modification and the above-described embodiment or modification is that the liquid (first liquid) applied to the purification process is a cold fluid (for example, cold water) flowing into the condenser 4. That is, the “first fluid” of the present invention is not limited to a fluid having a relatively high temperature (hot water, hot water, etc.), and includes a fluid having a relatively low temperature.

Cold liquid flowing through the fifth pipe L ₅ to the condenser 4, in binary power generation is circulated between the example cooling tower and the condenser. As this cold liquid, for example, cold water (cooling water) or a known refrigerant (HFE or the like) can be applied. Therefore, depending on the type of the cold liquid used, it is possible to assume a possibility that some components are deposited.
Therefore, according to this modification, it is possible to perform the purification process on the cold liquid flowing into the condenser 4 and further increase the efficiency of the entire system.

In each of the above-described embodiments and modifications, at least a part of the flow path in the heat exchanger 1 is formed by the electrode plate. However, the present invention is not limited to this. For example, the first pipe L ₁ connected to the heat exchanger ₁ is provided. it may also be drawn into the heat exchanger 1, the first pipe material has high thermal conductivity than the pipe L ₁ may be disposed in the heat exchanger 1.
The electrode plate 12 does not necessarily have a flat plate shape as shown in FIG. 12A. For example, the wave plate having a meandering curved surface as shown in FIG. 12B or 12C. Alternatively, an uneven plate in which concave and convex portions are continuously connected may be applied as the electrode plate 12. When a plurality of electrode plates 12 shown in FIG. 12 (b) or FIG. 12 (c) are used side by side, the same type of electrode plate 12 is used so that the distance between the electrodes is as uniform as possible in the plane of the electrode plate 12. It is desirable to arrange the electrode plates 12 having the same shape in parallel. In addition, it is desirable that the electrode plate 12 is disposed in the electrolytic cell so that the concave portion or the convex portion of the electrode plate 12 extends along the flow direction of the first fluid or the second fluid.

Each embodiment and each modification described above may be combined as appropriate to constitute a geothermal power generation system.
In the above description, the binary power generation system has been described as an example. However, the present invention may be applied to other types of geothermal power generation systems. Furthermore, the present invention may be applied to other power generation systems that perform heat exchange using a fluid, not limited to a geothermal power generation system.

   As described above, the heat exchanger and the power generation system of the present invention are suitable for constructing a low-cost and high-efficiency system.

BES binary power generation system I ammeter P Pressure gauge TG thermometers _L 1 ~L ₆ pipe _e 1 to e ₃ lines 1 heat exchanger 2 the steam turbine (first steam turbine)
3 Generator (1st generator)
4 Condenser 5 Overall Control Device 6 Depressurized Gas-Liquid Separator 7 Steam Control Valve 8 Steam Turbine (Second Steam Turbine)
9 Generator (second generator)
11 Electrolysis cell 12 Electrode plate (cathode plate or anode plate)
13 Control Unit 41 Condenser 100 Heat Exchanger 101 Cleaning Device 102 Container 200 Primary Heat Exchanger 201 Secondary Heat Exchanger

Claims (12)

An anode plate having a first flow path through which the first fluid can flow and a second flow path through which the second fluid for exchanging heat between the first fluid flows and to which a predetermined potential is applied from a power source And an electrolytic cell in which at least a part of the first flow path and the second flow path is partitioned by a cathode plate,
After applying the predetermined potential to the anode plate and the cathode plate and applying the predetermined potential, a cleaning process for applying a potential whose polarity is reversed from the predetermined potential and then canceling the energization is performed. A control unit that performs control repeated every period of
Only including,
The control unit is longer than the period of applying the predetermined potential and the inverted potential of the polarity until the predetermined potential is applied after the energization is started again after the energization is canceled. Thus, the heat exchanger for the power generation system is characterized by performing control to apply potentials to the anode plate and the cathode plate, respectively . The heat exchanger for a power generation system according to claim 1, wherein a plurality of the anode plates and the cathode plates are alternately arranged in the electrolytic cell. A heat exchanger for a power generation system according to claim 1 or 2,
A control device for controlling the power source,
The binary power generation system, wherein the controller reverses the polarity of the anode plate and the cathode plate at a predetermined timing. An ammeter for measuring the current flowing between the anode plate and the cathode plate;
The binary power generation system according to claim 3, wherein the control device reverses the polarity based on a measurement value of the ammeter. A pressure gauge for measuring the pressure of the vapor generated from the second fluid;
The binary power generation system according to claim 3 or 4, wherein the control device reverses the polarity based on a measurement value of the pressure gauge. A thermometer for detecting the temperature of the first liquid flowing into the electrolytic cell and the temperature of the first liquid flowing out of the electrolytic cell;
The binary power generation system according to any one of claims 3 to 5, wherein the controller reverses the polarity based on a measurement value of the thermometer. A first steam turbine driven by medium steam generated by evaporation of the second fluid;
A power supply system that electrically connects the first steam turbine and the anode plate and the cathode plate;
The binary power generation system according to any one of claims 3 to 6, wherein the control device uses at least a part of the electric power generated by the first steam turbine as the power source. A reduced-pressure gas-liquid separator that depressurizes the first fluid and separates it into water vapor and hot water;
The binary power generation system according to claim 7, further comprising: a second steam turbine driven by the steam separated by the decompression gas-liquid separator.   Connected to the heat exchanger or the first pipe through which the first fluid passed through the heat exchanger flows, and the first fluid after the polarity of the anode plate and the cathode plate is reversed can be discharged. The binary power generation system according to any one of claims 3 to 8, further comprising a tube. A valve for switching between the discharge pipe and the first pipe;
10. The control device according to claim 9, wherein when the polarities of the anode plate and the cathode plate are reversed, the control device performs control for switching the valve to flow the thermal fluid introduced into the heat exchanger into the discharge pipe. Binary power generation system.   The binary power generation system according to any one of claims 1 to 10, wherein the first fluid is geothermal water containing a mineral content or a sulfur content. Flowing a first fluid through a first pipe so as to contact the cathode plate into a heat exchanger in which an anode plate and a cathode plate to which a predetermined potential is applied from a power source is disposed;
Circulating a second fluid that exchanges heat with the first fluid into the heat exchanger via a second pipe so as to be isolated from the first fluid in the heat exchanger;
After applying the predetermined potential to the anode plate and the cathode plate and applying the predetermined potential, a cleaning process for applying a potential whose polarity is reversed from the predetermined potential and then canceling the energization is performed. Repeating every cycle,
Only including,
The anode is longer than the period in which the predetermined potential and the potential in which the polarity is inverted are applied, and the period from when the energization is released to when the predetermined potential is applied after the energization is started again. A method of controlling a heat exchanger for a power generation system , wherein a potential is applied to each of the plate and the cathode plate .