Boiler system and boiler system control method

Abstract

A boiler system (1) comprises: a water treatment device (100) that generates acidic water and alkaline water by removing metal ions from treatment target water through electrolysis; a water storage tank (200) that stores the alkaline water; a boiler device (300) that generates steam by using the water in the water storage tank (200); and an electrolytic cell supply path (L2) that supplies, to an electrolytic cell of the water treatment device (100), a liquid obtained from the steam generated by the boiler device, and / or a raw water supply path (L3) that supplies said liquid to upstream of the water treatment device (100).

Description

Boiler system and boiler system control method

[0001] This disclosure relates to a boiler system and a boiler system control method.

[0002] Conventionally, in boiler systems, a technology has been proposed to recover steam generated in a boiler into a feedwater tank that supplies water to the boiler. Patent Document 1 discloses a boiler system that utilizes treated water softened by an ion exchange resin bed. In the boiler system disclosed in Patent Document 1, the condensate obtained by condensing the steam generated in the boiler in a load device is recovered into a feedwater tank.

[0003] Japanese Patent Publication No. 2021-162200

[0004] The boiler system disclosed in Patent Document 1 reuses energy by recovering the steam generated in the boiler as condensate in a load device and storing it in a feedwater tank. In a boiler system, there is surplus thermal energy in addition to the thermal energy generated by the boiler that is supplied to equipment such as load devices, and there is a need to utilize this thermal energy.

[0005] This disclosure has been made in view of the problems of the prior art. The purpose of this disclosure is to provide a boiler system that can effectively utilize the thermal energy generated by the boiler.

[0006] To solve the above problems, a boiler system according to an embodiment of the present disclosure comprises: a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water; a water storage tank for storing alkaline water; a boiler that generates steam using the water in the water storage tank; and an electrolytic cell supply passage that supplies liquid obtained from the steam generated by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply passage that supplies liquid to the upstream of the water treatment device.

[0007] To solve the above problems, a boiler system according to another aspect of the present disclosure comprises: a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water; a water storage tank for storing alkaline water; a boiler device that generates steam using the water in the water storage tank; and a heat supply passage that supplies steam or a liquid obtained from steam to the vicinity of the electrolytic cell of the water treatment device and / or the upstream flow path of the water treatment device.

[0008] To solve the above problems, a boiler system control method according to another aspect of the present disclosure is a boiler system control method that is executed by a computer and controls a boiler system comprising a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water, and a boiler device that generates steam using the alkaline water, wherein the method opens an upstream valve provided in the upstream flow path that supplies water to be treated to the water treatment device, opens a supply path valve that adjusts the flow rate of an electrolytic cell supply path that supplies liquid obtained from the steam generated by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply path that supplies to the upstream of the water treatment device, and the flow rate of a heat supply path that supplies the steam or liquid obtained from the steam to the vicinity of the electrolytic cell and / or the upstream flow path of the water treatment device, starts the water softening treatment by the water treatment device, performs a predetermined electrolysis, stops the water softening treatment by the water treatment device, closes the supply path valve and closes the upstream valve.

[0009] Figure 1 is a schematic diagram showing an example of the configuration of the boiler system according to this embodiment. Figure 2 is a schematic diagram showing an example of the configuration of the water treatment apparatus according to this embodiment. Figure 3 is a schematic diagram showing the state of metal ion movement and insolubilization in the electrolytic cell of the water treatment apparatus according to this embodiment. Figure 4 is a schematic diagram showing the state of hydrogen ion movement and neutralization in the electrolytic cell of the water treatment apparatus according to this embodiment. Figure 5 shows the state of carbonic acid (H) when carbonate ions are dissolved in water. ２ CO ３ ), bicarbonate ions (HCO3) ３ － ) and carbonate ions (CO ３ ２－Figure 6 is a graph showing the relationship between the relative abundance of ) and pH. Figure 7 is a table for explaining the electrolytic control in the water treatment apparatus according to this embodiment. Figure 7 is a graph schematically showing the relationship between the conductivity of the treated water, the ion transfer rate and insolubilization rate of metal ions, and the water softening rate when only constant current control is performed, only constant voltage control is performed, and electrolytic control is performed. Figure 8 is a schematic diagram showing an example of the configuration of a boiler system according to another embodiment. Figure 9 is a schematic diagram showing an example of the configuration of a boiler system according to another embodiment. Figure 10 is a flowchart showing an example of the control of the boiler system according to this embodiment.

[0010] The boiler system 1 according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0011] (Boiler System 1) Figure 1 is a schematic diagram showing an example of the configuration of the boiler system 1 according to this embodiment. The boiler system 1 is composed of a water treatment device 100, a water storage tank 200, and a boiler device 300.

[0012] Furthermore, the boiler system 1 includes first valves 401 to third valves 403 for adjusting the flow rate of water in each path. The boiler system 1 also includes a first water quality sensor 501 and a second water quality sensor 502 for detecting the water quality of the water flowing in each path.

[0013] The water treatment device 100 is a water softening device that generates acidic water and alkaline water from the water to be treated (raw water) by electrolysis. In the example shown in Figure 1, acidic water and alkaline water are generated by electrolysis from the raw water (water to be treated) that enters through the first valve 401 and the first water quality sensor 501, and the alkaline water is supplied to the downstream water storage tank 200. Details of the acidic water and alkaline water generation process in the water treatment device 100 will be described later.

[0014] The alkaline water generated by the water treatment device 100 is supplied to the water storage tank 200 via the second water quality sensor 502 and the second valve 402.

[0015] The water storage tank 200 stores the alkaline water supplied from the water treatment device 100 and supplies it to the downstream boiler device 300. The boiler device 300 uses the water stored in the water storage tank 200 to generate steam. Further, the condensate (drain) obtained from the steam generated by the boiler device 300 is supplied to the water storage tank 200 via the water storage tank supply path L1.

[0016] In the boiler system 1, it is required to effectively utilize the thermal energy such as the drain generated by this boiler device 300. For example, in the boiler system disclosed in Patent Document 1, when the water to be treated heated with the drain is supplied to a soft water generation device using an ion exchange resin, there arises a problem that the resin deteriorates and the soft water generation efficiency decreases.

[0017] On the other hand, in a soft water generation device by electrolysis, crystallization of calcium and magnesium is promoted by heating the water to be treated, and it becomes possible to reduce the time required for soft water generation and the energy to be applied.

[0018] The boiler system 1 according to the present embodiment includes an electrolytic cell supply path L2 that supplies the liquid obtained from the steam generated by the boiler device 300 to the electrolytic cell 10 (see FIG. 2) of the water treatment device 100, or a raw water supply path L3 that supplies it upstream of the water treatment device 100. Note that the liquid obtained from the steam generated by the boiler device 300 is at a higher temperature than the water to be treated. Thereby, the boiler system 1 can heat the water to be treated processed by the water treatment device 100 and reduce the time required for soft water generation and the applied energy.

[0019] When the liquid obtained from the steam generated by the boiler device 300 is supplied to the electrolytic cell 10 via the electrolytic cell supply path L2, it is desirable to supply a small amount so as to warm the water inside the electrolytic cell 10.

[0020] When the liquid obtained from the steam generated by the boiler device 300 is supplied upstream of the water treatment device 100 via the raw water supply path L3, it is supplied to a raw water supply tank (not shown) or an upstream flow path RL.

[0021] As described above, the boiler system 1 according to this embodiment includes a water treatment device 100 that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water, and a water storage tank 200 for storing alkaline water. The boiler system 1 also includes a boiler device 300 that generates steam using the water in the water storage tank 200. Furthermore, the boiler system 1 includes an electrolytic cell supply passage L2 that supplies liquid obtained from the steam generated in the boiler device 300 to the electrolytic cell 10 of the water treatment device 100 and / or a raw water supply passage L3 that supplies liquid upstream of the water treatment device 100.

[0022] As a result, the boiler system 1 heats the water to be treated in the electrolytic cell 10 of the water treatment device 100, which promotes the crystallization of calcium and magnesium in hard water and improves the efficiency of treated water production. Furthermore, the boiler system 1 can produce treated water without wasting energy by utilizing the thermal energy generated in the boiler device 300.

[0023] Furthermore, the liquid obtained from the steam generated by the boiler device 300 of the boiler system 1 is at a higher temperature than the water to be treated. As a result, the boiler system 1 can heat the water to be treated by the water treatment device 100, thereby reducing the time and energy required for soft water production.

[0024] Furthermore, the boiler system 1 may change the amount of drain supplied to the electrolytic cell supply channel L2 that supplies to the electrolytic cell 10 of the water treatment device 100 and / or the raw water supply channel L3 that supplies to the upstream of the water treatment device 100, as well as the energy applied, based on the detection results of the second water quality sensor 502. This makes it possible for the boiler system 1 to more appropriately improve the efficiency of treated water production and suppress wasted energy.

[0025] (Water Treatment Device 100) Next, the details of the water treatment device 100 will be described. As shown in Figure 2, the water treatment device 100 of this embodiment includes an electrolytic cell 10 that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water, a first flow path 20 through which acidic water circulates, and a second flow path 30 through which alkaline water circulates. The water treatment device 100 further includes a water to be treated flow path 40 for supplying water to be treated, a first discharge flow path 50 for discharging treated acidic water from the first flow path 20, and a second discharge flow path 60 for discharging treated alkaline water from the second flow path 30.

[0026] As shown in Figures 2 and 3, the electrolytic cell 10 comprises a solution tank 11, an anode 12, a cathode 13, and an ion-permeable membrane (ion-permeable membrane 14). The solution tank 11 is a container that holds the water to be treated, which contains metal ions, and electrolyzes the water held inside, as will be described later.

[0027] The anode 12 and cathode 13 are an electrode pair for electrolyzing the water to be treated in the solution tank 11. The anode 12 is located in the anode chamber 15, and the cathode 13 is located in the cathode chamber 16. The anode 12 and cathode 13 are arranged inside the solution tank 11, facing each other with an ion-permeable membrane 14 in between. The anode 12 is electrically connected to the positive electrode of the electrolysis power supply 90, and the cathode 13 is electrically connected to the negative electrode of the electrolysis power supply 90.

[0028] The ion-permeable membrane 14 is placed inside the solution tank 11 and divides the solution tank 11 into an anode chamber 15 and a cathode chamber 16. In other words, the anode chamber 15 is partitioned from a part of the solution tank 11 by the ion-permeable membrane 14, and the cathode chamber 16 is partitioned from the other part of the solution tank 11 by the ion-permeable membrane 14. The ion-permeable membrane 14 is a component that allows metal ions in the water to be treated to pass through. Therefore, the ion-permeable membrane 14 is not particularly limited as long as it is capable of allowing metal ions to pass through, and for example, a porous membrane or a cation exchange membrane can be used. Furthermore, the material of the porous membrane can be, for example, a ceramic material, a resin material, or a metal material, but is not particularly limited.

[0029] A first flow path 20 is connected to the anode chamber 15 of the electrolytic cell 10. In other words, the first flow path 20 is connected to the inlet 15a and outlet 15b of the anode chamber 15, respectively. In the first flow path 20, an acidic water tank 21 for temporarily storing acidic water and a first circulation pump 22 for pumping acidic water are located downstream of the anode chamber 15. Therefore, acidic water flowing out from the outlet 15b of the anode chamber 15 can pass through the acidic water tank 21 and the first circulation pump 22 and flow into the interior of the anode chamber 15 from the inlet 15a.

[0030] Similarly, a second flow path 30 is connected to the cathode chamber 16 of the electrolytic cell 10. In other words, the second flow path 30 is connected to the inlet 16a and outlet 16b of the cathode chamber 16, respectively. In the second flow path 30, an alkaline water tank 31 for temporarily storing alkaline water and a second circulation pump 32 for pumping alkaline water are located downstream of the cathode chamber 16. Therefore, alkaline water flowing out from the outlet 16b of the cathode chamber 16 can pass through the alkaline water tank 31 and the second circulation pump 32 and flow into the interior of the cathode chamber 16 from the inlet 16a.

[0031] The treated water channel 40 is a channel that supplies treated water to the electrolytic cell 10. Specifically, the treated water channel 40 branches into two channels and is connected to a first channel 20 and a second channel 30. Therefore, the treated water is supplied to both the first channel 20 and the second channel 30 through the treated water channel 40. The treated water channel 40 is also equipped with an electric valve 41 that switches between allowing and stopping the flow of treated water.

[0032] The first outflow channel 50 is connected to the downstream side of the first circulation pump 22 via a first electric valve 51. As will be described later, the first outflow channel 50 is a channel for discharging acidic water that has been treated to soften water in the electrolytic cell 10. A faucet 52 is provided at the end of the first outflow channel 50 to switch between allowing and stopping the flow of the treated acidic water. The treated water discharged from the first outflow channel 50 is treated water from which metal ions have been removed or reduced, and can be suitably utilized.

[0033] In the water treatment apparatus 100 according to this embodiment, the electric valve 41, the first electric valve 51, the second electric valve 61, and the faucet 52 are all general electric valves driven by actuators using a motor (electric motor). However, the valves used in the water treatment apparatus 100 are not limited to electric valves, and may be composed of, for example, electromagnetic valves driven by actuators (solenoids).

[0034] The second outflow channel 60 is connected to the downstream side of the second circulation pump 32 via a second electric valve 61. As will be described later, the second outflow channel 60 is a channel for discharging alkaline water that has been insolubilized in the electrolytic cell 10. The end of the second outflow channel 60 is connected to a faucet 52. The faucet 52 allows switching between the flow and shutoff of alkaline water that has been treated to remove insolubilized substances and softened by the filter 62. The treated water discharged from the second outflow channel 60 is water from which metal ions have been removed or reduced and can be suitably utilized.

[0035] The second outflow channel 60 is provided with a filter 62 for separating and removing insoluble substances consisting of metal ions that have been insoluble in the electrolytic cell 10. The filter 62 is not particularly limited as long as it can remove the insoluble substances, but a cartridge-type filter, a filtration layer using granular filter media, a cyclone-type solid-liquid separator, a hollow fiber membrane, etc., can be used.

[0036] As shown in Figure 2, a bypass channel 53 may be connected to the first electric valve 51 for supplying the softened acidic water to the filter 62. The acidic water that has been softened in the electrolytic cell 10 and is circulating in the first channel 20 has had its insoluble matter sufficiently reduced, but if necessary, the acidic water may be filtered by the filter 62 before being supplied to the faucet 52. In addition, a bypass channel 63 may be connected to the second electric valve 61 for supplying the alkaline water that has been insolublely treated in the electrolytic cell 10 directly to the faucet 52 without supplying it to the filter 62.

[0037] As shown in Figure 2, the water treatment apparatus 100 of this embodiment includes a first conductivity measuring unit 70 for measuring the conductivity of water flowing through the anode chamber and a second conductivity measuring unit 80 for measuring the conductivity of water flowing through the cathode chamber. In this specification, water flowing through the anode chamber is also referred to as anode water, and water flowing through the cathode chamber is also referred to as cathode water. The first conductivity measuring unit 70 is provided on the inlet 15a side of the anode chamber 15 in the first flow path 20, and the second conductivity measuring unit 80 is provided on the inlet 16a side of the cathode chamber 16 in the second flow path 30. However, the location of the first conductivity measuring unit 70 is not particularly limited as long as it can measure the conductivity of the anode water, and it may be provided, for example, inside the anode chamber 15 or inside the acidic water tank 21. Similarly, the location where the second conductivity measuring unit 80 is installed is not particularly limited as long as it can measure the conductivity of the cathode water. For example, it may be installed inside the cathode chamber 16 or inside the alkaline water tank 31.

[0038] The first conductivity measuring unit 70 and the second conductivity measuring unit 80 are connected to a control unit 101, which will be described later, and transmit the numerical values ​​of the conductivity of the anode water and cathode water measured by the first conductivity measuring unit 70 and the second conductivity measuring unit 80 to the control unit 101.

[0039] The water treatment apparatus 100 further includes an electrolytic power supply 90 and a control unit 101. The electrolytic power supply 90 is electrically connected to the anode 12 and the cathode 13. The electrolytic power supply 90 then flows current and applies voltage between the anode 12 and the cathode 13.

[0040] The control unit 101 is connected to the electrolytic power supply 90 and adjusts the voltage between the anode and cathode by controlling the electrolytic power supply 90. The control unit 101 is also connected to the electric valve 41, the first electric valve 51, the second electric valve 61, and the faucet 52 of the water to be treated flow path 40 and controls their opening and closing. Furthermore, the control unit 101 is connected to the first circulation pump 22 and the second circulation pump 32 and controls their operation.

[0041] Incidentally, when the control unit 101 executes operations based on a control program, it may include a storage device such as a ROM (Read Only Memory) or a RAM (Random Access Memory) that stores the control program. Further, the control unit 101 may include a microcomputer that executes the control program. Also, when the control unit 101 executes predetermined operations, it may include a dedicated electronic circuit or the like in which the control program is realized in hardware. Furthermore, the control unit 101 may include a timing unit such as an RTC (Real Time Clock) to measure time. Additionally, the control unit 101 may include a measurement unit 120 that measures conductivity based on the values measured by the conductivity sensors provided in the first conductivity measurement unit 70 and the second conductivity measurement unit 80.

[0042] When the water treatment apparatus 100 configured as described above operates, the following events are assumed. First, the conductivity of acidic water is in a proportional relationship with the ion concentration in the acidic water. Therefore, the conductivity of acidic water is in a proportional relationship with the concentration (hardness) of metal ions contained in the acidic water. Similarly, the conductivity of alkaline water is in a proportional relationship with the ion concentration in the alkaline water. Therefore, the conductivity of alkaline water is in a proportional relationship with the concentration (hardness) of metal ions contained in the alkaline water.

[0043] Next, when voltage is applied to the anode 12 and the cathode 13 with the water to be treated in the anode chamber 15 and the cathode chamber 16 of the electrolytic cell 10, as shown in FIG. 3, metal ions in the anode chamber 15 permeate the ion permeable membrane 14 and move to the cathode chamber 16. That is, as shown by the electrophoresis velocity formula of Equation 1, the velocity ν (m / s) of ion electrophoresis is expressed as the product of the ion mobility μ (m ２ / Vs) and the electric field E (V / m). Therefore, the movement of metal ions depends on the magnitude of the voltage (electric field). As shown in FIG. 4, when voltage is applied to the anode 12 and the cathode 13, hydrogen ions (H ＋ ) in the anode chamber 15 also move to the cathode chamber 16 and react with hydroxide ions (OH － ) to neutralize. [Equation 1] ν = μE

[0044] Next, when the water to be treated is placed in the anode chamber 15 and cathode chamber 16 of the electrolytic cell 10 and electrolyzed, as shown in Figure 4 and Chemical Formula 1, hydrogen ions (H) are produced at the anode 12 by oxidation reaction. ＋ ) is generated, and at cathode 13, hydroxide ions (OH) are produced by a reduction reaction. － ) is produced. Note that this type of water electrolysis depends on the magnitude of the current. [Chemical Formula 1] Anode 12:2H ２ O → 4H ＋ +4e － +O ２ ↑ Cathode 13:4H ２ O+4e － → 4OH － +2H ２ ↑

[0045] And, magnesium ions (Mg) contained in the water to be treated ２＋ ) reacts with the generated hydroxide ions to form magnesium hydroxide (Mg(OH) ２ ) and becomes insoluble. Here, the solubility product K of magnesium hydroxide in water at 25°C. ｓｐ is 1.80 x 10 －１１ (mol / L) ３ And, as shown in equation 2, Mg ２＋ and OH － The ion product with the solubility product K ｓｐ If it becomes larger than that, Mg(OH) ２ The dissolution equilibrium shifts in the direction that Mg(OH) is produced, ２ An insoluble compound consisting of the above is formed. Therefore, in order to efficiently insolubilize magnesium ions, it is necessary to increase the pH, that is, to increase the hydroxide ions. [Equation 2] K ｓｐ <[Mg ２＋ ] [OH － ] ２

[0046] Furthermore, carbonate ions (CO2) are produced in the treated water due to the dissolution of carbonates from minerals and carbon dioxide from the air. ３ ２－ ) is included. And, calcium ions (Ca) contained in the water to be treated ２＋) reacts with carbonate ions to form calcium carbonate (CaCO3). ３ ) and becomes insoluble. Here, the solubility product K of calcium carbonate in water at 25°C. ｓｐ is 4.96 x 10 －９ (mol / L) ２ And, as shown in equation 3, Ca ２ + and CO ３ － The ion product with the solubility product K ｓｐ If it becomes larger than that, CaCO2 ３ Because the dissolution equilibrium shifts in the direction of CaCO2 formation, ３ An insoluble compound consisting of the above is formed. [Mathematics 3] K ｓｐ <[Ca ２＋ ] [CO ３ － ]

[0047] Here, in Figure 5, the carbonic acid (H) is shown when carbonate ions are dissolved in water. ２ CO ３ ), bicarbonate ions (HCO3) ３ － ) and carbonate ions (CO ３ ２－ This shows the relationship between the relative abundance of ions and pH. From Figure 5, it can be seen that the more alkaline the pH of water, the less carbonic acid and bicarbonate ions there are, and the more carbonate ions there are. Therefore, in order to efficiently insolubilize calcium ions, it is necessary to increase the pH and thus increase the carbonate ions.

[0048] Thus, the insolubilization of magnesium and calcium ions increases as the concentration of hydroxide ions increases. Furthermore, the electrolysis of water depends on the magnitude of the electric current. Therefore, the insolubilization of magnesium and calcium ions also depends on the magnitude of the electric current.

[0049] Next, based on the above-mentioned events, the operation of the water treatment apparatus 100 of this embodiment will be described. First, the control unit 101 opens the electric valve 41 and injects the raw water to be treated into the water to be treated flow path 40, the first flow path 20, and the second flow path 30. Furthermore, it injects the water to be treated into the anode chamber 15 and the cathode chamber 16 of the electrolytic cell 10, as well as the acidic water tank 21 and the alkaline water tank 31.

[0050] Next, the control unit 101 measures the conductivity of the anode water and cathode water using the first conductivity measuring unit 70 and the second conductivity measuring unit 80. Furthermore, the control unit 101 controls the electrolytic power supply 90 to flow current between the anode 12 and the cathode 13 to electrolyze the water to be treated. The control unit 101 also operates the first circulation pump 22 and the second circulation pump 32 to circulate the water to be treated in the first flow path 20 and the second flow path 30. By performing electrolysis and circulation of the water to be treated for a predetermined time, the water to be treated in the anode chamber 15, the first flow path 20 and the acidic water tank 21 becomes acidic water, and the water to be treated in the cathode chamber 16, the second flow path 30 and the alkaline water tank 31 becomes alkaline water.

[0051] The control unit 101 then measures the conductivity of the anode water (acidic water) and cathode water (alkaline water) at predetermined intervals. If the metal ions in the acidic and alkaline water have not been removed, both the acidic and alkaline water will have high conductivity, as shown in "(1) Insoluble Substance Formation" in Figure 6. Therefore, the control unit 101 controls the electrolytic power supply 90 to supply a constant current between the anode 12 and the cathode 13. This constant current control can be achieved by adjusting the current or voltage applied between the anode 12 and the cathode 13.

[0052] As mentioned above, the insolubilization of metal ions is current-dependent; therefore, constant current control promotes the insolubilization of metal ions in alkaline water. As a result, the concentration of metal ions decreases, and the conductivity of alkaline water declines. However, in acidic water, the insolubilization of metal ions is less likely to occur, so the conductivity remains high.

[0053] Next, if the conductivity measurement shows that the conductivity of alkaline water has decreased but the conductivity of acidic water remains high, the control unit 101 controls the electrolytic power supply 90 to apply a constant voltage between the anode 12 and the cathode 13, as shown in "(2) Ion Transfer" in Figure 6. This constant voltage control can be achieved by adjusting the voltage applied between the anode 12 and the cathode 13.

[0054] As described above, electrophoresis, in which metal ions move from the anode chamber 15 to the cathode chamber 16, is voltage-dependent. Therefore, when constant voltage control is performed, metal ions in the acidic water of the anode chamber 15 permeate the ion-permeable membrane 14 and move to the cathode chamber 16. As a result, the concentration of metal ions in the alkaline water of the cathode chamber 16 increases, and the conductivity of the alkaline water increases. Conversely, the concentration of metal ions in the acidic water decreases, and the conductivity of the acidic water decreases.

[0055] Here, as described above, when a constant voltage is applied to the anode 12 and cathode 13, hydrogen ions (H) present in the anode chamber 15 ＋ As the ions move to the cathode chamber 16, a neutralization reaction occurs and the pH decreases. If the pH of the alkaline water in the cathode chamber 16 decreases, the insolubilization of metal ions is suppressed. Therefore, if the control unit 101 measures the conductivity after constant current control and finds that the conductivity of the alkaline water has decreased but the conductivity of the acidic water has remained high, it calculates a voltage value that can maintain a high pH for the alkaline water. For example, the control unit 101 calculates and applies a voltage value that can maintain the pH of the alkaline water at 11 or higher.

[0056] Next, if the conductivity of alkaline water increases but the conductivity of acidic water decreases as a result of the conductivity measurement, the control unit 101 controls the electrolytic power supply 90 to flow a constant current between the anode 12 and the cathode 13, as shown in "(3) Insoluble matter formation" in Figure 6. This constant current control can be performed by adjusting the current or voltage applied between the anode 12 and the cathode 13.

[0057] As mentioned above, the insolubilization of metal ions is current-dependent; therefore, constant current control promotes the insolubilization of metal ions in alkaline water. As a result, the concentration of metal ions decreases, and the conductivity of alkaline water decreases.

[0058] Next, if the conductivity of both the acidic water and the alkaline water decreases as a result of measuring the conductivity, the control unit 101 determines that the water softening process has progressed for both the acidic water and the alkaline water, as shown in "(4) Water softening" in Figure 6.

[0059] In this manner, the control unit 101 measures the conductivity of the anode water and cathode water, then adjusts the voltage applied between the anode 12 and cathode 13 to perform electrolytic control by repeatedly switching between constant current control and constant voltage control. As a result, metal ions in the acidic water side undergo electrophoresis to the alkaline water side, and metal ions become insoluble in the alkaline water side, thus reducing the amount of metal ions in the water being treated. In this embodiment, the time taken for the electrolytic control is measured by the timing unit of the control unit 101, so the electrolytic control is performed until a predetermined time has elapsed.

[0060] Subsequently, the control unit 101 adjusts the first electric valve 51 to allow the acidic water in the first flow path 20 to flow into the first outlet flow path 50. The control unit 101 also adjusts the second electric valve 61 to allow the alkaline water in the second flow path 30 to flow into the second outlet flow path 60. The alkaline water then passes through the filter 62 provided in the second outlet flow path 60. Since the alkaline water flowing into the second outlet flow path 60 contains insoluble metal ions, these insoluble ions are removed as the alkaline water passes through the filter 62. By opening the faucet 52, the user can then use the softened acidic water and alkaline water. At this time, by arbitrarily mixing the acidic water and alkaline water, neutral treated water (neutral water) can be used.

[0061] Here, Figure 7 shows the relationship between the conductivity of the treated water, the ion transfer rate and insolubilization rate of metal ions, and the water softening rate when the control unit 101 performs only constant voltage control, which applies a constant voltage to the anode 12 and cathode 13 of the electrolytic cell 10 regardless of conductivity. Also, Figure 7 shows the relationship between the conductivity of the treated water, the ion transfer rate and insolubilization rate of metal ions, and the water softening rate when the control unit 101 performs only constant current control, which applies a constant current to the anode 12 and cathode 13 of the electrolytic cell 10 regardless of conductivity. Note that "ion transfer rate of metal ions" indicates the efficiency of metal ions moving from the anode chamber 15 to the cathode chamber 16. "Insolubilization rate of metal ions" indicates the efficiency of metal ions binding with hydroxide ions and carbonate ions and becoming insoluble. "Water softening rate" indicates the efficiency of metal ions being removed from the treated water.

[0062] As described above, the movement of metal ions depends on voltage (electric field). Therefore, when the control unit 101 performs constant voltage control, metal ions move from the anode chamber 15 to the cathode chamber 16 regardless of the conductivity of the water being treated, meaning that a high ion transfer rate can be maintained. However, since the insolubilization of metal ions depends on current, when constant voltage control is performed, the insolubilization rate improves when the conductivity of the water being treated is high, but decreases when the conductivity is low. Therefore, if the control unit 101 performs only constant voltage control and not constant current control, the water can be efficiently softened and the softening rate increased when the conductivity of the water being treated is high, i.e., when the concentration of metal ions is high. However, when the conductivity of the water being treated is low, i.e., when the concentration of metal ions is low, the insolubilization rate decreases, and therefore the softening rate also decreases. Thus, when the control unit 101 performs only constant voltage control, the softening rate is good when the concentration of metal ions is high, but the softening rate deteriorates when the concentration of metal ions is low.

[0063] In contrast, since the insolubilization of metal ions depends on the current, when the control unit 101 performs constant current control, metal ions are insolubilized regardless of the conductivity of the water being treated, meaning that a high insolubilization rate can be maintained. However, as mentioned above, since the movement of metal ions depends on the voltage, when constant current control is performed, the ion movement rate improves when the conductivity of the water being treated is low, but decreases when the conductivity is high. Therefore, if the control unit 101 performs only constant current control and not constant voltage control, it can efficiently soften the water and increase the water softening rate when the conductivity of the water being treated is low, i.e., when the concentration of metal ions is low. However, when the conductivity of the water being treated is high, i.e., when the concentration of metal ions is high, the ion movement rate decreases, and the water softening rate also decreases. Thus, when the control unit 101 performs only constant current control, the water softening rate is good when the concentration of metal ions is low, but the water softening rate deteriorates when the concentration of metal ions is high.

[0064] In the water treatment apparatus 100 of this embodiment, electrolytic control is performed by repeatedly switching between constant current control and constant voltage control by adjusting the voltage applied between the anode 12 and the cathode 13 according to the conductivity (hardness) of the anodic water and cathode water. As a result, the ion transfer rate and insolubilization rate are always kept high, and as a result, it is possible to obtain the desired water softening rate regardless of conductivity.

[0065] Furthermore, in the water treatment apparatus 100 of this embodiment, the first flow path 20 and the second flow path 30 are circulating flow paths. However, the water treatment apparatus is not limited to this configuration, and one-pass flow paths that do not circulate water may be used as the first and second flow paths. Moreover, a combination of a circulating flow path and a one-pass flow path may be used as the first and second flow paths. For this reason, in this specification, the circulating flow path and the one-pass flow path are collectively referred to as the "first flow path." Similarly, the circulating flow path and the one-pass flow path are collectively referred to as the "second flow path."

[0066] (Other Embodiments) Although these embodiments have been described above, the embodiments are not limited to these, and various modifications are possible within the scope of the gist of the embodiments. Furthermore, it is possible to combine some or all of the various embodiments to create new embodiments.

[0067] Figure 8 is a schematic diagram showing an example of the configuration of a boiler system 2 according to another embodiment. The boiler system 2 shown in Figure 8 differs from the boiler system 1 described above in that it is equipped with a solid-liquid separator 600 in the liquid supply passage LL upstream of the electrolytic cell supply passage L2 and / or raw water supply passage L3.

[0068] The condensate from the boiler system 300 may contain iron oxide, which is formed from the oxidation of the metal parts of the boiler system 300. If this iron oxide mixes with the electrolytic cell 10 of the water treatment device 100 or the water to be treated upstream of the water treatment device 100, the efficiency of the water softening process will decrease.

[0069] Therefore, the solid-liquid separator 600 has the function of separating iron oxide, which is a solid component contained in the condensate (drain), from the liquid. As a result, the water treatment device 100 of the boiler system 2 can perform water softening treatment more efficiently by using the condensate from which the solid iron oxide has been removed. Since the iron oxide supplied to the water storage tank 200 accumulates at the bottom of the water storage tank 200, the boiler system 2 discharges the iron oxide accumulated at the bottom of the water storage tank 200 at a predetermined timing and by a predetermined means.

[0070] Figure 9 is a schematic diagram showing an example of the configuration of a boiler system 3 according to another embodiment. The boiler system 3 shown in Figure 9 differs from the boiler system 1 described above in that it includes a heat supply path HL1 and / or HL2 that supplies steam to the vicinity of the electrolytic cell 10 of the water treatment device 100.

[0071] As shown by the dashed line in Figure 9, the heat supply channel HL1 separates the heated gas from the liquid supply channel LL, and the heated gas passes near the water treatment device 100 and is supplied to the water storage tank 200. As a result, in the boiler system 3, the electrolytic cell 10 of the water treatment device 100 is heated, which promotes the crystallization of calcium and magnesium, making it possible to reduce the time and energy required to produce soft water.

[0072] Furthermore, as shown by the dashed line in Figure 9, the heat supply channel HL2 separates the heated gas from the liquid supply channel LL, and the heated gas passes near the upstream channel RL of the water treatment device 100 and is supplied to the water storage tank 200. As a result, in the boiler system 3, the water to be treated supplied to the electrolytic cell 10 of the water treatment device 100 is heated, which promotes the crystallization of calcium and magnesium, making it possible to reduce the time required and the energy applied for soft water production.

[0073] In the example shown in Figure 9, a configuration is shown in which the boiler system 1 shown in Figure 1 is equipped with heat supply passages HL1 and HL2. However, for example, a configuration in which the boiler system 2 shown in Figure 8 is equipped with heat supply passages HL1 and HL2 may also be used. Furthermore, in the example shown in Figure 9, an example is shown in which the heated gas passes near the electrolytic cell 10 and the upstream flow path RL via the heat supply passages HL1 and HL2, which are indicated by dashed lines. However, this configuration is not limited to the embodiment. For example, a configuration in which liquid obtained from steam (gas) flows through the heat supply passages HL1 and HL2, and the heated liquid passes near the electrolytic cell 10 and / or the upstream flow path RL may be used. Moreover, by installing the water treatment device 100 near the heat source of the boiler device 300 and heating the electrolytic cell 10, the effects obtained when the electrolytic cell 10 is heated as described above can be obtained.

[0074] Furthermore, boiler systems 1, 2, and 3 may be configured such that the liquid or steam obtained from the steam heats the water treatment device 100. Specifically, boiler systems 1, 2, and 3 may be configured to heat the acidic water tank 21, the alkaline water tank 31, the first flow path 20, the second flow path 30, and the water to be treated flow path 40. This allows boiler system 1 to reduce the energy supplied to boiler device 300 by increasing the temperature of the liquid supplied to boiler device 300.

[0075] Furthermore, boiler systems 1, 2, and 3 may be equipped with a downstream water treatment device between the water treatment device 100 and the water storage tank 200. The downstream water treatment device is, for example, an ion exchange resin or a water softening device using electrolysis. This allows boiler systems 1, 2, and 3 to further reduce the hardness of the treated water and prevent scale formation in the boiler device 300 that uses the softened water. When the downstream water treatment device is made of an ion exchange resin, it is preferable not to heat it in order to prevent a decrease in water softening efficiency due to resin degradation. When the downstream water treatment device is installed downstream of the water treatment device 100 in boiler systems 1, 2, and 3, the temperature of the treated water decreases when treated water is supplied to the downstream water treatment device, which reduces damage to the ion exchange resin.

[0076] Figure 10 is a flowchart illustrating an example of the control of boiler systems 1, 2, and 3 according to this embodiment. The control of boiler systems 1, 2, and 3 is performed by a control unit composed of a general-purpose microcomputer. In this case, the microcomputer may have a computer program installed that allows it to function as boiler systems 1, 2, and 3. By executing the computer program, the microcomputer functions as one of the multiple information processing circuits provided by boiler systems 1, 2, and 3.

[0077] In this embodiment, an example is shown in which the multiple information processing functions of boiler systems 1, 2, and 3 are realized by software. Boiler systems 1, 2, and 3 function as multiple information processing circuits by executing a computer program.

[0078] Alternatively, boiler systems 1, 2, and 3 can be configured by providing dedicated hardware for executing each information processing function, and these information processing functions can be configured using a system LSI (Large Scale Integration) or the like. Furthermore, multiple information processing functions may be configured using separate hardware components.

[0079] In step S1001, the control unit opens the upstream valve located in the upstream channel RL that supplies the water to be treated to the water treatment device 100. The upstream valve corresponds to the first valve 401. The process then proceeds to step S1002.

[0080] In step S1002, the control unit opens the supply valve. The supply valve adjusts the flow rate of the electrolytic cell supply channel L2, which supplies liquid obtained from steam generated in the boiler device 300 to the electrolytic cell 10 of the water treatment device 100, and / or the raw water supply channel L3, which supplies to the upstream of the water treatment device 100. The supply valve also adjusts the flow rate of the heat supply channels HL1 and HL2, which supply steam generated in the boiler device 300 or liquid obtained from steam to the vicinity of the upstream flow channel RL of the electrolytic cell 10 and / or the water treatment device 100. The supply valve corresponds to the third valve 403. The process then proceeds to step S1003.

[0081] In step S1003, the control unit starts the water softening treatment using the water treatment device 100. The treatment then proceeds to step S1004.

[0082] In step S1004, the control unit stops the water softening treatment by the water treatment device 100 after performing a predetermined electrolysis. The predetermined electrolysis is considered to have reached predetermined standards for the hardness, pH, conductivity, turbidity, and electrolysis time of the treated water. The hardness, pH, conductivity, turbidity, and electrolysis time of the treated water can be detected, for example, by the second water quality sensor 502. The treatment then proceeds to step S1005.

[0083] In step S1005, the control unit closes the supply valve. The process then proceeds to step S1006.

[0084] In step S1006, the control unit closes the upstream valve. The process then ends.

[0085] By performing the processes described in steps S1001 to S1006 above, the boiler systems 1, 2, and 3 heat the water to be treated in the electrolytic cell 10 of the water treatment device 100, promoting the crystallization of calcium and magnesium in hard water and improving the efficiency of treated water production. Furthermore, by utilizing the thermal energy generated in the boiler device 300, the boiler systems 1, 2, and 3 can produce treated water without consuming unnecessary energy.

[0086] Furthermore, the computer program (boiler system control program) that causes a computer to execute the boiler system control method described above, and the computer-readable recording medium on which the program is stored, are included within the scope of this embodiment. Here, the type of computer-readable recording medium is arbitrary. Also, the computer program described above is not limited to that stored on the recording medium described above, but may be transmitted via telecommunications lines, wireless or wired communication lines, networks such as the Internet, etc.

[0087] (Note) The above description of embodiments discloses the following technology.

[0088] (Technology 1) A boiler system comprising: a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water; a water storage tank for storing the alkaline water; a boiler device that generates steam using the water in the water storage tank; and an electrolytic cell supply passage that supplies the liquid obtained from the steam generated by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply passage that supplies the liquid to the upstream of the water treatment device.

[0089] With this configuration, the boiler system 1 improves the efficiency of treated water production by promoting the crystallization of calcium and magnesium in hard water through heating of the water treatment device 100's electrolytic cell 10. Furthermore, the boiler system 1 can produce treated water without wasting energy by utilizing the thermal energy generated by the boiler device 300.

[0090] (Technology 2) A boiler system comprising: a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water; a water storage tank for storing the alkaline water; a boiler device that generates steam using the water in the water storage tank; and a heat supply path that supplies the steam or a liquid obtained from the steam to the vicinity of the electrolytic cell of the water treatment device and / or the upstream flow path of the water treatment device.

[0091] With this configuration, the electrolytic cell 10 of the water treatment device 100 in the boiler system 3 is heated, which promotes the crystallization of calcium and magnesium, thereby reducing the time required and the energy applied for soft water production.

[0092] (Technical 3) The boiler system according to Technical 1 or 2, wherein the liquid obtained from the steam is at a higher temperature than the water to be treated.

[0093] With this configuration, the boiler systems 1, 2, and 3 can heat the water to be treated by the water treatment device 100, thereby reducing the time required for soft water production and the energy applied.

[0094] (Technology 4) A boiler system according to any one of Techniques 1 to 3, further comprising a solid-liquid separator in the electrolytic cell supply channel and / or the liquid supply channel upstream of the raw water supply channel.

[0095] This configuration allows the water treatment device 100 of the boiler system 2 to perform water softening more efficiently by utilizing the condensate from which the solid iron oxide has been removed.

[0096] (Technology 5) A boiler system according to any one of Technologies 1 to 4, further comprising a control unit, wherein the control unit opens an upstream valve provided in an upstream channel that supplies water to be treated to the water treatment device, opens a supply channel valve that adjusts the flow rate of an electrolytic cell supply channel that supplies liquid obtained from the steam generated by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply channel that supplies to the upstream of the water treatment device, and the flow rate of a heat supply channel that supplies the steam or liquid obtained from the steam to the vicinity of the electrolytic cell and / or the upstream channel of the water treatment device, starts the water softening treatment by the water treatment device, stops the water softening treatment by the water treatment device after performing a predetermined electrolysis, closes the supply channel valve, closes the upstream valve, and causes a computer to execute the process.

[0097] With this configuration, the boiler systems 1, 2, and 3 heat the water to be treated in the electrolytic cell 10 of the water treatment device 100, promoting the crystallization of calcium and magnesium in hard water and improving the efficiency of treated water production. Furthermore, by utilizing the thermal energy generated in the boiler device 300, the boiler systems 1, 2, and 3 can produce treated water without consuming unnecessary energy.

[0098] (Technical 6) A boiler system control method for controlling a boiler system comprising a water treatment device, which is executed by computer and removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water, and a boiler device that uses the alkaline water to produce steam, the method comprising: opening an upstream valve provided in the upstream flow path that supplies water to be treated to the water treatment device; opening a supply path valve that adjusts the flow rate of an electrolytic cell supply path that supplies liquid obtained from the steam produced by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply path that supplies to the upstream of the water treatment device, and the flow rate of a heat supply path that supplies the steam or liquid obtained from the steam to the vicinity of the electrolytic cell and / or the upstream flow path of the water treatment device; starting a water softening treatment by the water treatment device; stopping the water softening treatment by the water treatment device after performing a predetermined electrolysis; closing the supply path valve; and closing the upstream valve.

[0099] With this configuration, the boiler system control method heats the water to be treated in the electrolytic cell 10 of the water treatment device 100, promoting the crystallization of calcium and magnesium in hard water and improving the efficiency of treated water production. Furthermore, by utilizing the thermal energy generated by the boiler device 300, the boiler system control method makes it possible to produce treated water without consuming unnecessary energy.

[0100] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment.

[0101] The entire contents of Japanese Patent Application No. 2024-230961 (Filing Date: December 26, 2024) are incorporated herein by reference.

[0102] According to this disclosure, it is possible to provide a boiler system that can effectively utilize the thermal energy generated by the boiler.

[0103] 1, 2, 3 Boiler system 10 Electrolytic cell 100 Water treatment device 101 Control unit 200 Water storage tank 300 Boiler device 401 First valve 402 Second valve 403 Third valve 501 First water quality sensor 502 Second water quality sensor 600 Solid-liquid separation device HL1, HL2 Heat supply path LL Liquid supply path L1 Water storage tank supply path L2 Electrolytic cell supply path L3 Raw water supply path RL Upstream path

Claims

1. A boiler system comprising: a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water; a water storage tank for storing the alkaline water; a boiler device that generates steam using the water in the water storage tank; and an electrolytic cell supply passage that supplies the liquid obtained from the steam generated by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply passage that supplies the liquid to the upstream of the water treatment device.

2. A boiler system comprising: a water treatment device that removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water; a water storage tank for storing the alkaline water; a boiler device that generates steam using the water in the water storage tank; and a heat supply path that supplies the steam or a liquid obtained from the steam to the vicinity of the electrolytic cell of the water treatment device and / or the upstream flow path of the water treatment device.

3. The boiler system according to claim 1 or 2, wherein the liquid obtained from the steam is at a higher temperature than the water to be treated.

4. The boiler system according to claim 1, further comprising a solid-liquid separator in the electrolytic cell supply channel and / or the liquid supply channel upstream of the raw water supply channel.

5. A boiler system according to any one of claims 1 to 4, further comprising a control unit, wherein the control unit opens an upstream valve provided in an upstream channel that supplies water to be treated to the water treatment device, opens a supply channel valve that adjusts the flow rate of an electrolytic cell supply channel that supplies liquid obtained from the steam generated by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply channel that supplies to the upstream of the water treatment device, and the flow rate of a heat supply channel that supplies the steam or liquid obtained from the steam to the vicinity of the electrolytic cell and / or the upstream channel of the water treatment device, starts a water softening treatment by the water treatment device, stops the water softening treatment by the water treatment device after performing a predetermined electrolysis, closes the supply channel valve, closes the upstream valve, and causes a computer to perform the treatment.

6. A boiler system control method for controlling a boiler system comprising a water treatment device, which is operated by a computer and removes metal ions from water to be treated by electrolysis to produce acidic water and alkaline water, and a boiler device that uses the alkaline water to produce steam, the method comprising: opening an upstream valve provided in the upstream flow path that supplies water to be treated to the water treatment device; opening a supply path valve that adjusts the flow rate of an electrolytic cell supply path that supplies liquid obtained from the steam produced by the boiler device to the electrolytic cell of the water treatment device and / or a raw water supply path that supplies to the upstream of the water treatment device, and the flow rate of a heat supply path that supplies the steam or liquid obtained from the steam to the vicinity of the electrolytic cell and / or the upstream flow path of the water treatment device; starting a water softening treatment by the water treatment device; stopping the water softening treatment by the water treatment device after performing a predetermined electrolysis; closing the supply path valve; and closing the upstream valve.

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