JP2014066479A - Temperature control water feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent etching of electrodes by reversion of polarity in a temperature control water feeder with an electrolyser.SOLUTION: A temperature control water feeder comprises: a water heat exchanger heating water; an electrolyser for removing composition of scale included in water sent to the water heat exchanger; and a control unit. The electrolyser comprises: a container 47 having a water inlet 43 and a water outlet 45, and an electrode pair 49 provided within the container 47. When polarity of the electrode pair 49 is reversed, the control unit stops electric conduction to the electrode pair 49, and executes a reversal of polarity control reversing the polarity of the electrode pair 49 and starting the electric conduction to the electrode pair 49 after passing through a waiting step preserving electric conduction stopped state.

Description

  TECHNICAL FIELD The present invention relates to a temperature-controlled water supply device such as a heat pump water heater, a heat pump hot water heater, a combustion hot water heater, an electric water heater, a cooling tower and the like provided with an electrolyzer.

  Tap water and groundwater contain components (scale components) such as calcium ions and magnesium ions that cause scales. Therefore, in a temperature-controlled water supply device such as a water heater, scales such as calcium salt (for example, calcium carbonate) and magnesium salt may be deposited. In the water heat exchanger of the temperature-controlled water supply machine, water is heated and the temperature of the water is increased, so that scale is particularly likely to precipitate. If the scale is deposited and deposited on the inner surface of the pipe in the water heat exchanger, there may be a problem that the heat transfer performance of the water heat exchanger is lowered or the flow path of the pipe is narrowed.

  Therefore, in order to prevent scale from adhering in the water heat exchanger, a technique for removing scale components by electrolysis has been proposed. When electrolysis of tap water, groundwater, etc., scales such as calcium carbonate are deposited on the cathode side. A part of the deposited scale remains in water, while the other part adheres to the electrode (cathode) surface. The scale adhering to the electrode surface causes an increase in electrical resistance, thus reducing the removal efficiency of scale components in water. Further, when the amount of scale adhesion on the electrode surface increases, there is a possibility of causing clogging between the electrodes. The scale adhering to the electrode surface is usually dissolved and removed from the electrode surface by energizing the electrode with the polarity reversed.

Japanese Patent No. 4447148 JP 2006-027825 A

  However, there is a problem that the corrosion of the electrode is promoted when the polarity of the electrode is reversed, and if the polarity reversal is periodically performed, the electrode needs to be replaced in a short period of time.

  The objective of this invention is suppressing the corrosion of the electrode by polarity reversal in a temperature control water supply machine provided with an electrolyzer.

  (1) The temperature-controlled water feeder of the present invention comprises a water heat exchanger (21) for heating water, a container (47) having a water inlet (43) and a water outlet (45), and the container (47 ) And an electrolysis device (41) for removing scale components contained in water sent to the water heat exchanger (21), and a control unit (33). And comprising. When the polarity of the electrode pair (49) is reversed, the control unit (33) stops energization of the electrode pair (49), and after passing through a standby step in which the energization stop state is maintained, Polarity reversal control for inverting the polarity of (49) and starting energization of the electrode pair (49) is executed.

  If the polarity is reversed in the energized state, or the energization of the electrode pair is started at the same time as the polarity of the electrode pair is reversed, the electrode is easily damaged (the electrode is easily corroded). Therefore, in the present invention, when the polarity of the electrode pair (49) is reversed, the configuration in which the polarity is reversed in the energized state as in the prior art is not adopted, and the energization to the electrode pair (49) is temporarily stopped. The configuration is adopted. Thereby, damage to the electrode can be reduced (corrosion of the electrode can be suppressed), so that the life of the electrode can be extended.

  Moreover, in the present invention, the control unit (33) stops energization to the electrode pair (49), and after passing through a standby step in which the energization stop state is maintained, the polarity of the electrode pair (49) is reversed to Control for starting energization of the electrode pair (49) is executed. The reason why the polarity inversion control including such a standby step is employed is as follows.

  When the polarity is reversed, even if the energization is stopped, the potential does not immediately become zero due to the action of the electrolyte in the water. In the present invention, a standby step is adopted in order to resume energization of the electrode pair (49) in a state where the electric potential of water in the container (47) is closer to zero. Compared with the case where the polarity is reversed and energization is started, the effect of suppressing the corrosion of the electrode can be further enhanced. Specific examples of the standby step include the following control.

  (2) For example, in the standby step, the control unit (33) drains the water in the container (47), and puts the water in the container (47) again to refill the container (47). The energization stop state is maintained until the operation of replacing water is completed.

  In this control example, the water in the container (47) after replacement is simply executed by simply discharging the water in the container (47) and then putting water into the container (47) again. It becomes a state close to. And after that, since the polarity of an electrode pair (49) is reversed and electricity supply is started, corrosion of an electrode can be suppressed.

  (3) For example, the control unit (33) may maintain the energization stop state until a predetermined time elapses in the standby step.

  In this control example, when the polarity of the electrode pair (49) is reversed, the energization is not resumed until the predetermined time elapses after the energization to the electrode pair (49) is stopped. Therefore, even if the water in the container (47) is not replaced before the polarity is reversed, the potential of the water approaches zero while the predetermined time elapses. Therefore, in this control example, the effect of suppressing the corrosion of the electrode can be further enhanced as compared with the case where the polarity is reversed immediately after the energization is stopped and the energization is started.

  (4) In the case of the control example (3), it is preferable that the predetermined time is within a range of 5 minutes to 20 minutes. In this aspect, when the polarity of the electrode pair (49) is reversed, the energization to the electrode pair (49) is temporarily stopped, and after 5 minutes or more have elapsed, the polarity of the electrode pair (49) is reversed and the electrode pair (49) is reversed. Energization to (49) is started. Therefore, even if the water in the container (47) is not replaced before the polarity is reversed, the potential of the water becomes almost zero during the elapse of 5 minutes or more. Therefore, in this aspect, the effect of suppressing the corrosion of the electrode can be obtained more reliably. In addition, when the predetermined time exceeds 20 minutes, the change in the electric potential of the water cannot be expected so much thereafter. Therefore, the predetermined time is preferably set to 20 minutes or less in order to avoid waste of waiting time. .

  (5) For example, in the standby step, the control unit (33) causes water to flow into the container (47) from the water inlet (43), and causes the water in the container (47) to flow into the water outlet ( 45), the energization stop state is maintained until the operation of replacing the water in the container (47) is completed by sequentially flowing out from the water outlet (45), and the water flowing out from the water outlet (45) is transferred to the water heat exchanger (21). You may stop water supply.

  In this control example, the water in the container (47) is not temporarily discharged as in the control example in (2) above, but water is allowed to flow into the container (47) from the water inlet (43). The water in) is sequentially discharged from the water outlet (45). And if a part or all of the water in a container (47) is replaced, the electric potential of the water in a container (47) will approach zero. Thereafter, since the polarity of the electrode pair (49) is reversed and energization is started, corrosion of the electrode can be suppressed.

  As described above, according to the present invention, corrosion of the electrode due to polarity reversal can be suppressed in the temperature-controlled water supply device including the electrolyzer.

It is a lineblock diagram showing the heat pump water heater concerning one embodiment of the present invention. It is a perspective view which shows the electrolyzer used for the said heat pump water heater. (A) is sectional drawing when the said electrolyzer is cut | disconnected by the plane parallel to a perpendicular direction or a horizontal direction, and is a figure for demonstrating the control example 1 of polarity inversion control in embodiment. (B) is a figure for demonstrating the control which reverses the polarity of the electrode pair in a reference example. (A)-(D) is a figure for demonstrating the control example 2 of polarity inversion control. (A)-(C) is a figure for demonstrating the control example 2 of polarity inversion control, and has shown the step following the step shown to FIG. 4 (A)-(D). (A)-(C) is a figure for demonstrating the control example 3 of polarity inversion control. It is the schematic which shows the modification of the said electrolyzer. It is the schematic which shows the structure of the cooling tower provided with the said electrolyzer, a combustion type water heater, or an electric water heater.

  Hereinafter, a temperature-controlled water supply device (device for supplying temperature-controlled water) according to an embodiment of the present invention will be described with reference to the drawings. Examples of the temperature-controlled water supply machine include a heat pump water heater, a heat pump hot water heater, a combustion hot water heater, an electric water heater, a cooling tower, and the like. Hereinafter, the heat pump water heater will be mainly described.

<Heat pump water heater>
As shown in FIG. 1, the heat pump water heater 11 according to the present embodiment includes a refrigerant circuit 10a and a hot water storage circuit 10b. The refrigerant circuit 10a includes a compressor 19, a water heat exchanger 21, an electric expansion valve 23 as an expansion mechanism, an air heat exchanger 25, and a refrigerant pipe connecting them. The hot water storage circuit 10b includes a tank 15, a pump 31, an electrolyzer 41, a water heat exchanger 21, and water conduits 27 and 29 for connecting them. The water heat exchanger 21 has two flow paths, one flow path is connected to the refrigerant circuit 10a, and the other flow path is connected to the hot water storage circuit 10b. The operation of the refrigerant circuit 10a and the hot water storage circuit 10b is controlled by the control unit 32.

  The compressor 19, the water heat exchanger 21, the electric expansion valve 23, and the air heat exchanger 25 are provided in the heat pump unit 13. The tank 15 and the pump 31 are provided in the hot water storage unit 17. The water conduits 27 and 29 include a water inlet pipe 27 that sends water from the tank 15 to the water heat exchanger 21, and a hot water outlet pipe 29 that returns water heated by exchanging heat with the water heat exchanger 21 to the tank 15.

  The pump 31 is for sending water in the hot water storage circuit 10b. In the present embodiment, the pump 31 is provided in the incoming water pipe 27. However, the arrangement position of the pump 31 is not limited to this. By the operation of the pump 31, the water in the tank 15 flows out from the lower part of the tank 15, is sent in the order of the incoming water pipe 27, the water heat exchanger 21 and the hot water outlet 29, and returns to the upper part of the tank 15.

  In the present embodiment, carbon dioxide is used as the refrigerant circulating in the refrigerant circuit 10a, but the present invention is not limited to this. The refrigerant circulating in the refrigerant circuit 10a exchanges heat with water circulating in the hot water storage circuit 10b in the water heat exchanger 21 to heat the water, and heat exchange with outside air in the air heat exchanger 25 absorbs heat from the outside air. To do.

  A water supply pipe 37 and a hot water supply pipe 35 are connected to the tank 15. The hot water supply pipe 35 is connected to the upper part of the tank 15. The hot water supply pipe 35 is provided to take out hot water stored in the tank 15 and supply hot water to a bathtub or the like. The water supply pipe 37 is connected to the bottom of the tank 15. The water supply pipe 37 is provided to supply low-temperature water from the water supply source into the tank 15. As a water supply source for supplying water to the tank 15, for example, tap water or ground water such as well water can be used. The water heater 11 of the present embodiment is a transient water heater that does not return the hot water supplied from the hot water supply pipe 35 to the tank 15, but is not limited thereto.

  The electrolyzer 41 has a function of removing scale components contained in the water sent to the water heat exchanger 21. The electrolyzer 41 is provided at a position upstream of the water heat exchanger 21 in the water inlet pipe 27 and at a position downstream of the pump 31. Details of the electrolyzer 41 will be described later.

  The control unit 32 is configured by, for example, a microcomputer having a central processing unit 33, a memory 34, and the like. The memory 34 stores a schedule of a boiling operation (normal operation) for boiling water in the tank 15, an operation condition for polarity reversal control described later, and the like. The control unit 32 performs normal operation based on the schedule and performs polarity reversal control after the normal operation. The normal operation may be executed as necessary even at a time other than the scheduled time. It is preferable that the normal operation is scheduled to be executed, for example, at night time when the amount of water used is low, or when the electricity rate is low, but is not limited thereto.

  During normal operation, scale deposits and adheres to the surface of the electrode functioning as the cathode in the electrolysis apparatus 41. Polarity reversal control is performed to remove scale attached to the electrode surface. Details of normal operation and polarity reversal control will be described later.

  The heat pump water heater 11 of the present embodiment is a transient water heater. In the transient hot water heater 11, the water (hot water) supplied from the hot water supply pipe 35 is used by the user and does not return to the tank 15. Accordingly, the same amount of water supplied from the tank 15 through the hot water supply pipe 35 is supplied to the tank 15 from the water supply source through the water supply pipe 37. That is, the tank 15 is frequently replenished with water containing scale components from a water supply source such as tap water or well water, and the amount of replenishment is also large. Therefore, in the case of a transient heat pump water heater, it is necessary to remove scale components more efficiently than a circulating cooling water circulation device or a circulating water heater.

  Next, the operation of the heat pump water heater 11 will be described. In the normal operation of boiling water in the tank 15, the control unit 32 drives the compressor 19 of the heat pump unit 13 to adjust the opening degree of the electric expansion valve 23 and drives the pump 31 of the hot water storage unit 17. Thereby, as shown in FIG. 1, low-temperature water in the tank 15 is sent to the water heat exchanger 21 through the inlet pipe 27 from the water outlet provided at the bottom of the tank 15, and is heated in the water heat exchanger 21. The The heated high-temperature water is returned into the tank 15 from a water inlet provided in the upper part of the tank 15 through the hot water supply pipe 29. Thereby, hot water is stored in the tank 15 in order from the upper part.

<Electrolysis device>
FIG. 2 is a perspective view showing the electrolyzer 41. FIG. 3A is a cross-sectional view of the electrolyzer 41 of FIG. 2 cut along a plane parallel to the vertical direction. As shown in FIGS. 2 and 3A, the electrolyzer 41 includes a container 47 having a water inlet 43 and a water outlet 45, and a plurality of electrodes 51 and 52 accommodated in the container 47. The plurality of electrodes 51 and 52 include a plurality of first electrodes 51 and a plurality of second electrodes 52.

  The plurality of first electrodes 51 and the plurality of second electrodes 52 are arranged in one direction (electrode thickness direction) such that the first electrodes 51 and the second electrodes 52 are alternately arranged. Adjacent electrodes 51 and 52 constitute an electrode pair 49. A plurality of electrodes 51 and 52 are connected to a power source 53 so that one electrode of the electrode pair 49 functions as an anode and the other electrode functions as a cathode. As the power source 53, for example, a DC power source is used. In the present embodiment, the plurality of first electrodes 51 and the plurality of second electrodes 52 are connected in parallel to the power source 53, but are not limited thereto.

  As shown in FIG. 3A, the electrolyzer 41 includes a reversing mechanism 63 for reversing the polarity of each electrode pair 49. The reversing mechanism 63 is controlled by the control unit 32. The reversing mechanism 63 includes a contact switching unit 71 and a contact switching unit 72, and the polarity of the electrodes 51 and 52 can be reversed by switching the contact of the contact switching unit 71 and the contact switching unit 72. it can.

  Specifically, the electrode pair 49 is energized when the reversing mechanism 63 is in the state shown on the left side in FIG. In the first energization state X, the plurality of first electrodes 51 are connected to the negative electrode of the power supply 53, and the plurality of second electrodes 52 are connected to the positive electrode of the power supply 53. The electrode pair 49 is also energized when the reversing mechanism 63 is in the state shown on the right side (second energization state Z) in FIG. In the second energization state Z, the plurality of first electrodes 51 are connected to the positive electrode of the power supply 53, the plurality of second electrodes 52 are connected to the negative electrode of the power supply 53, and the polarity of the electrode pair 49 is changed from the first energization state X. Inverted. When the reversing mechanism 63 is in the state shown in the middle in FIG. 3A (energization stop state Y), the energization to the electrode pair 49 is stopped.

  Each electrode is formed of a material excellent in corrosion resistance. Examples of the material mainly constituting each electrode include platinum and titanium. Specifically, it is as follows. For example, it is preferable that at least the surface of each electrode is formed of a material whose main component is platinum. Specifically, a mode in which the entirety of each electrode is formed of a material mainly composed of platinum (a material such as platinum or a platinum alloy) can be exemplified. Each electrode is made of an electrode body made of a material having a higher ionization tendency than platinum (that is, a material that is more easily oxidized than platinum in water), and a material mainly containing platinum on the surface of the electrode body (platinum) And a coating layer formed of a material such as a platinum alloy. Examples of the material for the electrode main body include materials mainly composed of titanium (materials such as titanium and titanium alloys). In addition, each electrode may be formed of, for example, a material mainly composed of titanium (a material such as titanium or a titanium alloy) as a material that is more easily oxidized than platinum but relatively excellent in corrosion resistance. In the electrolyzer 41 that performs polarity reversal control for reversing the polarity of the electrode pair 49 as in the present embodiment, it is preferable to use the same anode material and cathode material.

  As the shape of each electrode, for example, various shapes such as a plate shape and a rod shape can be adopted, but in this embodiment, a plate shape is adopted. Thereby, the surface area of each electrode can be increased. In the present embodiment, the plurality of first electrodes 51 and the plurality of second electrodes 52 are arranged in parallel to each other, and are arranged at intervals in the thickness direction of the electrodes. The gap between the electrodes functions as a flow path through which water flows. In the present embodiment, the plurality of first electrodes 51 and the plurality of second electrodes 52 are arranged so that a meandering flow path in which water flows while meandering in the container 47 is not limited thereto.

  As shown in FIGS. 2 and 3A and 3B, the container 47 has a substantially rectangular parallelepiped shape constituted by six wall portions. These wall portions form a water flow space through which water flows. The six wall parts include a first wall part 471, a second wall part 472, a third wall part 473, a fourth wall part 474, a fifth wall part 475, and a sixth wall part 476.

  Although the water inlet 43 of the container 47 is provided in the lower part of the 1st wall part 471, and the water outlet 45 is provided in the upper part of the 2nd wall part 472, it is not limited to this. The water inlet 43 is connected to a water inlet pipe 27 located on the pump 31 (see FIG. 1) side, and the water outlet 45 is connected to a water inlet pipe 27 located on the water heat exchanger 21 side. Water sent to the electrolyzer 41 through the water inlet pipe 27 by the pump 31 flows into the water flow space inside the container 47 from the water inlet 43. The water that has flowed into the water flow space flows toward the downstream side of the water flow, and is discharged from the water outlet 45 to the outside of the container 47.

  During normal operation of boiling water in the tank 15, a voltage is applied to the electrode pair 49 of the electrolyzer 41, and a current having a predetermined current value flows. During normal operation, the scale component contained in the water is deposited as a scale on the cathodes of the electrode pair 49 until the water flowing into the container 47 from the water inlet 43 flows out of the container 47 through the water outlet 45. In normal operation, water from which the scale component has been removed in the electrolyzer 41 is sent to the water heat exchanger 21, and water is heated by exchanging heat with the refrigerant in the water heat exchanger 21. The scale adhering to the electrode surface in the normal operation is gradually removed from the electrode surface by performing polarity reversal control and then restarting the normal operation. Hereinafter, the polarity inversion control, which is a feature of this embodiment, will be described in detail.

<Polarity reversal control>
In the present embodiment, the control unit 32 stops energization of the electrode pair 49, and after passing through a standby step in which the energization stop state is maintained, reverses the polarity of the electrode pair 49 and starts energizing the electrode pair 49. Execute polarity reversal control. In other words, the polarity inversion control includes control for stopping energization to the electrode pair 49, control for maintaining the energization stop state (standby step), and inversion of the polarity of the electrode pair 49 to start energization to the electrode pair 49. Including control.

  Specific examples of polarity reversal control include control examples 1-3 described later. A feature common to each control example is that, when the polarity of the electrode pair 49 is reversed, a configuration is adopted in which energization to the electrode pair 49 is temporarily stopped. Thereby, the corrosion of the electrode resulting from polarity reversal can be suppressed.

  Another feature common to each control example is that it includes a standby step. Thereby, the corrosion of the electrode resulting from polarity reversal can be further suppressed. The reason why the corrosion inhibition effect of the electrode can be obtained by providing the standby step in the present embodiment is as follows.

  First, as described above, as described above, even when the energization is temporarily stopped, the potential does not immediately become zero due to the action of the electrolyte in water. That is, by providing a standby step, the electric potential of the water in the container 47 becomes closer to zero, so that the polarity of the electrode is reversed immediately after the energization is stopped and the electrode is corroded as compared with the case where the energization is started. The effect which suppresses can be heightened more.

  Moreover, it is estimated that the oxide film on the electrode surface is related as the second reason. That is, when the electrode pair 49 is energized during normal operation, the anode side is oxidized and the cathode side is reduced. Therefore, it is presumed that a part or all of the oxide film on the cathode surface is destroyed by energization. If the polarity of the electrode pair 49 is reversed without passing through the standby step in such an electrode state and energization is continued as it is, the electrode in which part or all of the oxide film is broken functions as an anode after the reversal. It is presumed that the anode whose oxide film is broken is oxidized by energization and promotes corrosion.

  On the other hand, in this embodiment, since a standby step is provided before the polarity of the electrode pair 49 is reversed, the electrode functioning as a cathode during energization before the standby step is partially or entirely destroyed by the oxide film. Even if it is done, the oxide film is gradually regenerated in the standby step. Therefore, it is considered that the electrode damage can be reduced by reversing the polarity of the electrode pair 49 after the standby step, and the corrosion of the electrode can be suppressed.

  In the standby step, the control unit 32 performs control for temporarily maintaining the energization stop state. In the standby step, the control unit 32 performs control to maintain the energization stop state until the standby end condition is satisfied. Hereinafter, specific contents of the polarity inversion control will be described with reference to Control Example 1-3, but the polarity inversion control is not limited to these controls.

<Control example 1>
In the control example 1, the control part 32 has a time measurement part as a function. In the standby step, the control unit 32 performs control to maintain the energization stop state until the time measured by the time measurement unit reaches a predetermined time. Specifically, it is as follows.

  FIG. 3A is a diagram for explaining a control example 1 of polarity inversion control, and FIG. 3B is a diagram for explaining a control for inverting the polarity of the electrode pair in the reference example.

  In the control example 1 shown in FIG. 3A, in the normal operation (boiling operation) for boiling water in the tank 15, the reversing mechanism 63 is set to, for example, the first energized state X in FIG. A voltage is applied to the pair 49 and a current flows. As a result, the scale component contained in the water is deposited on the cathodes of the electrode pair 49 as the scale until the water flowing into the container 47 from the water inlet 43 flows out of the container 47 from the water outlet 45.

  And the control part 32 performs polarity inversion control between a normal driving | operation and a normal driving | operation. The polarity inversion control may be executed based on, for example, a polarity inversion control schedule stored in advance in the memory 34 or the like, or may be executed as necessary based on the inversion time determination condition.

  Examples of the inversion time determination condition include conditions related to water quality such as supplied water, water in the container 47, and water discharged from the water outlet 45 of the container 47. Examples of water quality include the concentration of scale components in water. In addition, the inversion time determination condition includes, for example, a condition related to the amount of scale attached to the electrode. Examples of means for detecting the amount of scale adhesion include electrode resistance values.

  In the polarity inversion control, the control unit 32 controls the inversion mechanism 63 to change from the first energization state X to the energization stop state Y, for example. Thereby, the energization to the electrode pair 49 is stopped. And the control part 32 performs a standby step succeedingly. In the standby step of the control example 1, the energization stop state is maintained until the predetermined time (energization off time) elapses. The predetermined time is measured by a time measuring unit. The time point at which the measurement of the predetermined time is started may be, for example, the time point when the energization to the electrode pair 49 is stopped, but is not limited thereto, and may be slightly before and after the time point when the energization is stopped.

  As the predetermined time, for example, a predetermined value stored in the memory 34 is used. The predetermined time is not particularly limited because it varies depending on the quality of water supplied to the container 47, the current value during normal operation, the flow rate supplied to the container 47 during normal operation, and the like. However, if the predetermined time is 5 minutes or more, the potential of water can approach zero, and if it is 10 minutes or more, the potential of water can be made substantially zero. Therefore, the predetermined time is preferably a time within a range of 5 minutes to 20 minutes. In this case, energization to the electrode pair 49 is temporarily stopped, and after 5 minutes or more have elapsed, the polarity of the electrode pair 49 is reversed and energization to the electrode pair 49 is started. Therefore, even if the water in the container 47 is not replaced before the polarity is reversed, the potential of the water can be brought close to zero while 5 minutes or more have elapsed. Therefore, in this aspect, the effect of suppressing the corrosion of the electrode can be obtained more reliably. In addition, when the predetermined time exceeds 20 minutes, the change in the electric potential of the water cannot be expected so much thereafter. Therefore, the predetermined time is preferably set to 20 minutes or less in order to avoid waste of waiting time. .

  Further, as the predetermined time, for example, a time set in accordance with the detection result of detecting the state of water in the container 47 may be used before and / or during the execution of the polarity reversal control. Specifically, examples of the state of water to be detected include water potential and electrical conductivity.

  In the control example 1, the standby end condition of the standby step is satisfied when the time measured by the time measuring unit reaches the predetermined time. When the control unit 32 determines that the time measured by the time measurement unit has reached the predetermined time, the control unit 32 ends the standby step, reverses the polarity of the electrode pair 49, and starts energizing the electrode pair 49. That is, when the control unit 32 determines that the predetermined time has elapsed, it resumes normal operation. Specifically, the control unit 32 controls the reversing mechanism 63 to change from the energization stop state Y to the second energization state Z, for example. As a result, the polarity of the electrode pair 49 is reversed and a voltage is applied to the electrode pair 49 to start energization of the electrode pair 49.

  When the polarity is reversed from the second energization state Z to the first energization state X in the next polarity reversal control, the standby step is executed in the same manner as described above. In this standby step, the reversing mechanism 63 is set to the energization stop state Y.

  Further, in the control example 1, while the polarity inversion control is being performed, the state in which water is allowed to flow into the container 47 from the water inlet 43 and the water in the container 47 is allowed to flow out from the water outlet 45 may be maintained. In this case, water from which the scale component has not been removed in the electrolyzer 41 is sent to the water heat exchanger 21, but water heat exchange is performed by appropriately setting the predetermined time (the time during which the power is turned off). The risk of depositing scale in the vessel 21 can be reduced. In the control example 1, the inflow of water into the container 47 and the outflow of water from the container 47 may be stopped while the polarity inversion control is being executed. In this case, the above risks can be avoided.

  On the other hand, in the reference example shown in FIG. 3B, when the polarity of the electrode pair 49 is reversed in order to remove the scale attached to the electrode surface, the reversal is performed without passing through the standby step as in this embodiment. The mechanism 63 is switched from the energized state X in FIG. 3B to the energized state Z (or from the energized state Z to the energized state X). That is, in the reference example, except for a very short time required for switching the reversing mechanism 63, the polarity is reversed while the normal operation state is maintained, and the normal operation is continued.

  In the control example 1, it is not necessary to replace the water in the container 47 before the polarity is reversed, but the standby step may include a step of replacing a part of the water in the container 47, for example.

<Control example 2>
In the control example 2, the control part 32 performs control which maintains an electricity supply stop state until the replacement | exchange operation | movement of the water in the container 47 is complete | finished in a standby step. Specifically, it is as follows.

  4 (A)-(D) and FIGS. 5 (A)-(C) are diagrams for explaining a control example 2 of polarity inversion control, and FIGS. 5 (A)-(C) are FIGS. The steps following the steps shown in (A) to (D) are shown. In the control example 2, the polarity inversion control includes a plurality of steps shown in FIGS. 4A to 4D and FIGS. 5A to 5C, and is executed in this order, but is not limited thereto.

  In the control example 2, in the standby step, the control unit 32 discharges the water in the container 47 and executes the control to replace the water in the container 47 by putting the water into the container 47 again. During this time, the energization stop state is maintained. Specifically, it is as follows.

  In the electrolyzer 41 used in Control Example 2, a drain port 46 is provided at the bottom of the container 47. The drain port 46 can be opened and closed by, for example, an opening / closing valve 48, but the opening / closing mechanism is not limited to this. The on-off valve 48 is controlled by the control unit 32.

  In the control example 2, the control unit 32 performs a normal operation (boiling operation) as shown in FIG. In this normal operation, the reversing mechanism 63 is set to, for example, the energized state X and the electrode pair 49 is energized, and water is introduced into the container 47 from the water inlet 43 by the operation of the pump 31 and from the water outlet 45 to the container. 47 Water flows out to the outside. In normal operation, the drain port 46 is closed, and the container 47 is filled with water.

  Next, the control part 32 performs the polarity inversion control shown to FIG. 4 (B)-(D) and FIG. 4 (A)-(C). In the polarity inversion control, as shown in FIG. 4B, the control unit 32 switches the inversion mechanism 63 to the energization stop state Y and stops energization to the electrode pair 49. Moreover, the control part 32 stops the inflow of the water from the water inlet 43 by stopping the pump 31, and the outflow of the water from the water outlet 45 is also stopped. Next, the control unit 32 drains the water in the container 47 as shown in FIGS. 4B and 4C by opening the drain port 46. In the steps shown in FIGS. 4B and 4C, the reversing mechanism 63 is maintained in the energization stopped state.

  When the drainage of water is completed, the control unit 32 closes the drain outlet 46 as shown in FIG. Next, the control unit 32 operates the pump 31 as shown in FIGS. 5A and 5B to cause water to flow into the container 47 from the water inlet 43. In the steps shown in FIGS. 5A and 5B, the reversing mechanism 63 is maintained in the energization stopped state.

  When the container 47 is filled with water, the control unit 32 ends the standby step, and switches the reversing mechanism 63 to the energized state Z as shown in FIG. 5C to reverse the polarity of the electrode pair 49. Then, energization of the electrode pair 49 is started. That is, when the container 47 is filled with water, the control unit 32 ends the standby step and resumes normal operation. In normal operation, water flows into the container 47 from the water inlet 43, and water sequentially flows out of the container 47 from the water outlet 45. Then, the scale component contained in the water is deposited as a scale on the cathodes of the electrode pair 49 until the water flowing into the container 47 from the water inlet 43 flows out of the container 47 from the water outlet 45.

<Control example 3>
In the control example 3, the control unit 32 performs the control to maintain the energization stop state in the standby step until the operation of replacing the water in the container 47 is completed as in the control example 2. Specifically, it is as follows.

  6A to 6C are diagrams for explaining a control example 3 of the polarity inversion control. In the control example 3, the polarity inversion control includes a plurality of steps of FIGS. 6A to 6C and is executed in this order, but is not limited to this.

  In the control example 3, in the standby step, the control unit 32 controls the replacement of the water in the container 47 by causing the water to flow into the container 47 from the water inlet 43 and the water in the container 47 to flow out from the water outlet 45 sequentially. During the operation, the energization stop state is maintained, and the water supply from the water outlet 45 to the water heat exchanger 21 is stopped. Specifically, it is as follows.

  In the electrolysis apparatus 41 used in the control example 3, a drainage channel 44 is provided between the water outlet 45 of the container 47 and the hydrothermal exchanger 21 as shown in FIGS. 6 (A) to (C). . The drainage channel 44 can be opened and closed by a switching mechanism 42. The switching mechanism 42 is controlled by the control unit 32. Examples of the switching mechanism 42 include a switching valve provided at a branch portion between the drainage channel 44 and the water inlet pipe 27. Examples of the switching mechanism 42 include open / close valves provided in each of the drainage channel 44 and the water inlet pipe 27.

  In FIGS. 6A to 6C, the drainage channel 44 is provided in the vicinity of the water outlet 45, but is not limited thereto. For example, the drainage channel 44 may be provided in the vicinity of the water heat exchanger 21, or may be provided in an intermediate portion between the water outlet 45 and the water heat exchanger 21.

  In the control example 3, the control unit 32 performs a normal operation (boiling operation) as shown in FIG. In this normal operation, the reversing mechanism 63 is set to, for example, the energized state X and the electrode pair 49 is energized, and water is introduced into the container 47 from the water inlet 43 by the operation of the pump 31 and from the water outlet 45 to the container. 47 Water flows out to the outside. In normal operation, the drainage channel 44 is closed, and the container 47 is filled with water.

  Next, the control unit 32 performs polarity inversion control shown in FIGS. In the polarity inversion control, as shown in FIG. 6B, the control unit 32 switches the inversion mechanism 63 to the energization stop state Y and stops energization to the electrode pair 49. Moreover, the control part 32 makes the drainage channel 44 open while continuing the operation of the pump 31, whereby the water flowing out from the water outlet 45 is drained through the drainage channel 44. Thereby, it is possible to prevent water flowing out from the water outlet 45 from flowing into the water heat exchanger 21.

  In the control example 3, the end time of the standby step in FIG. 6B is determined based on a predetermined standby end condition. Examples of the standby end condition include conditions based on time, amount of drainage, water state, and the like. Specifically, when it is determined that the elapsed time from the start of the standby step has reached a predetermined reference value, the control unit 32 ends the standby step. In addition, the control unit 32 may end the standby step when determining that the amount of water drained from the drainage channel 44 has reached a predetermined reference value in the standby step. Moreover, the control part 32 may complete | finish a standby step, when it is judged that the state of water in the standby step (for example, the electric potential of water, electrical conductivity, etc.) has reached a predetermined reference value.

  When the control unit 32 determines that the standby end condition is satisfied, the control unit 32 ends the standby step, switches the reversing mechanism 63 to the energized state Z as shown in FIG. 6C, and reverses the polarity of the electrode pair 49. Then, energization of the electrode pair 49 is started. That is, when the predetermined condition is satisfied, the control unit 32 ends the standby step and resumes normal operation. In normal operation, water flows into the container 47 from the water inlet 43, and water sequentially flows out of the container 47 from the water outlet 45. Then, the scale component contained in the water is deposited as a scale on the cathodes of the electrode pair 49 until the water flowing into the container 47 from the water inlet 43 flows out of the container 47 from the water outlet 45.

<Modification>
The electrolyzer 41 is not necessarily limited to the case of having a meandering flow path as shown in FIG. 3A, and may be an electrolyzer 41 such as the modification shown in FIG. As shown in FIG. 7, the electrolyzer 41 includes a container 47 having a water inlet 43 and a water outlet 45, and a first electrode 51 and a second electrode 52 accommodated in the container 47. Since this electrolyzer 41 does not have a meandering flow path, the water flowing into the container 47 from the water inlet 43 flows in the container 47 from the water inlet 43 toward the water outlet 45 at random to some extent, The scale component is removed in the process of passing through the gap between adjacent electrodes in the middle of flowing toward the 45 side. Also in this modification, the above-described normal operation and polarity inversion control are executed. In the modification, the reversing mechanism 63, the drain port 46, the drain channel 44, and the like are not shown. Also in this modified example, polarity inversion control like the control example 1-3 described above is executed.

  As described above, in the present embodiment, when the polarity of the electrode pair 49 is reversed, the control unit 32 stops energization to the electrode pair 49 and passes through a standby step in which the energization stop state is maintained, and then the electrode Polarity reversal control for inverting the polarity of the pair 49 and starting energization of the electrode pair 49 is executed. If the polarity of the electrode pair is reversed and energization to the electrode pair is started at the same time, the electrode is easily damaged. Therefore, in the present embodiment, when the polarity of the electrode pair 49 is reversed, the configuration in which the polarity is reversed in the energized state as in the reference example is not adopted, and the configuration in which the energization to the electrode pair 49 is temporarily stopped. Adopted. Thereby, damage to an electrode can be reduced.

  Moreover, in the present embodiment, the control unit 32 stops energization of the electrode pair 49, and after passing through a standby step in which the energization stop state is maintained, the polarity of the electrode pair 49 is reversed to energize the electrode pair 49. Execute the control to start. Thereby, the effect which suppresses corrosion of an electrode can be heightened more compared with the case where polarity is reversed immediately after energization stop and energization is started.

  Therefore, the temperature-controlled water supply device according to the present embodiment is particularly effective when water with a large scale tendency is used. That is, when the scale component concentration in the water supplied to the container 47 of the electrolyzer 41 is high, the amount of scale attached to the electrode (cathode) during the boiling operation (during normal operation) increases. The number of removal of the attached scale is also increased. Specifically, when the amount of scale adhesion during the boiling operation increases, for example, there is a possibility that scale removal may be required once or a plurality of times during the boiling operation. In this case, if the temperature-regulated water supply device according to the present embodiment is employed, corrosion of the electrode can be suppressed even if the frequency of polarity reversal control is high, and the amount of scale attached to the electrode can be appropriately managed. It can suppress that scale removal efficiency falls.

  In the control example 1, in the standby step, the control unit 32 maintains the energization stop state until a predetermined time elapses. In this control example 1, when the polarity of the electrode pair 49 is reversed, the energization is not resumed until the predetermined time elapses after the energization to the electrode pair 49 is stopped. Therefore, even if the water in the container 47 is not replaced before the polarity is reversed, the potential of the water approaches zero while the predetermined time elapses. Therefore, in this control example 1, the effect of suppressing the corrosion of the electrode can be further enhanced as compared with the case where the polarity is reversed immediately after the energization is stopped and the energization is started.

  In the control example 2, in the standby step, the control unit 32 discharges the water in the container 47 and puts the energization stopped state while executing the control to replace the water in the container 47 by putting water into the container 47 again. maintain. In this control example 2, the water in the container 47 after replacement is brought to a state close to zero simply by executing a simple operation of once draining the water in the container 47 and refilling the container 47 with water. . Then, since the polarity of the electrode pair 49 is reversed and energization is started, corrosion of the electrode can be suppressed.

  In the control example 3, in the standby step, the control unit 32 controls the replacement of the water in the container 47 by causing the water to flow into the container 47 from the water inlet 43 and the water in the container 47 to flow out from the water outlet 45 sequentially. During the operation, the energization stop state is maintained, and the water supply from the water outlet 45 to the water heat exchanger 21 is stopped.

  In this control example 3, the water in the container 47 is not temporarily discharged as in the control example 2, but the water is allowed to flow into the container 47 from the water inlet 43 and the water in the container 47 sequentially flows out from the water outlet 45. Let And if a part or all of the water in the container 47 is replaced, the water in the container 47 has a potential closer to zero. Thereafter, since the polarity of the electrode pair 49 is reversed and energization is started, corrosion of the electrode can be suppressed.

  In the control examples 2 and 3, since the water discharged from the container 47 is not sent to the water heat exchanger 21, the time for completing the boiling operation of the heat pump water heater is delayed by the time required for the polarity inversion control. On the other hand, in the control examples 2 and 3, since the water in the container 47 is switched, the effect of suppressing the corrosion of the electrode is the control example 1 (while the polarity reversal control is being performed, the water is introduced into the container 47 from the water inlet 43. Is larger than the control example 1) in the case where the state in which the water in the container 47 is flowed out from the water outlet 45 is maintained.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention.

  In the above embodiment, the case where the plurality of electrodes 51 and 52 form a meandering flow path that meanders in the vertical direction in the container 47 is exemplified, but the present invention is not limited to this. For example, the form which forms the meandering flow path in which the some electrodes 51 and 52 meander in other directions, such as a horizontal direction, in the container 47 may be sufficient. In order to obtain a meandering flow path meandering in the horizontal direction, for example, in the electrolysis apparatus 41 shown in FIGS. 3A and 3B, the fifth wall portion 475 is located below and the sixth wall portion 476 is located above. What is necessary is just to arrange | position so that it may be located in.

  In the said embodiment, the case where the electrolyzer 41 is provided in the inflow piping 27 located downstream from the pump 31 and upstream from the water heat exchanger 21 in the water flow path of the heat pump water heater 11 is given as an example. However, the present invention is not limited to this. The electrolyzer 41 may be provided upstream of the water heat exchanger 21 in the water flow path. Specifically, the electrolyzer 41 may be provided, for example, in the incoming water pipe 27 upstream of the pump 31, or may be provided in the water supply pipe 37 that supplies water to the tank 15 from the water supply source. Good.

  In the embodiment, the case where the container 47 has a substantially rectangular parallelepiped shape has been described as an example. However, the present invention is not limited to this. The container 47 may have a prismatic shape other than a rectangular parallelepiped or a cylindrical shape.

  Moreover, in the said embodiment, although the transient hot water heater was mentioned as an example and demonstrated, it is not limited to this. The present invention can also be applied to, for example, a water heater of a type in which a part of water (hot water) supplied from the hot water supply pipe 35 is returned to the tank 15 again.

  Moreover, in the said embodiment, although the case where the temperature control water supply machine was the heat pump water heater 11 was illustrated, it is not limited to this. As a temperature control water supply machine, it is applicable also to the other use which needs to remove a scale component, for example, a heat pump hot water heater, a combustion type hot water heater, an electric water heater, a cooling tower, etc.

  In the heat pump hot water heater, for example, in the configuration diagram shown in FIG. 1, high-temperature water stored in the tank 15 is used for heating and the like.

  As shown in FIG. 8, the combustion-type water heater includes an electrolyzer 41 and a water heat exchanger 21 </ b> A provided on the downstream side of the electrolyzer 41. In the combustion type water heater, water is heated using thermal energy obtained by burning fuel gas or the like in the water heat exchanger 21A.

  Further, as shown in FIG. 8, the electric water heater includes an electrolysis device 41 and a water heat exchanger 21 </ b> A provided on the downstream side of the electrolysis device 41. In the electric water heater, water is heated using electric energy in the water heat exchanger 21A.

  For example, as shown in FIG. 8, the cooling tower includes an electrolyzer 41 and a water heat exchanger 21 </ b> A provided on the downstream side of the electrolyzer 41. In the cooling tower, water is heated in the water heat exchanger 21A by exchanging heat generated by other devices with a fluid that has been conveyed.

DESCRIPTION OF SYMBOLS 11 Heat pump water heater 15 Tank 19 Compressor 21 Water heat exchanger 27 Inlet piping 29 Outlet piping 31 Pump 32 Control part 41 Electrolyzer 43 Water inlet 44 Drainage channel 45 Water outlet 46 Drainage port 47 Container 49 Electrode pair 63 Inversion mechanism X Energized state Y Energized stop state Z Energized state

Claims (5)

A water heat exchanger (21) for heating the water;
It has a container (47) having a water inlet (43) and a water outlet (45) and an electrode pair (49) provided in the container (47), and supplies water to the water heat exchanger (21). An electrolyzer (41) for removing the contained scale components;
A control unit (33),
When the polarity of the electrode pair (49) is reversed, the control unit (33) stops energization of the electrode pair (49), and after passing through a standby step in which the energization stop state is maintained, A temperature-regulated water supply machine that performs polarity reversal control that reverses the polarity of (49) and starts energization of the electrode pair (49).   In the standby step, the controller (33) discharges water in the container (47), and replaces the water in the container (47) by putting water into the container (47) again. The temperature-controlled water supply machine according to claim 1, wherein the energization stop state is maintained until the end.   The said control part (33) is a temperature control water supply machine of Claim 1 which maintains an electricity supply stop state until the predetermined time passes in the said waiting | standby step.   The temperature-controlled water supply machine according to claim 3, wherein the predetermined time is a time within a range of 5 minutes to 20 minutes. In the standby step, the controller (33) allows water to flow into the container (47) from the water inlet (43), and sequentially discharges the water in the container (47) from the water outlet (45). By doing so, the energization stop state is maintained until the operation of replacing the water in the container (47) is completed, and the water supply to the water heat exchanger (21) flowing out of the water outlet (45) is stopped. The temperature-controlled water supply machine according to claim 1.

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