U.S. patent application number 13/823912 was filed with the patent office on 2013-07-18 for electrolysis device and heat-pump-type water heater provided with same.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. The applicant listed for this patent is Isao Fujinami, Yutaka Shibata, Kaori Yoshida. Invention is credited to Isao Fujinami, Yutaka Shibata, Kaori Yoshida.
Application Number | 20130180846 13/823912 |
Document ID | / |
Family ID | 45892356 |
Filed Date | 2013-07-18 |
United States Patent
Application |
20130180846 |
Kind Code |
A1 |
Shibata; Yutaka ; et
al. |
July 18, 2013 |
ELECTROLYSIS DEVICE AND HEAT-PUMP-TYPE WATER HEATER PROVIDED WITH
SAME
Abstract
An electrolysis device includes: a container including a first
circulation port functioning as one of an inlet and an outlet for
water, and a second circulation port functioning as the other of
the inlet and the outlet for water; a plurality of electrode pairs
disposed in the container; and a power supply configured to apply a
voltage to each of the electrode pairs. Each of the electrode pairs
includes a pair of electrode plates. A plurality of the electrode
plates are arrayed spaced apart from one another in the thickness
direction of the electrode plate. In the electrolysis device, a
water channel is formed by the plurality of electrode plates such
that water flowing from the inlet into the container reaches the
outlet after passing between the pair of electrode plates in each
of the electrode pairs.
Inventors: |
Shibata; Yutaka; (Sakai-shi,
JP) ; Yoshida; Kaori; (Sakai-shi, JP) ;
Fujinami; Isao; (Sakai-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shibata; Yutaka
Yoshida; Kaori
Fujinami; Isao |
Sakai-shi
Sakai-shi
Sakai-shi |
|
JP
JP
JP |
|
|
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
|
Family ID: |
45892356 |
Appl. No.: |
13/823912 |
Filed: |
September 28, 2011 |
PCT Filed: |
September 28, 2011 |
PCT NO: |
PCT/JP11/05464 |
371 Date: |
March 15, 2013 |
Current U.S.
Class: |
204/196.02 ;
204/196.37 |
Current CPC
Class: |
C02F 2201/4611 20130101;
C02F 1/46104 20130101; F24D 19/0092 20130101; F24H 9/0047 20130101;
C02F 2209/005 20130101; C02F 2301/028 20130101; C02F 2201/46135
20130101; F24D 17/02 20130101; C02F 1/4602 20130101; F24H 9/0015
20130101; F24H 4/04 20130101 |
Class at
Publication: |
204/196.02 ;
204/196.37 |
International
Class: |
F24H 9/00 20060101
F24H009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2010 |
JP |
2010-220944 |
Claims
1. An electrolysis device used in a water heater including a water
heat exchanger for heating water, the electrolysis device
comprising: a container including a first flow port functioning as
one of an inlet and an outlet for water, and a second flow port
functioning as the other of the inlet and the outlet for water; a
plurality of electrode pairs disposed in the container; and a power
supply configured to apply a voltage to each of the electrode
pairs, wherein each of the electrode pairs includes a pair of
electrode plates, a plurality of the electrode plates are arrayed
spaced apart from one another in a thickness direction of the
electrode plate, and a water channel is formed by the plurality of
electrode plates such that water flowing from the inlet into the
container reaches the outlet after passing between the pair of
electrode plates in each of the electrode pairs.
2. The electrolysis device according to claim 1, wherein the
container includes: a first wall located on one side in an array
direction of the plurality of electrode plates; a second wall
located on the other side in the array direction and opposed to the
first wall across the plurality of electrode plates; and a sidewall
that extends along the array direction to surround the plurality of
electrode plates and connects the first wall and the second wall,
and the first flow port is provided in the first wall or in the
vicinity of the first wall, and the second flow port is provided in
the second wall or in the vicinity of the second wall.
3. The electrolysis device according to claim 2, wherein the
sidewall includes a third wall extending along the array direction,
and a fourth wall extending along the array direction and opposed
to the third wall across the plurality of electrode plates, the
plurality of electrode plates include first electrode plates
connected to one pole of the power supply and second electrode
plates connected to the other pole of the power supply, each of the
first electrode plates is extended from a proximal end portion of
the first electrode plate located in the third wall toward the
fourth wall, each of the second electrode plates is extended from a
proximal end portion of the second electrode plate located in the
fourth wall toward the third wall, and the first electrode plates
and the second electrode plates are alternately arranged along the
array direction, whereby the water channel includes a serpentine
flow path.
4. The electrolysis device according to claim 2, wherein the
sidewall includes a third wall extending along the array direction,
and a fourth wall extending along the array direction and opposed
to the third wall across the plurality of electrode plates, a gap
through which the water can pass is provided between one end
portion of each of the electrode plates and the third wall, and a
gap through which the water can pass is provided between the other
end portion of each of the electrode plates and the fourth wall,
and the first flow port is provided in the first wall in a position
closer to the third wall than the fourth wall, and the second flow
port is provided in the second wall in a position closer to the
fourth wall than the third wall.
5. The electrolysis device according to claim 4, wherein each of
the electrode plates are arranged to incline such that the one end
portion is located on the one side in the array direction than the
other end portion.
6. A heat-pump-type water heater comprising: a heat pump unit which
includes a water heat exchanger for heating water, and in which a
refrigerant circulates through a refrigerant pipe; a hot water
storage unit including a tank in which the water is stored, a feed
channel for feeding the water in the tank to the water heat
exchanger, and a return channel for returning the water heated by
the water heat exchanger to the tank; a water supply pipe for
supplying the water from a water supply source to the tank; a hot
water supply pipe for supplying high-temperature water stored in
the tank; and the electrolysis device according to claim 1 for
removing scale components contained in the water.
7. The heat-pump-type water heater according to claim 6, wherein
the electrolysis device is provided in the feed channel.
8. The heat-pump-type water heater according to claim 6, further
comprising a control unit configured to control the power supply
for the electrolysis device, wherein the control unit controls the
power supply such that a voltage is applied to each of the
electrode pairs when temperature of water heated by the water heat
exchanger is equal to or higher than a value set in advance.
9. The heat-pump-type water heater according to claim 6, further
comprising a control unit configured to control the power supply
for the electrolysis device, wherein the control unit controls the
power supply to adjust a voltage applied to each of the electrode
pairs according to water quality in the hot water storage unit.
10. The heat-pump-type water heater according to claim 6, further
comprising a re-inflow channel for returning water having passed
through the electrolysis device to an upstream side of the
electrolysis device and causing the water to flow into the
electrolysis device again.
11. The heat-pump-type water heater according to claim 6, further
comprising a reversing mechanism for changing the inlet and the
outlet in the electrolysis device.
12. The heat-pump-type water heater according to claim 6, wherein
the heat-pump-type water heater is of one-through type that does
not return, to the tank, hot water supplied from the hot water
supply pipe.
Description
TECHNICAL FIELD
[0001] The present invention relates to an electrolysis device for
removing, in a water heater such as a heat-pump-type water heater,
scale components in water, and to a heat-pump-type water heater
provided with the electrolysis device.
BACKGROUND ART
[0002] In general, a heat-pump-type water heater includes a heat
pump unit in which a compressor, a water heat exchanger, an
expansion valve, and an air heat exchanger are connected by pipes
in this order; and a hot water storage unit including a tank in
which water is stored, an inflow water pipe for feeding the water
in the tank to the water heat exchanger, and an outflow hot water
pipe for returning the water heated by the water heat exchanger to
the tank. In the heat-pump-type water heater, usually, a water
supply source of the water stored in the tank is tap water, well
water, or the like.
[0003] Incidentally, the tap water or the well water contains
components such as calcium ion, magnesium ion, and the like that
cause scale (hereinafter referred to as scale components).
Therefore, in a water heater, scale of calcium salt, magnesium
salt, and the like is precipitated. In particular, underground
water such as the well water has high concentration of the scale
components compared with the tap water and has water quality that
tends to cause scale. In the water heat exchanger, since the
temperature of the water is high, scale is more likely to be
precipitated than in other regions. When scale is precipitated and
deposited on the inner surface of a pipe of the water heat
exchanger, a problem occurs in that, for example, the heat transfer
performance of the water heat exchanger is deteriorated or a
channel of the pipe is narrowed.
[0004] For example, Patent Document 1 proposes a cooling water
circulating apparatus including an electrolysis device in which one
electrode pair is set in an electrolytic cell. Patent Document 1
describes that, since scale components can be removed from cooling
water through electrolysis, it is possible to reduce adhesion of
scale in a circulating path.
[0005] However, in the electrolysis device disclosed in Patent
Document 1, removal efficiency for scale components in water is not
necessarily sufficient.
[0006] Patent Document 1: WO2006/027825
SUMMARY OF THE INVENTION
[0007] Therefore, the present invention has been devised in view of
such a point and it is an object of the present invention to
provide an electrolysis device that excels in removal efficiency
for scale components and a heat-pump-type water heater provided
with the electrolysis device.
[0008] The electrolysis device (41) according to the present
invention is used in a water heater including a water heat
exchanger (21) for heating water. The electrolysis device (41)
includes a container (47), a plurality of electrode pairs (49), and
a power supply (51). The container (47) includes a first flow port
(43) functioning as one of an inlet and an outlet for water, and a
second flow port (45) functioning as the other of the inlet and the
outlet for water. The plurality of electrode pairs (49) are
disposed in the container (47). The power supply (51) applies a
voltage to each of the electrode pairs (49). Each of the electrode
pairs (49) includes a pair of electrode plates (53). A plurality of
the electrode plates (53) are arrayed spaced apart from one another
in the thickness direction of the electrode plate (53). In the
electrolysis device (41), a water channel (F) is formed by the
plurality of electrode plates (53) such that water flowing into the
container (47) from the inlet reaches the outlet after passing
between the pair of electrode plates (53) in each of the electrode
pairs (49).
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a configuration diagram showing a heat-pump-type
water heater according to an embodiment of the present
invention.
[0010] FIG. 2A is a sectional view showing an electrolysis device
according to a first embodiment of the present invention used in
the heat-pump-type water heater and is a diagram of the
electrolysis device viewed from a side. FIG. 2B is a plan view of
the electrolysis device.
[0011] FIG. 3A is a schematic diagram showing the electrolysis
device shown in FIG. 2. FIGS. 3B to 3D are schematic diagrams
respectively showing electrolysis devices according to
modifications of the first embodiment.
[0012] FIGS. 4A to 4D are schematic diagrams respectively showing
electrolysis devices according to other modifications of the first
embodiment.
[0013] FIGS. 5A to 5D are schematic diagrams respectively showing
electrolysis devices according to still other modifications of the
first embodiment.
[0014] FIG. 6 is a sectional view showing an electrolysis device
according to a second embodiment of the present invention.
[0015] FIG. 7A is a schematic diagram showing the electrolysis
device shown in FIG. 6. FIGS. 7B to 7D are schematic diagrams
showing electrolysis devices according to modifications of the
second embodiment.
[0016] FIGS. 8A to 8H are schematic diagrams showing electrolysis
devices according to other modifications of the second
embodiment.
[0017] FIGS. 9A to 9C are sectional views showing an electrolysis
device according to still another modification of the second
embodiment.
[0018] FIG. 10 is a sectional view showing a modification of the
heat-pump-type water heater.
[0019] FIGS. 11A and 11B are schematic diagrams showing
modifications of the heat-pump-type water heater.
[0020] FIG. 12 is a schematic diagram showing a modification of the
heat-pump-type water heater.
[0021] FIGS. 13A and 13B are schematic diagrams showing
modifications of the heat-pump-type water heater.
DESCRIPTION OF EMBODIMENTS
[0022] Embodiments of the present invention are explained in detail
below with reference to the drawings.
[0023] <Heat-Pump-Type Water Heater>
[0024] As shown in FIG. 1, a heat-pump-type water heater 11 of a
first embodiment includes a heat pump unit 13 in which a
refrigerant circulates, a hot water storage unit 17 that exchanges
heat with the refrigerant in the heat pump unit 13 to heat up
low-temperature water and stores high-temperature water in a tank
15, a water supply pipe 37, a hot water supply pipe 35, an
electrolysis device 41, and a control unit 33.
[0025] The heat pump unit 13 includes a compressor 19, a water heat
exchanger 21, an electric expansion valve 23, an air heat exchanger
25, and pipes that connect the foregoing. In this embodiment,
carbon dioxide is used as the refrigerant circulating in the heat
pump unit 13. The refrigerant exchanges, in the water heat
exchanger 21, heat with the water circulating in the hot water
storage unit 17 to heat the water and exchanges, in the air heat
exchanger 25, heat with the outside air to absorb heat from the
outside air.
[0026] The hot water storage unit 17 includes the tank 15 in which
water is stored, an inflow water pipe 27 for feeding the water in
the tank 15 to the water heat exchanger 21, and an outflow hot
water pipe 29 for returning the water heated by heat exchange with
the water heat exchanger 21 to the tank 15. A pump 31 is provided
in the inflow water pipe 27. The pump 31 feeds the water flowing
into the inflow water pipe 27 from a lower part of the tank 15 to
the water heat exchanger 21 and further feeds the water to an upper
part of the tank 15 through the outflow hot water pipe 29.
[0027] The electrolysis device 41 is provided in the inflow water
pipe 27 and located between the pump 31 and the water heat
exchanger 21. Details of the electrolysis device 41 are explained
below.
[0028] The hot water supply pipe 35 is connected to the upper part
of the tank 15. The hot water supply pipe 35 is a pipe for
extracting high-temperature water stored in the tank 15 and
supplying the high-temperature 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 a pipe for supplying low-temperature water
into the tank 15 from a water supply source. As the water supply
source for supplying water to the tank 15, for example, tap water
or underground water such as well water can be used.
[0029] The control unit 33 is configured by, for example, a central
processing unit (CPU), a memory in which data such as a program is
stored, and a memory for storing data during program execution,
various setting values, measured data, and the like. The control
unit 33 controls the heat pump unit 13 and the hot water storage
unit 17 on the basis of temperature data and the like measured by
not-shown temperature sensors provided in the tank 15, the water
heat exchanger 21, the pipes, and the like.
[0030] The operation of the water heater 11 is explained. In a
heat-up operation for heating up water in the tank 15, the control
unit 33 drives the compressor 19 of the heat pump unit 13, adjusts
an opening degree of the electric expansion valve 23, and drives
the pump 31 of the hot water storage unit 17. Consequently, as
shown in FIG. 1, low-temperature water in the tank 15 is fed from
an outflow water port provide in the bottom of the tank 15 to the
water heat exchanger 21 through the inflow water pipe 27 and heated
in the water heat exchanger 21. Heated high-temperature water is
returned into the tank 15 from an inflow water port provided in the
upper part of the tank 15 through the outflow hot water pipe 29.
Consequently, the high-temperature water is stored in the tank 15
from the top of the tank 15 in order.
[0031] The heat-pump-type water heater 11 according to this
embodiment is of one-through type water heater. In the one-through
type water heater 11, water (hot water) supplied from the hot water
supply pipe 35 is used by a user and is not returned to the tank
15. Therefore, water of substantially the same amount as an amount
of water supplied from the tank 15 through the hot water supply
pipe 35 is supplied from the water supply source to the tank 15
through the water supply pipe 37. That is, water containing scale
components is frequently supplied to the tank 15 from the water
supply source such as the tap water or the well water. An amount of
the supplied water is large. Therefore, in the case of the
one-through heat-pump-type water heater, it is necessary to
efficiently remove the scale components compare with the cooling
water circulating apparatus of a circulation type and a water
heater of a circulation type.
[0032] <Electrolysis Device>
First Embodiment
[0033] FIG. 2A is a sectional view showing the electrolysis device
41 according to a first embodiment of the present invention used in
the water heater 11. FIG. 2A is a diagram of the electrolysis
device 41 viewed from a side. FIG. 2B is a plan view of the
electrolysis device 41. As shown in FIGS. 2A and 2B, the
electrolysis device 41 according to the first embodiment includes a
container 47, a plurality of electrode pairs 49, and power supplies
51.
[0034] As shown in FIGS. 2A and 2B, the container 47 has a
substantially rectangular parallelepiped shape. The container 47
includes a first wall 471 located on an upstream side of a flow of
water, and a second wall 472 located on a downstream side and a
sidewall 48 that connects the walls 471 and 472. The first wall 471
and the second wall 472 are opposed to each other across a
plurality of electrode plates 53 explained below in a direction in
which the sidewall 48 extends (an array direction D of the
plurality of electrode plates 53).
[0035] The sidewall 48 includes a third wall 473 and a fourth wall
474 shown in FIG. 2A and a fifth wall 475 and a sixth wall 476
shown in FIG. 2B. The electrolysis device 41 according to this
embodiment is used while being arranged in a posture shown in FIG.
2A such that, for example, the third wall 473 is located below and
the fourth wall 474 is located above. The third wall 473 and the
fourth wall 474 are opposed to each other in a height direction H
(the up down direction) across the plurality of electrode plates
53. Similarly, the fifth wall 475 and the sixth wall 476 are
opposed to each other in a width direction W (the horizontal
direction perpendicular to the array direction D) across the
plurality of electrode plates 53.
[0036] The first wall 471 includes a first flow port 43 functioning
as an outlet and inlet for water. The second wall 472 includes a
second flow port 45 functioning as an outlet and inlet for water.
In this embodiment, the first flow port 43 functions as an inlet
and the second flow port 45 functions as an outlet. Inflow water
pipes 27 are respectively connected to the first flow port 43 and
the second flow port 45.
[0037] The first flow port 43 is provided in the first wall 471 in
a position closer to the third wall 473 than the fourth wall 474
and closer to the fifth wall 475 than the sixth wall 476. The
second flow port 45 is provided in the second wall 472 in a
position closer to the fourth wall 474 than the third wall 473 and
closer to the sixth wall 476 than the fifth wall 475. Specifically,
the first flow port 43 and the second flow port 45 are respectively
provided in the vicinities of opposite angles in the container 47
having a rectangular parallelepiped shape.
[0038] The container 47 has an elongated shape. A distance between
the outer surface of the first wall 471 and the outer surface of
the second wall 472 is larger than a distance between the outer
surface of the third wall 473 and the outer surface of the fourth
wall 474 and a distance between the outer surface of the fifth wall
475 and the outer surface of the sixth wall 476.
[0039] Each of the electrode pairs 49 is configured by a pair of
electrode plates 53 (a first electrode plate 531 and a second
electrode plate 532). The plurality of electrode plates 53
configuring the plurality of electrode pairs 49 are arranged in the
container 47. The plurality of electrode plates 53 are arrayed
spaced apart from one another in the thickness direction of the
electrode plates 53. Each of the electrode plates 53 is arranged in
a posture extending in a direction substantially perpendicular to
the array direction D. The array direction D generally coincides
with the direction in which the sidewall 48 extends (the
longitudinal direction of the container 47). A space between the
electrode plates 53 of each of the electrode pairs 49 is
substantially the same. A gap between the electrode plates 53 in
each of the electrode pairs 49 functions as a channel (a water
channel) F through which water flows.
[0040] Each of the electrode plates 53 has a substantially
rectangular shape. Examples of the material of the electrode plate
53 include titanium, platinum, nickel, carbon, graphite, copper,
and vitreous carbon.
[0041] The plurality of electrode plates 53 include a plurality of
first electrode plates 531 connected to positive poles of the power
supplies 51 and a plurality of second electrode plates 532
connected to negative poles of the power supplies 51. In this
embodiment, the first electrode plates 53 function as anodes and
the second electrode plates 532 function as cathodes. The first
electrode plates 531 and the second electrode plates 532 are
alternately arranged along the array direction D of the plurality
of electrode plates 53. Each of the electrode plates 53 is
insulated from the electrode plate 53 of opposite pole, and is
fixed to the side wall 48 by, for example, a supporting member
which is not shown.
[0042] For example, in FIG. 2A, the second electrode plate 532 at
the left end and the first electrode plate 531 second from the left
configure one electrode pair 49. The first electrode plate 531
second from the left and the second electrode plate 532 third from
the left configure one electrode pair 49. Similarly, the electrode
plates 53 adjacent to each other configure one electrode pair
49.
[0043] A gap G1 through which water can pass is provided between
one end portion 53a in the height direction H in each of the
electrode plates 53 and the inner surface of the third wall 473. A
gap G2 through which water can pass provided between the other end
portion 53b in the height direction H in each of the electrode
plates 53 and the inner surface of the fourth wall 474. Gaps
between each of the electrode plates 53 and inner surface of the
side wall 48 may be only the gap G1 and the gap G2. However, gaps
may be further provided between the end portion of each of the
electrode plates 53 and the inner surface of the fifth wall 475 and
between the end portion of each of the electrode plates 53 and the
inner surface of the sixth wall 476.
[0044] In the electrolysis device 41 having the structure explained
above, water flowing into the container 47 from the first flow port
43 flows out to the outside of the container 47 from the second
flow port 45 roughly through a path explained below. That is, the
water flowing into the container 47 flows to the second wall 472
side along the third wall 473 through the gap G1 between the one
end portion 53a of each of the electrode plates 53 and the inner
surface of the third wall 473. A part of the water flowing along
the third wall 473 flows into a gap (the water channel F) between
the electrode plates 53 of each of the electrode pairs 49, which
are arranged in the array direction D, in order from the water
channel F on the upstream side. The water flowing along the
electrode plates 53 through the water channel F of each of the
electrode pairs 49 merges on the fourth wall 474 side, flows to the
second wall 472 side along the fourth wall 474, and flows out to
the outside of the container 47 from the second flow port 45.
[0045] Until the water flowing into the container 47 from the first
flow port 43 flows out to the outside of the container 47 from the
second flow port 45, scale is precipitated by the electrolysis on
the second electrode plate 532, which is the cathode. The scale
adhering to the second electrode plate 532 is removed from the
inside of the electrolysis device 41 by, for example, periodically
cleaning the second electrode plate 532. Further, as will be
described later in modifications of a second embodiment shown in
FIGS. 9A and 9B, the scale adhering to the cathode can be removed
from the cathode by, for example, periodically inverting the
polarity of the electrode plate 53.
[0046] In the cathode during the electrolysis, a reaction occurs in
which hydrogen ions and electrons react with each other to generate
hydrogen (2H.sup.++2e.sup.-.fwdarw.H.sub.2) and pH around the
cathode rises. On the other hand, in the anode during the
electrolysis, a reaction occurs in which water and oxygen are
generated from hydroxide ions
(4OH.sup.-.fwdarw.2H.sub.2O+O.sub.2+4e.sup.-) and pH around the
anode falls.
[0047] FIG. 3A is a schematic diagram showing the electrolysis
device shown in FIG. 2. FIGS. 3B to 3D, FIGS. 4A to 4D, and FIGS.
5A to 5D are schematic diagrams showing the electrolysis devices 41
according to modifications of the first embodiment. These figures
show cross sections of the electrolysis devices 41 viewed from a
side. In the electrolysis devices 41, illustration of the power
supply 51 is omitted. The electrolysis device 41 shown in FIG. 3A
has structure same as the structure of the electrolysis device 41
shown in FIG. 2 explained above. Therefore, explanation of the
electrolysis device 41 is omitted. Concerning the other
modifications, main components are generally explained below.
[0048] The electrolysis device 41 shown in FIG. 3B is the same as
the electrolysis device 41 shown in FIG. 3A in basic structure and
different from the electrolysis device 41 shown in FIG. 3A in a
direction of the device during use. In the electrolysis device 41,
both of the array direction D of the electrode plates 53 and the
longitudinal direction of the container 47 face the up down
direction (the height direction H). In the electrolysis device 41
shown in FIG. 3C, the array direction D of the electrode plates 53
faces the horizontal direction and the longitudinal direction of
the container 47 faces the up down direction. In the electrolysis
device 41 shown in FIG. 3D, the array direction D of the electrode
plates 53 faces the up down direction and the longitudinal
direction of the container 47 faces the horizontal direction.
[0049] The electrolysis devices 41 shown in FIGS. 4A to 4D are
respectively similar to the electrolysis devices 41 shown in FIGS.
3A to 3D and are different from the electrolysis devices 41 shown
in FIGS. 3A to 3D in that the plurality of electrode plates 53
incline as explained below.
[0050] In each of the electrolysis devices 41 shown in FIGS. 4A to
4D, each of the electrode plates 53 is arranged to incline such
that the one end portion 53a is located on one side in the array
direction D (the first wall 471 side in the array direction D) than
the other end portion 53b. For example, in the modification shown
in FIG. 3A, each of the electrode plates 53 is arranged in a
direction substantially parallel to the height direction H of the
container 47. However, in the modification shown in FIG. 4A, each
of the electrode plates 53 is arranged to incline with respect to
the height direction H.
[0051] Since each of the electrode plates 53 is arranged to incline
as explained above, the water channel F formed by the plurality of
electrode plates 53 also inclines in a direction substantially the
same as the inclining direction of the electrode plate 53.
[0052] A flow of water in these modifications is generally as
explained below with reference to, as an example, the electrolysis
device 41 shown in FIG. 4A. That is, an inflow direction of the
water flowing from the one end portion 53a side of the electrode
plate 53 into the water channel F inclines to form an acute angle
(an angle .theta. in FIG. 4A) with a direction in which the water
flowing into the container 47 from the first flow port 43 flows to
the second wall 472 side along the third wall 473.
[0053] Therefore, in the modifications shown in FIGS. 4A to 4D, the
water flowing to the second wall 472 side along the third wall 473
easily flows into the water channel F of each of the electrode
pairs 49 compared with the modifications shown in FIGS. 3A to 3D.
Moreover, the water flowing along the electrode plate 53 through
the water channel F of each of the electrode pairs 49 smoothly
merges with the water flowing through another water channel F on
the fourth wall 474 side.
[0054] In the modifications shown in FIGS. 4A to 4D, since each of
the electrode plates 53 is arranged to incline, compared with the
modifications shown in FIGS. 3A to 3D, the area of each of the
electrode plates 53 can be increased even if the size of the
container 47 is the same.
[0055] The electrolysis devices 41 shown in FIGS. 5A to 5D are
respectively similar in structure to the modifications shown in
FIGS. 4A to 4D in that a plurality of electrode plates incline but
are different in structure from the modifications shown in FIGS. 4A
to 4D in points explained below.
[0056] In the electrolysis devices 41 shown in FIGS. 5A to 5D, a
region on the one end portion 53a side and a region on the other
end portion 53b side of each of the electrode plates 53 incline in
a direction same as the inclining direction of each of the
electrode plates 53 in the modifications shown in FIGS. 4A to 4D. A
region between the region on the one end portion 53a side and the
region on the other end portion 53b side is substantially
perpendicular to the array direction D. In other words, in the
electrolysis devices 41 shown in FIGS. 5A to 5D, each of the
electrode plates 53 includes a non-inclining region substantially
parallel to the height direction H of the container 47, a region on
the one end portion 53a side than the non-inclining region, and a
region on the other end 53b side than the non-inclining region.
[0057] Therefore, in the modifications shown in FIGS. 5A to 5D,
compared with the modifications shown in FIGS. 3A to 3D, the
easiness of inflow into the water channel F of each of the
electrode pair 49 and the smoothness during merging are improved
and the area of each of the electrode plates 53 can be
increased.
Second Embodiment
[0058] FIG. 6 is a sectional view showing the electrolysis device
41 according to a second embodiment of the present invention. FIG.
6 is a diagram of the electrolysis device 41 viewed in the
horizontal direction. As shown in FIG. 6, in the second embodiment,
the configuration of each of the electrode plates 53 is different
from the configuration in the first embodiment. Components same as
the components in the first embodiment are denoted by reference
numerals and signs same as the reference numerals and signs in the
first embodiment and detailed explanation of the components is
omitted.
[0059] In the electrolysis device 41, the plurality of first
electrode plates 531 are respectively extended from the proximal
end portions located in the third wall 473 toward the fourth wall
474. The proximal end of each of the first electrode plates 531 is
coupled to the coupling plate 54 (or the coupling wire 54) extended
in the direction substantially parallel to the third wall 473. An
end portion of the coupling plate 54 is connected to the positive
pole of the power supply 51. The coupling plate 54 is embedded in
the third wall 473. A gap G3 through which water can pass is
provided between the distal end portion (the end portion on the
fourth wall 474 side) of each of the first electrode plates 531 and
the inner surface of the fourth wall 474.
[0060] The plurality of second electrode plates 532 are
respectively extended from the proximal end portions located in the
fourth wall 474 toward the third wall 473. The proximal end portion
of each of the second electrode plates 532 is coupled to the
coupling plate 56 (or the coupling wire 56) extended in the
direction substantially parallel to the fourth wall 474. An end
portion of the coupling plate 56 is connected to the negative pole
of the power supply 51. The coupling plate 56 is embedded in the
fourth wall 474. A gap G4 through which water can pass is provided
between the distal end portion (the end portion on the third wall
473 side) of each of the second electrode plates 532 and the inner
surface of the third wall 473.
[0061] A sectional shape shown in FIG. 6 of the plurality of first
electrode plates 531 and the coupling plate 54 to which the
plurality of first electrode plates 531 are coupled is a comb
shape. Similarly, a sectional shape shown in FIG. 6 of the
plurality of second electrode plates 532 and the coupling plate 56
to which the plurality of second electrode plates 532 are coupled
is a comb shape. The first electrode plates 531 and the second
electrode plates 532 are alternately arranged along the array
direction D. In the electrolysis device 41 according to the second
embodiment having the structure explained above, as shown in FIG.
6, the water channel F has a path that meanders up and down.
[0062] FIG. 7A is a schematic diagram showing the electrolysis
device 41 shown in FIG. 6. FIGS. 7B to 7D are schematic diagrams
showing the electrolysis devices 41 according to modifications of
the second embodiment. These figures show cross sections of the
electrolysis devices 41 viewed from a side.
[0063] The electrolysis device 41 shown in FIG. 7A has structure
same as the structure of the electrolysis device 41 shown in FIG.
6. In the electrolysis device 41, water flowing from the first flow
port 43 into the container 47 flows in the container 47 sideward
while meandering up and down.
[0064] In the electrolysis device 41 shown in FIG. 7B, both the
array direction D of the electrode plates 53 and the longitudinal
direction of the container 47 face the up down direction. In the
electrolysis device 41, the first flow port 43 is provided in the
third wall 473 and located at a corner portion where the first wall
471 and the third wall 473 cross or in the vicinity of the corner
portion. The second flow port 45 is provided in the fourth wall 474
and located at a corner portion where the second wall 472 and the
fourth wall 474 cross or in the vicinity of the corner portion. In
the electrolysis device 41, water flowing from the first flow port
43 into the container 47 flows in the container 47 upward while
meandering to the left and right. The second flow port 45 may be an
inlet and the first flow port 45 may be an outlet.
[0065] In the electrolysis device 41 shown in FIG. 7C, the array
direction D of the electrode plates 53 faces the horizontal
direction and the longitudinal direction of the container 47 faces
the up down direction. A flow of water is the same as the flow of
water in the electrolysis device 41 shown in FIG. 7A.
[0066] In the electrolysis device 41 shown in FIG. 7D, the array
direction D of the electrode plates 53 faces the up down direction
and the longitudinal direction of the container 47 faces the
horizontal direction. In the electrolysis device 41, the first flow
port 43 is provided in the third wall 473 and located at a corner
portion where the first wall 471 and the third wall 473 cross or in
the vicinity of the corner portion. The second flow port 45 is
provided in the fourth wall 474 and located at a corner portion
where the second wall 472 and the fourth wall 474 cross or in the
vicinity of the corner portion. A flow of water is the same as the
flow of water in the electrolysis device 41 shown in FIG. 7B.
[0067] FIGS. 8A and 8B are schematic diagrams showing electrolysis
devices according to still other modifications of the second
embodiment. FIG. 8A shows a cross section of the electrolysis
device 41 viewed from above. FIG. 8B shows a cross section of the
electrolysis device 41 viewed from a side. In the electrolysis
device 41, both of the array direction D of the electrode plates 53
and the longitudinal direction of the container 47 face the
horizontal direction. In the electrolysis device 41, water flowing
from the first flow port 43 into the container 47 flows in the
container 47 sideward while meandering to the left and right.
[0068] FIGS. 8C and 8D are schematic diagrams showing electrolysis
devices according to still other modifications of the second
embodiment. FIG. 8C shows a cross section of the electrolysis
device 41 viewed from the downstream side. FIG. 8D shows a cross
section of the electrolysis device 41 viewed from a side. In the
electrolysis device 41, both of the array direction D of the
electrode plates 53 and the longitudinal direction of the container
47 face the up down direction. In the electrolysis device 41, water
flowing from the first flow port 43 into the container 47 flows in
the container 47 upward while meandering to the left and right.
[0069] FIGS. 8E and 8F are schematic diagrams showing electrolysis
devices according to still other modifications of the second
embodiment. FIG. 8E shows a cross section of the electrolysis
device 41 viewed from above. FIG. 8F shows a cross section of the
electrolysis device 41 viewed from a side. In the electrolysis
device 41, the array direction D of the electrode plates 53 faces
the horizontal direction and the longitudinal direction of the
container 47 faces the up down direction. In the electrolysis
device 41, water flowing from the first flow port 43 into the
container 47 flows in the container 47 sideward while meandering to
the left and right.
[0070] FIGS. 8G and 8H are schematic diagrams showing electrolysis
devices according to still other modifications of the second
embodiment. FIG. 8G shows a cross section of the electrolysis
device 41 viewed from the downstream side. FIG. 8H shows a cross
section of the electrolysis device 41 viewed from a side. In the
electrolysis device 41, the array direction D of the electrode
plates 53 faces the up down direction and the longitudinal
direction of the container 47 faces the horizontal direction. In
the electrolysis device 41, water flowing from the first flow port
43 into the container 47 flows in the container 47 upward while
meandering to the left and right.
[0071] FIGS. 9A and 9B are sectional views showing an electrolysis
device according to still another modification of the second
embodiment. In the electrolysis device 41, components same as the
components of the electrolysis device 41 shown in FIG. 6 are
denoted by the same reference numerals and signs and explanation of
the components is omitted. The electrolysis device 41 according to
this modification includes an inverting mechanism for inverting the
polarity of the electrode plate 53.
[0072] In a state shown in FIG. 9A, the plurality of first
electrode plates 531 is coupled to the positive pole of the power
supply 51 via the coupling plate 54. The plurality of second
electrode plate 532 is coupled to the negative pole of the power
supply 51 via the coupling plate 56. In a state shown in FIG. 9B,
the polarity of the electrode plate 53 is inverted by the inverting
mechanism. That is, the plurality of the first electrode plates 531
is coupled to the negative pole of the power supply 51 via the
coupling plate 54. The plurality of second electrode plate 532 is
coupled to the positive pole of the power supply 51 via the
coupling plate 56. For example, it is possible to invert the
polarity of the electrode plate 53 by switching a contact of a
contact switching section 71 and a contact of a contact switching
section 72 like an inverting mechanism shown in FIG. 9C.
[0073] In this modification, the polarity of the electrode plate 53
is inverted on the basis of a predetermined period or a
predetermined condition such as water quality or temperature
explained below. In the electrolysis device 41, scale adheres to
the cathode because of electrolysis. However, when the polarity of
the electrode plate 53 is inverted to change the electrode plate 53
from the cathode to the anode, pH of liquid locally decreases in
the vicinity of the electrode plate 53. Consequently, a part of the
scale on the surface of the electrode plate 53 melts and drops from
the electrode plate 53. Such inverting operation is repeated at the
predetermined period or under the predetermined condition, whereby
it is possible to suppress the adhesion of scale to the electrode
plate 53.
[0074] FIG. 10 is a sectional view showing a modification of the
heat-pump-type water heater 11. The water heater 11 according to
this modification further includes a bypass pipe 27a for bypassing
the electrolysis device 41. The bypass pipe 27a couples the inflow
water pipe 27 located on the upstream side than the electrolysis
device 41 and the inflow water pipe 27 located on the downstream
side than the electrolysis device 41. For example, as shown in FIG.
10, a valve 81 is attached to the inflow water pipe 27 located on
the upstream side than the electrolysis device 41 and a valve 82 is
attached to the bypass pipe 27a as well. The valve 81 is provided
in the inflow water pipe 27 on the downstream side than a branching
place of the bypass pipe 27a.
[0075] In the electrolysis device 41, when electrolysis is
performed, the valve 81 is opened and the valve 82 is closed. On
the other hand, in the electrolysis device 41, when electrolysis is
not performed, the valve 81 is closed and the valve 82 is opened.
Consequently, when electrolysis is not performed, water can be fed
through the bypass pipe 27a in which the resistance of a flow of
the water is small. Therefore, it is possible to reduce the power
of the pump 31. Since the water is fed to the electrolysis device
41 only when electrolysis is performed, it is possible to suppress
wear (abrasion) of the electrode plate 53.
[0076] FIGS. 11A and 11B are schematic diagrams showing other
modifications of the heat-pump-type water heater 11. These water
heaters 11 include a mechanism for reversing the inlet and the
outlet in the electrolysis device 41.
[0077] First, in the heat-pump-type water heater 11 shown in FIG.
11A, the inflow water pipe 27 located on the upstream side than the
electrolysis device 41 is connected to, for example, a three-way
valve 83. A branch pipe 271 and a branch pipe 272 branch from the
three-way valve 83. The branch pipe 271 is connected to the first
wall 471 of the container 47. The branch pipe 272 is connected to
the second wall 472. The inflow water pipe 27 located on the
downstream side than the electrolysis device 41 is connected to,
for example, a three-way valve 84. A branch pipe 273 and a branch
pipe 274 branch from the three-way valve 84. The branch pipe 273 is
connected to the second wall 472. The branch pipe 274 is connected
to the first wall 471.
[0078] In the heat-pump-type water heater 11, when water is fed in
a direction of a solid line arrow A in the container 47, the
three-way valve 83 and the three-way valve 84 are switched to pass
the water through the branch pipe 271 and the branch pipe 273. On
the other hand, when water is fed in a direction of an arrow B of
an alternate long and two short dashes line in the container 47,
the three-way valve 83 and the three-way valve 84 are switched to
pass the water through the branch pipe 272 and the branch pipe 274.
Consequently, in the container 47, it is possible to reduce a
concentration difference of scale components (a difference in the
electrical conductivity of water) that occurs between a region on
the inlet side and a region on the outlet side. Such switching
operation is performed on the basis of a predetermined period or a
predetermined condition such as water quality or temperature.
[0079] FIG. 12 is a schematic configuration diagram showing still
another modification of the heat-pump-type water heater 11. The
water heater 11 according to this modification further includes a
re-inflow pipe 27b for returning water having passed through the
electrolysis device 41 to the upstream side of the electrolysis
device 41 and causing the water to flow into the electrolysis
device 41 again. The re-inflow pipe 27b couples the inflow water
pipe 27 located on the upstream side than the electrolysis device
41 and the inflow pipe 27 located on the downstream side than the
electrolysis device 41.
[0080] In the re-inflow pipe 27b, an open-closable valve 92 and a
pump 91 are provided. The pump 91 plays a role for feeding a part
of water, which flows through the inflow pipe 27 on the downstream
side, in a direction of an arrow in FIG. 12 through the re-inflow
pipe 27b and causing the water to merge with the inflow pipe 27 on
the upstream side.
[0081] In the inflow water pipe 27 located on the upstream side
than the electrolysis device 41, a check valve 93 is provided in a
position on the upstream side than a connecting place to the
re-inflow pipe 27b. In the inflow water pipe 27 located on the
downstream side than the electrolysis device 41, a check valve 94
is provided in a position on the downstream side than the
connecting place to the re-inflow pipe 27b.
[0082] In normal operation of the electrolysis device 41, the valve
92 is closed and the pump 91 is stopped. On the other hand, when it
is desired to improve the efficiency of electrolysis in the
electrolysis device 41 to be higher than the efficiency during the
normal operation, the valve 92 is opened and the pump 91 is driven.
When the pump 91 is driven, a part of water flowing out from the
electrolysis device 41 flows into the inflow water pipe 27 on the
upstream side of the electrolysis device 41 again through the
re-inflow pipe 27b, merges with water flowing through the inflow
water pipe 27, and flows into the electrolysis device 41.
[0083] FIGS. 13A and 13B are schematic diagrams showing other
modifications of the heat-pump-type water heater 11. The water
heaters 11 according to the modifications further include a sensor
95. In the water heater 11 shown in FIG. 13A, the sensor 95 is
attached to the inflow water pipe 27 located on the upstream side
than the electrolysis device 41. In the water heater 11 shown in
FIG. 13B, the sensor 95 is attached to the inflow water pipe 27
located on the downstream side than the electrolysis device 41.
[0084] Examples of the sensor 95 include a water quality
measurement sensor and a temperature sensor. When the sensor 95 is
the water quality measurement sensor, the hardness of water is
detected by measuring, for example, the electrical conductivity of
the water with the sensor 95.
[0085] The control unit 33 controls the power supply 51 to adjust a
voltage applied to each of the electrode pairs 49 according to the
quality of water flowing through the inflow water pipe 27.
Specifically, in the case of the quality of water that has high
hardness and tends to cause scale, the control unit 33 applies a
high voltage to each of the electrode pairs 49. Consequently, it is
possible to improve a removal effect for scale components in the
electrolysis device 41. On the other hand, in the case of the
quality of water that has low hardness and does not tend to scale,
the control unit 33 applies a voltage lower than the above to each
of the electrode pairs 49. Consequently, it is possible to reduce
power consumption.
[0086] When the sensor 95 is the temperature sensor, the control
unit 33 controls the power supply 51 to apply a high voltage to
each of the electrode pairs 49 when water temperature detected by
the sensor 95 is higher than a predetermined value set in advance.
On the other hand, the control unit 33 controls the power supply 51
to apply a voltage lower than the above to each of the electrode
pairs 49 when water temperature detected by the sensor 95 is equal
to or lower than the predetermined value. Consequently, it is
possible to reduce power consumption.
[0087] The power supply 51 may be controlled on the basis of, for
example, set temperature of the water heater 11 rather than being
controlled on the basis of water temperature detected by the sensor
95 as explained above. For example, in the water heater 11, the
temperature of water heated by the water heat exchanger 21 is set
to, for example, high temperature of 85.degree. C. to 90.degree. C.
in winter. The temperature of water heated by the water heat
exchanger 21 is set to, for example, relatively low temperature of
about 60.degree. C. in summer. The control unit 33 controls the
power supply 51 to apply a voltage to each of the electrode pairs
49 in the electrolysis device 41 in winter when the set temperature
is high. In summer, the control unit 33 controls the power supply
51 to not apply a voltage to each of the electrode pairs 49 or such
that an applied voltage is lower than the applied voltage in
winter.
[0088] As explained above, in the embodiment, since the plurality
of electrode pairs 49 are disposed in the container 47, it is
possible to improve the removal efficiency for scale components
compared with the conventional electrolysis device 41 in which one
electrode pair 49 is set in the electrolytic cell. The plurality of
electrode plates 53 are arrayed spaced apart from one another in
the thickness direction. Water flowing from the inlet into the
container 47 reaches the outlet after passing between the pair of
electrode plates 53 in each of the electrode pairs 49. By adopting
such a configuration, it is possible to increase a contact area of
the electrodes and water while suppressing a volume occupied by the
plurality of electrode pairs 49.
[0089] In the embodiment, one of the inlet and the outlet for water
is provided on one side in the array direction D of the plurality
of electrode plates 53. The other of the inlet and the outlet for
water is provided on the other side in the array direction of the
plurality of electrode plates 53. Since the inlet and the outlet
are provided on the one side and the other side in the array
direction D, it is easy to supply water to all the plurality of
electrode pairs 49. Therefore, it is possible to further improve
the removal efficiency for scale components.
[0090] In the first embodiment, water flowing from the inlet
provided in the first wall 471 into the container 47 flows to the
second wall 472 side along the third wall 473 through a gap between
one end portion of each of the electrode plates 53 and the third
wall 473. A part of the water flowing along the third wall 473
flows into between the electrode plates of each of the electrode
pairs 49 arranged in the array direction D. The water flowing along
the electrode plates 53 between the electrode plates of each of the
electrode pairs 49 merges on the fourth wall 474 side and flows out
to the outside of the container 47 from the second flow port
45.
[0091] In this modification of the first embodiment, each of the
electrode plates 53 is arranged to incline such that the one end
portion 53a is located on one side in the array direction D than
the other end portion 53b. Since each of the electrode plates 53 is
arranged to incline as explained above, the water channel F formed
by the plurality of electrode plates 53 also inclines in a
direction substantially the same as the inclining direction of the
electrode plate 53. An inflow direction in which water flows from
the one end portion 53a side into the water channel F inclines to
form an acute angle with a flowing direction in which the water
flowing from the inlet into the container 47 flows to the second
wall 472 side along the third wall 473. Therefore, the water
flowing from the inlet provided in the first wall 471 into the
container 47 and flowing to the second wall 472 side along the
third wall 473 through the gap between the one end portion 53a of
each of the electrode plates 53 and the third wall 473 easily flows
into between the electrode plates of each of the electrode pairs 49
arranged in the array direction D.
[0092] In the second embodiment, the first electrode plates 531 and
the second electrode plates 532 are alternately arranged along the
array direction D and the water channel F has the serpentine flow
path. Water flowing from the inlet into the container 47 flows
along the serpentine flow path to thereby pass between the pair of
electrode plates 53 in each of the electrode pairs 49 in order.
Consequently, it is possible to uniformly supply the water flowing
from the inlet into the container 47 to all the plural electrode
pairs 49. Therefore, it is possible to further improve the removal
efficiency for scale components.
[0093] In the embodiments, the electrolysis device 41 is provided
in the feed channel 27. In the feed channel 27, the flow velocity
of water is low and fluctuation in the flow velocity is small.
Therefore, the flow velocity of water passing through the
electrolysis device 41 is generally fixed at a low flow velocity.
Consequently, in the electrolysis device 41, it is possible to
stably obtain an effective removal effect for scale components.
Since electrolysis is performed during the operation of the heat
pump, it is possible to use night-time electric power and reduce
electricity charges.
[0094] In the embodiment, a voltage is applied to each of the
electrode pairs 49 when the temperature of water is equal to or
higher than a value set in advance at which scale tends to occur.
Otherwise, a voltage is not applied and power consumption can be
reduced.
[0095] In the embodiment, a voltage applied to each of the
electrode pairs 49 is adjusted according to water quality such as
the hardness of water. Therefore, it is possible to apply a voltage
necessary for the water quality. Consequently, it is possible to
suppress application of an excess voltage and reduce power
consumption while improving the removal efficiency for scale
components.
[0096] In the embodiment, water having passed through the
electrolysis device 41 can be caused to flow into the electrolysis
device 41 again through a re-inflow channel. Therefore, it is
possible to further improve the removal efficiency for scale
components while suppressing the size of the electrolysis device 41
from increasing.
[0097] In the embodiment, since the inlet and the outlet are
reversed by the reversing mechanism, in the container 47, it is
possible to reduce a concentration difference of scale components
(a difference in the electrical conductivity of water) that occurs
between the region on the inlet side and the region on the outlet
side. Consequently, in the container 47, a difference in
electrolysis efficiency between the region on the inlet side and
the region on the outlet side decreases. Therefore, it is possible
to improve electrolysis efficiency in the entire electrolysis
device 41. It is also possible to maintain or improve the removal
efficiency for scale components while suppressing total power
consumption. Further, it is possible to reduce, among the plurality
of electrode plates, fluctuation in an amount of scale adhering to
the electrode plate 53. Consequently, it is possible to suppress
scale from being precipitated only on a specific electrode plate
53. Therefore, for example, it is possible to extend a period of
the operation for inverting the polarity explained above. Further,
it is also possible to perform operation for only cleaning of the
cathode while omitting the inverting operation for the
polarity.
[0098] In the specific embodiments explained above, inventions
including configurations explained below are mainly included.
[0099] An electrolysis device according to the present invention is
used in a water heater including a water heat exchanger for heating
water. The electrolysis device includes a container, a plurality of
electrode pairs, and a power supply. The container includes a first
flow port functioning as one of an inlet and an outlet for water,
and a second flow port functioning as the other of the inlet and
the outlet for water. The plurality of electrode pairs are disposed
in the container. The power supply applies a voltage to each of the
electrode pairs. Each of the electrode pairs includes a pair of
electrode plates. A plurality of the electrode plates are arrayed
spaced apart from one another in the thickness direction of the
electrode plate. In the electrolysis device, a water channel is
formed by the plurality of electrode plates such that water flowing
from the inlet into the container reaches the outlet after passing
between the pair of electrode plates in each of the electrode
pairs.
[0100] In this configuration, since the plurality of electrode
pairs are disposed in the container, it is possible to improve
removal efficiency for scale components compared with the
conventional electrolysis device in which one electrode pair is set
in an electrolytic cell. Each of the electrode pairs includes a
pair of electrode plates. Therefore, the plurality of electrode
pairs are configured by a plurality of electrode plates. The
plurality of electrode plates are arrayed spaced apart from one
another in the thickness direction. Water flowing from the inlet
into the container reaches the outlet after passing between the
pair of electrode plates in each of the electrode pairs. By
adopting such a configuration, it is possible to increase a contact
area of the electrodes and water while suppressing a volume
occupied by the plurality of electrode pairs.
[0101] In the electrolysis device, it is preferable that the
container includes a first wall located on one side in an array
direction of the plurality of electrode plates, a second wall
located on the other side in the array direction and opposed to the
first wall across the plurality of electrode plates, and a sidewall
that extends along the array direction to surround the plurality of
electrode plates and connects the first wall and the second wall.
In this case, it is preferable that the first flow port is provided
in the first wall or in the vicinity of the first wall, and the
second flow port is provided in the second wall or in the vicinity
of the second wall.
[0102] In this configuration, one of the inlet and the outlet for
water is provided on the one side in the array direction of the
plurality of electrode plates and the other of the inlet and the
outlet for water is provided on the other side in the array
direction of the plurality of electrode plates. Since the inlet and
the outlet are provided on the one side and the other side in the
array direction, it is easy to supply water to all the plurality of
electrode pairs. Therefore, it is possible to further improve the
removal efficiency for scale components.
[0103] Preferred arrangement examples of the plurality of electrode
plates include a configuration explained below. In the electrolysis
device, it is preferable that the sidewall includes a third wall
extending along the array direction, and a fourth wall extending
along the array direction and opposed to the third wall across the
plurality of electrode plates, the plurality of electrode plates
include first electrode plates connected to one pole of the power
supply and second electrode plates connected to the other pole of
the power supply, each of the first electrode plates is extended
from a proximal end portion of the first electrode plate located in
the third wall toward the fourth wall, and each of the second
electrode plates is extended from a proximal end portion of the
second electrode plate located in the fourth wall toward the third
wall. In this case, it is preferable that the first electrode
plates and the second electrode plates are arranged orthogonal to
each other along the array direction, whereby the water channel
includes a serpentine flow path.
[0104] In this configuration, the first electrode plates and the
second electrode plates are alternately arranged along the array
direction and the water channel includes the serpentine flow path.
Water flowing from the inlet into the container flows along the
serpentine flow path to thereby pass between the pair of electrode
plates in each of the electrode pairs in order from the electrode
pair on the inlet side. Consequently, it is possible to supply the
water flowing from the inlet into the container to all of the
plurality of electrode pairs. Therefore, it is possible to further
improve the removal efficiency for scale components.
[0105] Another arrangement example of the plurality of electrode
plates includes a configuration explained below. For example, in
the electrolysis apparatus, the sidewall includes a third wall
extending along the array direction, and a fourth wall extending
along the array direction and opposed to the third wall across the
plurality of electrode plates. A gap through which the water can
pass is provided between one end portion of each of the electrode
plates and the third wall. A gap through which the water can pass
is provided between the other end portion of each of the electrode
plates and the fourth wall. The first flow port is provided in the
first wall in a position closer to the third wall than the fourth
wall. The second flow port is provided in the second wall in a
position closer to the fourth wall than the third wall.
[0106] In this configuration, an example is explained in which the
first flow port functions as the inlet and the second flow port
functions as the outlet. The water flowing from the inlet into the
container flows out from the outlet roughly through a path
explained below. That is, the water flowing from the inlet provided
in the first wall into the container flows to the second wall side
along the third wall through the gap between the one end portion of
each of the electrode plates and the third wall. A part of the
water flowing along the third wall flows into between the electrode
plates of each of the electrode pairs arranged in the array
direction. The water flowing along the electrode plates between
electrode plates of each of the electrode pairs merges on the
fourth wall side, flows to the second wall side along the fourth
wall, and flows out to the outside of the container from the second
flow port.
[0107] In the electrolysis device, it is preferable that each of
the electrode plates are arranged to incline such that the one end
portion is located on the one side in the array direction than the
other end portion.
[0108] In this configuration, since each of the electrode plates
are arranged to incline as explained above, the water channel
formed by the plurality of electrode plates inclines in a direction
substantially the same as the inclining direction of the electrode
pair. For example, when a flow of water is explained with reference
to an example in which the first flow port functions as the inlet,
the water flows as explained below. That is, the inflow direction
in which the water flows from the one end portion side into between
the electrode plates of each of the electrode pairs (the water
channel) inclines to form an acute angle with a flowing direction
in which the water flowing into the container flows to the second
wall side along the third wall. Therefore, the water flowing to the
second wall side along the third wall easily flows into between the
electrode plates of each of the electrode pairs arranged in the
array direction.
[0109] Incidentally, in a heat-pump-type water heater, heated water
(hot water) of which is used by a user, rather than the cooling
water circulating apparatus of the circulation type for circulating
water as cooling water as in Patent Document 1, water containing
scale components is periodically filled from a water supply source
such as tap water or well water to a tank. Therefore, in the case
of the heat-pump-type water heater, compared with the cooling water
circulating apparatus of the circulation type, it is necessary to
efficiently remove scale components. In particular, when
underground water such as well water is used as the water supply
source, scale tends to be precipitated.
[0110] Therefore, a heat-pump-type water heater according to the
present invention includes a heat pump unit which includes a water
heat exchanger for heating water, and in which a refrigerant
circulates through a refrigerant pipe, a hot water storage unit
including a tank in which the water is stored, a feed channel for
feeding the water in the tank to the water heat exchanger, and a
return channel for returning the water heated by the water heat
exchanger to the tank, a water supply pipe for supplying the water
from a water supply source to the tank, a hot water supply pipe for
supplying high-temperature water stored in the tank, and the
electrolysis device for removing scale components contained in the
water.
[0111] In this configuration, the electrolysis device that can
improve the removal efficiency for scale components compared with
the conventional electrolysis device is provided. Therefore, even
in the heat-pump-type water heater, it is possible to effectively
suppress scale from being precipitated in the water heat
exchanger.
[0112] Further, in the heat-pump-type water heater, it is
preferable that the electrolysis device is provided in the feed
channel.
[0113] In this configuration, the electrolysis device is provided
in the feed channel. Since the flow velocity of the water is low in
the feed channel and fluctuation in the flow velocity is small, the
flow velocity of water passing through the electrolysis device is
generally fixed at a low flow velocity. Consequently, in the
electrolysis device, it is possible to stably obtain an effective
removal effect for scale components. Since electrolysis is
performed during the operation of the heat pump, it is possible to
use night-time electric power and reduce electricity charges.
[0114] It is preferably that the heat-pump-type water heater
further includes a control unit configured to control the power
supply for the electrolysis device. In this case, it is preferable
that the control unit controls the power supply such that a voltage
is applied to each of the electrode pairs when the temperature of
water heated by the water heat exchanger is equal to or higher than
a value set in advance.
[0115] In this configuration, a voltage is applied to each of the
electrode pairs when the temperature of water is equal to or higher
than the value set in advance. Otherwise, a voltage is not applied
and power consumption can be reduced.
[0116] It is preferable that the heat-pump-type water heater
further includes a control unit configured to control the power
supply for the electrolysis device. In this case, it is preferable
that the control unit controls the power supply to adjust a voltage
applied to each of the electrode pairs according to water quality
in the hot water storage unit.
[0117] In this configuration, the voltage applied to each of the
electrode pairs is adjusted according to water quality such as the
hardness of water. Therefore, it is possible to apply a voltage
necessary for the water quality. Consequently, it is possible to
suppress application of an excessive voltage and reduce power
consumption while improving the removal efficiency for scale
components.
[0118] In the heat-pump-type water heater, it is preferable that
the feed channel includes a re-inflow channel for returning water
having passed through the electrolysis device to the upstream side
of the electrolysis device and causing the water to flow into the
electrolysis device again.
[0119] In this configuration, it is possible to cause the water
having passed through the electrolysis device to flow into the
electrolysis device again through the re-inflow channel. Therefore,
it is possible to further improve the removal efficiency for scale
components while suppressing the size of the electrolysis device
from increasing.
[0120] It is preferable that the heat-pump-type water heater
further includes a reversing mechanism for reversing the inlet and
the outlet in the electrolysis device.
[0121] In a process in which the water flows from the upstream side
to the downstream side in the container of the electrolysis device,
scale components contained in the water are gradually removed.
Therefore, the concentration of an electrolyte is lower in a region
on the downstream side than in a region on the upstream side.
Therefore, the removal efficiency for scale components tends to be
lower in the region on the downstream side than in the region on
the upstream side. In this configuration, the inlet and the outlet
are reversed by the mechanism, whereby it is possible to reduce a
concentration difference in scale components (a difference in the
electrical conductivity of water) that occurs between the region on
the inlet side and the region on the outlet side in the container.
Consequently, in the container, a difference in electrolysis
efficiency between the region on the inlet side and the region on
the outlet side decreases. Therefore, it is possible to improve
electrolysis efficiency in the entire electrolysis device. It is
also possible to maintain or improve the removal efficiency for
scale components while suppressing total power consumption.
Further, it is possible to reduce, among the plurality of electrode
plates, fluctuation in an amount of scale adhering to the electrode
plate. Consequently, it is possible to suppress scale from being
precipitated only on a specific electrode plate.
[0122] It is preferable that the electrolysis device is used in the
one-through type heat-pump-type water heater. In the one-through
type water heater, since hot water supplied from the hot water
supply pipe is not returned to the tank, water of substantially the
same amount as an amount of water discharged from the tank through
the hot water supply pipe is supplied from the water supply source
to the tank through the water supply pipe. Therefore, it is
necessary to efficiently remove the scale components compared with
the cooling water circulating apparatus of the circulation type or
the water heater of the circulation type. Since the electrolysis
device is excellent in removal efficiency for scale components, the
electrolysis device is suitable for the one-through heat-pump-type
water heater as well.
[0123] The present invention is not limited to the embodiments, and
various modifications, improvements, and the like are possible
without departing from the spirit of the present invention. For
example, in the form illustrated in the embodiment, the first flow
port is provided in the first wall and the second flow port is
provided in the second wall. However, the present invention is not
limited to this. The first flow port 43 may be provided in the
vicinity of the first wall 471, and the second flow port 45 may be
provided in the vicinity of the second wall 472. Specifically, for
example, the first flow port 43 may be provided in the third wall
473 in the vicinity of the first wall 471, and the second flow port
45 may be provided in the fourth wall 474 in the vicinity of the
second wall 472.
[0124] In the embodiment, the characteristics of the modifications
shown in FIGS. 9 to 13 are explained with reference to, as the
example, the second embodiment including the serpentine flow path.
However, for example, the characteristic components in the
modifications shown in FIGS. 9 to 13 may be added to the
electrolysis device 41 according to the first embodiment shown in
FIG. 2.
[0125] Each of the electrode plates may be formed in a mesh shape
in which a plurality of small through-holes are formed or may be
formed in a bar shape. When the electrode plate has the bar shape,
a shorter one of dimensions in two directions orthogonal on a cross
section perpendicular to the longitudinal direction of the
electrode plate is set as thickness and a longer one of the
dimensions is set as width.
[0126] The embodiment is mainly explained with reference to, as the
example, the case in which the first flow port functions as the
inlet and the second flow port functions as the outlet. However,
the first flow port may be the outlet and the second flow port may
be the inlet.
[0127] The embodiment is explained with reference to, as the
example, the case in which the electrolysis device 41 is provided
in the inflow water pipe 27 on the downstream side than the pump 31
in the water heater 11 as shown in FIG. 1. However, the present
invention is not limited to this. The electrolysis device 41 may be
provided in the inflow water pipe 27 on the upstream side than the
pump 31 or may be provided in the water supply pipe 37 for
supplying water from the water supply source to the tank 15.
[0128] The embodiment is explained with reference to, as the
example, the case in which the container 47 has the substantially
rectangular parallelepiped shape. However, the present invention is
not limited to this. The container 47 may be formed in a prism
shape other than a rectangular parallelepiped or may be a columnar
shape.
[0129] In the embodiments, the one-through type water heater is
explained as the example. However, the present invention is not
limited to this.
EXPLANATION OF REFERENCE NUMERALS
[0130] 11 water heater
[0131] 13 heat pump unit
[0132] 15 tank
[0133] 17 hot water storage unit
[0134] 21 water heat exchanger
[0135] 27 inflow water pipe (an example of a feed channel)
[0136] 27a bypass pipe
[0137] 27b re-inflow pipe (an example of a re-inflow channel)
[0138] 29 outflow hot water pipe (an example of a return
channel)
[0139] 31 pump
[0140] 33 control unit
[0141] 35 hot water supply pipe
[0142] 37 water supply pipe
[0143] 41 electrolysis device
[0144] 43 first flow port
[0145] 45 second flow port
[0146] 47 container
[0147] 471 first wall
[0148] 472 second wall
[0149] 473 third wall
[0150] 474 fourth wall
[0151] 48 sidewall
[0152] 49 electrode pairs
[0153] 51 power supplies
[0154] 53 electrode plates
[0155] 531 first electrode plates
[0156] 532 second electrode plates
[0157] D array direction of a plurality of electrode plates
[0158] F water channel
* * * * *