U.S. patent application number 15/818313 was filed with the patent office on 2018-05-31 for heating device with hot water supply function.
This patent application is currently assigned to NORITZ CORPORATION. The applicant listed for this patent is NORITZ CORPORATION. Invention is credited to Akihisa KAGEYAMA, Toshihiro KAWACHI, Yoshihisa KITANO, Yasutaka KURIYAMA, Hiroshi MORIMOTO, Yasushi MORITA, Midori YOKOYAMA, Takehito YOKOYAMA.
Application Number | 20180149373 15/818313 |
Document ID | / |
Family ID | 62190021 |
Filed Date | 2018-05-31 |
United States Patent
Application |
20180149373 |
Kind Code |
A1 |
MORITA; Yasushi ; et
al. |
May 31, 2018 |
HEATING DEVICE WITH HOT WATER SUPPLY FUNCTION
Abstract
A heating device with hot water supply function includes: a
combustion means; a main heat exchanger; a circulation passage
connecting the main heat exchanger to an heating apparatus; a
circulation pump provided in the circulation passage; a bypass
passage that branches off from the circulation passage and bypasses
the room heating apparatus; a secondary heat exchanger provided in
the bypass passage; a cold water supply passage for supplying cold
water to the secondary heat exchanger; a hot water supply passage
for supplying hot water heated by the secondary heat exchanger; a
hot water supply bypass passage that connects the cold water supply
passage to the hot water supply passage bypassing the secondary
heat exchanger; a flow adjustment means for adjusting the flow rate
in the hot water supply bypass passage and thereby controlling the
temperature of hot water to be supplied; and an expanded passage
portion of the hot water supply passage whose diameter is increased
from an intermediate portion of the hot water supply passage to its
downstream end.
Inventors: |
MORITA; Yasushi; (Kobe-shi,
JP) ; KAWACHI; Toshihiro; (Kobe-shi, JP) ;
KURIYAMA; Yasutaka; (Kobe-shi, JP) ; KITANO;
Yoshihisa; (Kobe-shi, JP) ; MORIMOTO; Hiroshi;
(Kobe-shi, JP) ; YOKOYAMA; Midori; (Kobe-shi,
JP) ; KAGEYAMA; Akihisa; (Kobe-shi, JP) ;
YOKOYAMA; Takehito; (Kobe-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NORITZ CORPORATION |
Hyogo |
|
JP |
|
|
Assignee: |
NORITZ CORPORATION
Hyogo
JP
|
Family ID: |
62190021 |
Appl. No.: |
15/818313 |
Filed: |
November 20, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24D 3/02 20130101; F24D
19/1069 20130101; F24D 3/087 20130101 |
International
Class: |
F24D 19/10 20060101
F24D019/10; F24D 3/02 20060101 F24D003/02; F24D 3/08 20060101
F24D003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2016 |
JP |
2016-228814 |
Claims
1. A heating device with hot water supply function, comprising: a
combustion means; a main heat exchanger; a circulation passage
connecting the main heat exchanger to a heating apparatus; a
circulation pump provided in the circulation passage; a bypass
passage that branches off from the circulation passage and bypasses
the heating apparatus; a secondary heat exchanger, provided in the
bypass passage; a cold water supply passage for supplying cold
water to the secondary heat exchanger; a hot water supply passage
for supplying hot water to which heat has been supplied by the
secondary heat exchanger; a hot water supply bypass passage that
connects the cold water supply passage to the hot water supply
passage, bypassing the secondary heat exchanger; a flow adjustment
means for adjusting a flow rate in the hot water supply bypass
passage and thereby controlling the temperature hot water to be
supplied; and an expanded passage portion of the hot water supply
passage, whose diameter is expanded from an intermediate portion of
the hot water supply passage to a downstream end of the hot water
supply passage.
2. The heating device with hot water supply function according to
claim 1, wherein the hot water supply bypass passage is connected
to the expanded passage portion.
3. The heating device with hot water supply function according to
claim 1, wherein a diameter of the hot water supply bypass passage
is smaller than a diameter of the hot water supply passage on an
upstream side than the intermediate portion thereof.
4. The heating device with hot water supply function according to
claim 1, wherein a temperature detection means is provided in the
hot water supply passage on the upstream side than the intermediate
portion thereof.
5. The heating device with hot water supply function according to
claim 1; wherein a distribution means is provided in a branching
portion where the bypass passage branches off from the circulation
passage; and the distribution means is capable of adjusting its
distribution ratio, so that it becomes possible to perform only
room heating operation, or only hot water supply operation, or
simultaneous room heating and hot water supply operation.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a heating device with hot
water supply function that performs room heating by supplying heat
to a room heating medium by combustion of fuel, and that also
performs hot water supply by supplying heat to cold water by heat
exchange with this room heating medium; and in particular relates
to a heating device with hot water supply function that supplies
hot water at a high flow rate by adjusting the temperature of the
hot water by mixing with cold water at a low temperature.
[0002] Previously, heating devices with hot water supply function
have been widely used that are capable of changing over between
room heating operation and hot water supply operation. This type of
heating device with hot water supply function comprises a
combustion means, a main heat exchanger, a circulation passage
connecting between the main heat exchanger and a room heating
apparatus that is installed inside a building, a circulation pump
provided in the circulation passage, a bypass passage that branches
off from the circulation passage so as to bypass the room heating
apparatus, and so on. A changeover means is provided at the portion
where the bypass passage branches off from the circulation passage,
and the changeover means is capable of being changed over so that
the room heating medium flows either in the circulation passage or
in the bypass passage. A secondary heat exchanger is provided in
the bypass passage, and both a cold water supply passage that
supplies cold water to the secondary heat exchanger, and also a hot
water supply passage for supplying hot water from the heat
exchanger to a hot water supply faucet or the like, are connected
thereto.
[0003] By utilizing the heat of combustion from the combustion
means, the main heat exchanger supplies heat to the room heating
medium that flows due to the operation of the circulation pump. And
during room heating operation, in order for the room heating medium
to which heat has thus been supplied to be utilized by the room
heating apparatus, the changeover means is changed over so that the
room heating medium flows through the circulation passage. Thus,
the room heating medium to which heat has been supplied flows
through the circulation passage and its heat is dissipated by the
room heating apparatus, and then the thermal medium returns to the
main heat exchanger.
[0004] During hot water supply operation, in order for the room
heating medium to which heat has been supplied to be utilized by
the secondary heat exchanger, the changeover means is changed over
so that the room heating medium flows through the bypass passage.
Cold water supplied from the cold water supply passage is heated up
in the secondary heat exchanger by exchange of heat with the room
heating medium. And the room heating medium that has thus exchanged
heat with cold water in the secondary heat exchanger then returns
to the main heat exchanger. The heated water which is heated by the
secondary heat exchanger is then supplied via the hot water supply
passage to the hot water supply faucet. At this time, adjustment of
the hot water supply temperature is performed via the room heating
medium by adjusting the strength of combustion in the combustion
means, and/or by adjusting the flow rate of the circulation
pump.
[0005] Since, in this heating device with hot water supply
function, adjustment of the hot water supply temperature is
performed indirectly via the room heating medium, accordingly it is
difficult to perform this adjustment so that the temperature of the
supplied hot water does not change in response to fluctuations of
the hot water supply flow rate. Due to this, the present applicant
has already proposed a heating device with hot water supply
function in which the hot water supply temperature is adjusted by
mixing together heated water to which heat has been supplied by the
room heating medium in the secondary heat exchanger, and cold water
whose flow rate in a hot water supply bypass passage that bypasses
this secondary heat exchanger is adjusted (refer to Japanese Patent
Application 2016 146594 etc.).
[0006] Furthermore, when for example a supply of hot water is
requested from the heating device with hot water supply function at
a high flow rate of 40 liters per minute or higher, then the hot
water flows at high speed in the hot water supply passage. Thus,
there is a danger that a conduit that is incorporated in the hot
water supply passage may suffer wear due to this high speed water
flow and that erosion thereof may take place, so that one or more
holes may open up in the conduit. For combatting such erosion, a
structure is per se known and described in the cited document below
in which erosion is suppressed by making one of the conduits to
have a greater diameter at the junction between the two conduits,
thus lowering the flow speed.
[0007] Prior patent document: Japanese Patent Publication
3,911,348
[0008] When adjustment of the hot water supply temperature is
performed by mixing with cold water, if the extent of mixing with
cold water is insufficient, then the hot water supply temperature
becomes non uniform, and this is not desirable. Moreover, there is
a danger that, due to adjustment of the hot water supply
temperature on the basis of this non uniform temperature, it may
not be possible to adjust the hot water supply temperature in an
appropriate manner. Due to this, it is necessary to make the
passage after mixing long, in order to mix the hot water to which
heat has been applied and the cold water sufficiently well
together. However, if a long passage is provided, then the
resistance to water flow becomes large, and this is disadvantageous
from the point of view of providing supply of hot water at a high
flow rate.
[0009] The object of the present invention is to provide a heating
device with hot water supply function that, along with being
capable of adjusting the temperature of the hot water and providing
hot water at a uniform temperature, also is capable of providing
hot water supply at a high flow rate.
SUMMARY OF THE INVENTION
[0010] The present invention presents a heating device with hot
water supply function, comprising: a combustion means; a main heat
exchanger; a circulation passage connecting the main heat exchanger
to a heating apparatus; a circulation pump provided in the
circulation passage; a bypass passage that branches off from the
circulation passage and bypasses the heating apparatus; a secondary
heat exchanger, provided in the bypass passage; a cold water supply
passage for supplying cold water to the secondary heat exchanger; a
hot water supply passage for supplying hot water to which heat has
been supplied by the secondary heat exchanger; a hot water supply
bypass passage that connects the cold water supply passage to the
hot water supply passage, bypassing the secondary heat exchanger; a
flow adjustment means for adjusting a flow rate in the hot water
supply bypass passage and thereby controlling the temperature of
hot water to be supplied; and an expanded passage portion of the
hot water supply passage, whose diameter is expanded from an
intermediate portion of the hot water supply passage to a
downstream end of the hot water supply passage.
[0011] Since, according to the present invention, the hot water
supply temperature is controlled by mixing the cold water flowing
in the hot water supply bypass passage whose flow rate is adjusted
with the hot water heated by the secondary heat exchanger,
accordingly it is possible to perform adjustment in response to
change of the hot water supply flow rate, so that the hot water
supply temperature does not vary. Moreover, since the volumetric
capacity of the hot water supply passage is increased due to the
expanded passage portion and thus the flow speed is reduced,
accordingly the passage becomes substantively longer. Therefore it
is possible to supply hot water at a uniform hot water supply
temperature, since it is possible to perform sufficient mixing
together of the hot water and the cold water in the expanded
passage portion. Furthermore, since the flow resistance is lowered
due to the provision of the expanded passage portion, accordingly
this is beneficial from the point of view of supplying hot water at
a high flow rate, and moreover the flow speed is lowered, which is
beneficial for suppression of erosion.
[0012] Yet further, it is possible to provide a heating device with
hot water supply function that, along with being able to provide a
supply of hot water at a uniform temperature by adjusting the hot
water supply temperature, can also provide the hot water at a high
flow rate.
[0013] In a preferred first aspect of the present invention, the
hot water supply bypass passage is connected to the expanded
passage portion.
[0014] According to this first aspect, since the flow speed within
the expanded passage portion is low, accordingly the mixing
together of the hot water and the cold water is promoted.
[0015] Furthermore, in a preferred second aspect of the present
invention, a diameter of the hot water supply bypass passage is
smaller than a diameter of the hot water supply passage on an
upstream side than the intermediate portion thereof.
[0016] According to this second aspect, it is possible to prevent
the hot water that is flowing in the hot water supply passage from
flowing in reverse through the hot water supply bypass passage.
[0017] Moreover, in a preferred third aspect of the present
invention, a temperature detection means is provided in the hot
water supply passage on the upstream side than the intermediate
portion thereof.
[0018] According to this third aspect, it is possible to ensure
that the temperature that is detected by the temperature detection
means does not experience any influence from the hot water that is
mixed with the cold water. Accordingly, it is possible to detect
the temperature of the heated water that is outputted from the
secondary heat exchanger in an accurate manner, and it is thereby
possible to perform adjustment of the hot water supply
temperature.
[0019] And, in a preferred fourth aspect of the present invention,
a distribution means is provided in a branching portion where the
bypass passage branches off from the circulation passage; and the
distribution means is capable of adjusting its distribution ratio,
so that it becomes possible to perform only room heating operation,
or only hot water supply operation, or simultaneous room heating
and hot water supply operation.
[0020] According to this fourth aspect, it is possible to utilize
both room heating and hot water supply at the same time, so that
the convenience is enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic figure showing a heating device with
hot water supply function according to an embodiment of the present
invention; and
[0022] FIG. 2 is a perspective view of a conduit, on the downstream
side of a secondary heat exchanger, that constitutes a hot water
supply passage.
DETAILED DESCRIPTION
[0023] Now, a concrete embodiment of the present invention will be
explained.
[0024] First, the overall structure of a heating device with hot
water supply function 1 according to the present invention will be
explained with reference to FIG. 1.
[0025] The heating device with hot water supply function 1 performs
room heating operation by circulating a room heating medium that
has been heated by employing heat generated by a combustion unit 2
to a room heating apparatus (not shown in the figure) that is
installed inside a building and externally to this heating device
with hot water supply function 1, and that is adapted to perform
warm water supply operation in which hot water (warm water) is
supplied by adjusting cold water that has been heated to a set hot
water supply temperature by utilizing the heat of the room heating
medium.
[0026] The heating device with hot water supply function 1
comprises a combustion unit 2 which is a combustion means, a main
heat exchanger 10, a circulation passage 4 that connects the room
heating apparatus (H.A.) that is provided inside the building with
the main heat exchanger 10, a circulation pump 11 that is provided
in the circulation passage 4 on the upstream side of the main heat
exchanger 10, and so on. The combustion unit 2 mixes fuel gas with
air and combusts the resulting mixture. And the main heat exchanger
10 applies heat to the room heating medium by exchanging heat
between the combustion gases generated by the combustion unit 2 and
the room heating medium.
[0027] Moreover the heating device with hot water supply function 1
comprises a bypass passage (a first bypass passage) 12, a secondary
heat exchanger 20 that is provided in the first bypass passage 12
for supplying hot water, a cold water supply passage 19, a hot
water supply passage 21, and so on. The first bypass passage 12
branches off from the circulation passage 4 at the downstream side
of the main heat exchanger 10 so as to bypass the room heating
apparatus, and joins back to the circulation passage 4 at the
upstream side of the circulation pump 11. The cold water supply
passage 19 supplies cold water to the secondary heat exchanger 20.
And the hot water supply passage 21 supplies hot water to which
heat has been supplied by the secondary heat exchanger 20 to a hot
water supply faucet or the like.
[0028] Furthermore, the heating device with hot water supply
function 1 comprises a control unit 5, and the devices described
above and so on, including this control unit 5, are contained
inside a casing 9. The control unit 5 receives detection signals
from a temperature sensor and so on that will be described
hereinafter, and also controls room heating operation and hot water
supply operation and so on by operating the circulation pump 11, a
first distribution valve 15, and so on.
[0029] Next, the circulation passage 4 will be explained.
[0030] A first temperature sensor 13 is provided in the circulation
passage 4 between the circulation pump 11 and the main heat
exchanger 10, and a second temperature sensor 14 is provided in the
passage 4 on the downstream side of the main heat exchanger 10. The
first temperature sensor 13 detects the temperature of the room
heating medium as it flows into the main heat exchanger 10. And the
second temperature sensor 14 detects the temperature of the room
heating medium after heat has been supplied thereto by the main
heat exchanger 10.
[0031] A first distribution valve 15, which is a distribution
means, is provided at the branching portion where the first bypass
passage 12 branches off from the circulation passage 4. The first
distribution valve 15 distributes the room heating medium, to which
heat has been supplied by the main heat exchanger 10, to the
circulation passage 4 and the first bypass passage 12, and its
distribution ratio is adjustable.
[0032] A pressure relief valve 16 is provided between the main heat
exchanger 10 and the first distribution valve 15, and relieves the
pressure in the circulation passage 4. And a room heating return
temperature sensor 17 that detects the temperature of the room
heating medium as it returns from the room heating apparatus
(terminal) is provided at the upstream side of the circulation pump
11. A supplementation passage 18 for supplementing the room heating
medium is connected between the circulation pump 11 and the room
heating return temperature sensor 17.
[0033] Next, the secondary heat exchanger 20 for hot water supply
will be explained. The secondary heat exchanger 20 is a heat
exchanger of the plate type, and is provided in the first bypass
passage 12. In a plate type secondary heat exchanger 20, one or
more passages are formed between a plurality of heat exchange
plates that are laminated together. Within the secondary heat
exchanger 20, the room heating medium and cold water that is
supplied from the cold water supply passage 19 flow without mixing
together through respective passage each between heat exchange
plates that are arranged so as to oppose one another, without
mutually mixing together. Roughnesses are formed on these heat
exchange plates, in order to enhance the heat exchange efficiency
by increasing their surface areas.
[0034] Next, the cold water supply passage 19 and the hot water
supply passage 21 will be explained.
[0035] A second distribution valve 23, a flow rate adjustment valve
24, a hot water supply flow rate sensor 25, and a cold water input
temperature sensor 26 are provided in the cold water supply passage
19. The second distribution valve 23 distributes cold water to the
cold water supply passage 19 and to a hot water supply bypass
passage (a second bypass passage 22) that is branched off from the
cold water supply passage 19 at the second distribution valve 23,
and its distribution ratio can be adjusted. The second bypass
passage 22 connects the cold water supply passage 19 to the hot
water supply passage 21, so that the secondary heat exchanger 20 is
bypassed.
[0036] Accordingly, the second distribution valve constitutes a
flow adjustment means that adjusts the flow rate of the cold water
flowing in the second bypass passage 22. Moreover, the flow rate
adjustment valve 24 adjusts the flow rate of the cold water
entering the second distribution valve 23. And the hot water supply
flow rate sensor 25 detects the flow rate of the cold water that
has thus been adjusted. Furthermore, the cold water input
temperature sensor 26 detects the temperature of the cold water
entering the second distribution valve 23.
[0037] As shown in FIGS. 1 and 2, the hot water supply passage 21
comprises a passage portion 21a that connects to the secondary heat
exchanger 20 and an expanded passage portion 21b that extends from
an intermediate portion M of the hot water supply passage 21 (the
downstream end of the passage portion 21a) to the downstream end of
the hot water supply passage 21, and that is of a greater diameter
than the passage portion 21a. Accordingly, the volumetric capacity
of the hot water supply passage 21 is increased by this expanded
passage portion 21b. The downstream end of the second bypass
passage 22 joins to the expanded passage portion 21b at a junction
C. The passage portion 21a that is the portion of the cold water
supply passage more to the upstream side than the intermediate
portion M may, for example, be built as a conduit member whose
external diameter is 16 mm, while the expanded passage portion 21b
may, for example, be built as a conduit member whose external
diameter is 22.2 mm. And the second bypass passage 22 may be built
as a conduit member of smaller diameter than the conduit member
that constitutes the passage portion 21a, and may, for example, be
built as a conduit member whose external diameter is 12.8 mm. It
should be understood that these conduit members are copper tubes
with wall thickness of around 1 mm.
[0038] The downstream end E of the expanded passage portion 21b is
connected to a hot water supply fitting 21c. Thus, the hot water
supply passage 21 is connected via this hot water supply fitting
21c to a passage that leads to a hot water supply destination that
is external to the heating device with hot water supply function
1.
[0039] An output hot water temperature sensor 27 is provided to the
passage portion 21a, and serves as a temperature detection means.
This output hot water temperature sensor 27 detects the temperature
of the hot water that is outputted from the secondary heat
exchanger 20. The output hot water temperature sensor 27 and the
junction C are spaced apart from one another so that, around the
time when the hot water whose output temperature has been detected
by the output hot water temperature sensor 27 reaches the junction
C, the adjustment of the distribution ratio of the second
distribution valve 23 may be completed on the basis of the
temperature of this output hot water that has been detected.
[0040] A supplied hot water temperature sensor 28 is provided at
the downstream side end portion of the expanded passage portion
21b. This supplied hot water temperature sensor 28 detects the
supply temperature of the hot water that has resulted from mixing
together of the hot water to which heat has been applied by the
secondary heat exchanger 20 and the cold water flowing through the
second bypass passage 22.
[0041] Next, the control unit 5 will be explained.
[0042] While the details are not shown in the figures, the control
unit 5 is capable of receiving detection signals from temperature
sensors and so on that are provided within the heating device with
hot water supply function 1, and moreover is connected so as to be
capable of controlling the circulation pump 11 and the first
distribution valve 15 and so on. Furthermore, it is connected to an
operation terminal (not shown in the figure) that is provided
inside the building, so as to be capable of communicating
therewith.
[0043] Next, the operation and the beneficial effects of this
heating device with hot water supply function 1 will be
explained.
[0044] When room heating operation is started by operation of the
operation terminal, the control unit 5 combusts fuel gas in the
combustion unit 2. Moreover, the circulation pump 11 is operated
and the room heating medium is circulated, while the first
distribution valve 15 is adjusted so that the room heating medium
is only circulated through the circulation passage 4. Due to this,
heat is supplied by the heat exchanger 10 to the room heating
medium by utilizing the combustion heat produced by the combustion
unit 2. And, due to room heating operation being continued, the
room heating medium is circulated at a predetermined temperature
while heat is being supplied thereto.
[0045] And hot water supply operation is started when, due to a
faucet such as a hot water faucet or the like being opened, the hot
water supply flow rate sensor 25 detects a flow rate greater than
or equal to some predetermined flow rate. When room heating
operation is not being performed at this time, the control unit 5
causes fuel gas to be combusted in the combustion unit 2. Moreover,
along with the first distribution valve 15 being adjusted so that
the room heating medium circulates only through the first bypass
passage 12, also the circulation pump 11 is operated and the room
heating medium is circulated. Due to this, heat is supplied by the
main heat exchanger 10 to the room heating medium by utilizing the
combustion heat that is being provided by the combustion unit 2.
And the room heating medium to which heat is thus being supplied
exchanges heat with cold water in the secondary heat exchanger 20,
thus supplying heat to that cold water and warming it up.
[0046] In order to adjust the temperature of the hot water to which
heat is thus being supplied by the secondary heat exchanger 20 to
the set hot water supply temperature by mixing in cold water
thereto at a low temperature, the control unit 5 adjusts the
distribution ratio of the second distribution valve 23 on the basis
of the output hot water temperature as detected by the output hot
water temperature sensor 27, and on the basis of the hot water
supply temperature detected by the supplied hot water temperature
sensor 28 and so on. Since the junction C and the output hot water
temperature sensor 27 are separated apart from one another,
accordingly the output hot water temperature detected by the output
hot water temperature sensor 27 does not experience any influence
from the cold water which is at a low temperature. Accordingly, the
hot water to which heat has been supplied by the secondary heat
exchanger 20 and the cold water passing through the second bypass
passage 22 can be mixed together at the junction C in a ratio which
is adjusted by the second distribution valve 23 to be
appropriate.
[0047] The expanded passage portion 21b is provided in the hot
water supply passage 21 in order to increase its volumetric
capacity, and the flow speed of the hot water that is being mixed
is lowered by providing the junction C in that expanded passage
portion 21b. Due to this, the hot water supply passage 21 becomes
substantively longer, and the hot water to which heat has been
supplied and the cold water are mixed together sufficiently well in
the expanded passage portion 21b, whereby it is possible to supply
hot water at a uniform temperature. Moreover, the supplied hot
water temperature sensor 28 is able to detect the temperature of
this hot water that has been sufficiently well mixed. Accordingly,
it is possible to perform appropriate hot water supply temperature
control on the basis of the output hot water temperature, the hot
water supply temperature, and so on.
[0048] Furthermore, since the second bypass passage 22 is built as
a conduit member whose diameter is smaller even than that of the
conduit member that constitutes the passage portion 21a,
accordingly, due to the higher pressure of the water flowing in the
second bypass passage 22, it is possible to prevent reverse flow of
the hot water flowing in the expanded passage portion 21b back into
the second bypass passage 22 at the junction C. Moreover, the flow
resistance is reduced due to the provision of the expanded passage
portion 21b, and this is advantageous for providing supply of hot
water at a high flow rate, and also the flow speed is reduced,
which is advantageous from the point of view of suppressing
erosion.
[0049] On the other hand, if room heating operation is already
being performed when hot water supply operation starts, and if on
the basis of the set hot water supply temperature and the output
hot water temperature and so on the control unit 5 determines that
room heating operation and hot water supply operation can both be
performed simultaneously, then the distribution ratio of the first
distribution valve 15 is changed so that room heating operation and
hot water supply operation are both performed simultaneously.
Accordingly the convenience is enhanced, since it is possible to
employ both room heating and hot water supply at the same time. It
should be understood that, if the flow rate demanded for hot water
supply is high or the like so that the control unit 5 does not
determine that both room heating and hot water supply can be
performed simultaneously, then hot water supply operation is
preferentially performed, and, when utilization of that hot water
supply has ended, the first distribution valve 15 is adjusted and
the system returns to performing room heating operation.
[0050] Apart from the above, it would be possible for a person of
ordinary skilled in the art to implement various changes and/or
additions to the embodiment of the present invention described
above without any deviation from the gist of the present invention,
and accordingly the present invention is to be considered as
including all such variant embodiments thereof.
* * * * *