Note: Descriptions are shown in the official language in which they were submitted.
CA 02717301 2012-06-04
HEATING APPARATUS
BACKGROUND ART
[0002]
In an eating and drinking establishments, or in lodging facilities, a small
heating apparatus may be installed for the heating of water for use in bathing
or for
steaming during cooking. For example, a heating apparatus has been disclosed
which
heats water flowing in a pipe using high-temperature combustion gas produced
by
combustion of a fuel in the presence of combustion air to thereby evaporate
the water
into steam. Furthermore in addition to production of steam or hot water, the
heating
apparatus may be also used for heating of various liquids (a liquid to be
heated) (Patent
Literature 1).
[Patent Literature 1] Japanese Patent Application, First Publication No. 2007-
139358
DISCLOSURE OF THE INVENTION
[Problem to be Solved by the Invention]
[0003]
Meanwhile, in a conventional heating apparatus, a large combustion chamber
must be provided in order to maintain the time for complete combustion within
the
combustion chamber. As a result, it is not possible to sufficiently downsize
the heating
apparatus. Consequently, a stable flame can be maintained even in a small
combustion
chamber by performing combustion after heating uncombusted gas in advance
using
combustion gas. However since combustion gas has a considerably high
temperature,
there is the possibility that the uncombusted gas may undergo spontaneous
combustion
as a result of excessive heating prior to supply of the uncombusted gas to the
combustion chamber and that flame propagation may occur thereby resulting in
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CA 02717301 2010-08-31
occurrence of combustion outside of the combustion chamber. Furtheimore a
large
amount of heat is radiated to the periphery from a large combustion chamber,
and
thereby results in a reduction in energy efficiency.
[0004]
The present invention is proposed in light of the above problems, and has the
object of providing a heating apparatus for heating of a liquid to be heated
that reduces
the size of a combustion chamber, stabilizes the flame in the combustion
chamber and
thereby improves energy efficiency.
[Means for Solving the Problem]
[0005]
In order to achieve the above object, the present invention is a heating
apparatus for heating of a liquid to be heated including a first flow passage
in which
uncombusted gas that contains a combustible fuel is injected from a nozzle
hole that is
smaller than the flame quenching distance at a flow speed to thereby enable
flame
maintenance and is combusted, and thereby enables flow of combustion gas
resulting
from the combustion, and a second flow passage enabling flow of uncombusted
gas
supplied through the nozzle hole.
[0006]
The above configuration may form the second flow passage about the first flow
passage.
[0007]
According to the heating apparatus, uncombusted gas is heated by flowing
through the second flow passage formed about the first flow passage which
enables
flow of the combustion gas. In order to form the second flow passage about the
first
flow passage, the entire periphery of the second flow passage does not make
contact
with the first flow passage. Therefore a part of the heat amount transmitted
from the
combustion gas is radiated from the uncombusted gas.
[0008]
In the present invention, a third flow passage is surrounded by the first flow
passage and enables flow of a liquid to be heated.
[0009]
According to the heating apparatus above, a configuration in which the third
flow passage is formed from an inner space of a third pipe, a configuration in
which the
first flow passage is formed from a space sandwiched by the third pipe and the
first pipe
concentrically enclosing the third pipe, and a configuration in which the
second flow
passage is formed from a space sandwiched by the first pipe and the second
pipe
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concentrically enclosing the first pipe are enabled.
[0010]
In the above configuration, a plurality of fins may be provided to project
towards the first flow passage from an outer peripheral face of the third
pipe.
[0011]
In the above configuration, the third pipe is curved toward the first flow
passage side and the second flow passage side at a predetermined interval.
[0012]
A configuration is possible in which the first flow passage is formed about
the
second flow passage, and the third flow passage enables flow of the liquid to
be heated
and is formed about the first flow passage.
[0013]
According to the heating apparatus above, the first flow passage is formed
about the second flow passage that enables flow of uncombusted gas, and
combustion
gas flows in the first flow passage. Thus the uncombusted gas flowing in the
second
flow passage is heated by high-temperature combustion gas which flows in the
first
flow passage. Furthermore a stable flame is formed by injection of uncombusted
gas
from the second flow passage at a flow speed enabling maintenance of a flame
through
a nozzle hole that is set to be smaller than the flame quenching distance.
Furthermore,
the third flow passage is formed about the first flow passage which enables
combustion
of uncombusted gas by the stable flame and flow of the uncombusted gas, and
the liquid
to be heated flows in the third flow passage.
[0014]
In the above configuration, a guide portion may be provided to guide the
combustion gas from the first flow passage to a region opposite the first flow
passage
that is a region on an outer side of the third flow passage.
[0015]
In the above configuration, the second flow passage is configured from an
inner space in the second pipe, the first flow passage is configured from the
space
sandwiched by the second pipe and the first pipe that concentrically surrounds
the
second pipe, and the third flow passage is configured from the space
sandwiched by the
first pipe and the third pipe that concentrically surrounds the first pipe.
[0016]
In the above configuration, the second flow passage is configured from an
inner space in the second pipe, the third flow passage is configured from the
inner space
of a plurality of fourth pipes disposed at a distance from the second pipe
centering on
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the second pipe, and the first flow passage is configured from a space
surrounded by the
second pipe and the partitions closing the interval between the pairs of
fourth pipes and
fourth pipes.
[Effects of the Invention]
[0017]
According to the heat apparatus in the present invention, the following
excellent effects are obtained.
(1) The second passage which enables flow of the uncombusted gas is formed
about the first flow passage which enables flow of the combustion gas.
Therefore
although the entire periphery of the second flow passage does not come into
contact
with the first flow passage, a part of the heat amount transmitted from the
combustion
gas is radiated from the uncombusted gas. As a result, in addition to reduce
the size of
a combustion chamber by heating uncombusted gas, overheating of the
uncombusted
gas can be suppressed, and it is possible to form a stable flame in the
combustion
chamber. Therefore the combustion chamber in the heating apparatus that heats
the
liquid to be heated can be reduced in size and maintenance of a stable flame
in the
combustion chamber is possible.
(2) The first passage is formed about the second flow passage which enables
flow of the uncombusted gas and the combustion gas flows in the first passage.
Therefore the uncombusted gas flowing in the second passage can be heated by
the
high-temperature combustion gas flowing in the first flow passage. Furthermore
a
stable flame is formed by injection of uncombusted gas from the second flow
passage at
a flow speed enabling maintenance of a flame through a nozzle hole that is set
to be
smaller than the flame quenching distance. This stable flame enables stable
combustion even when coming into direct contact with the partition face making
contact
with the cold liquid to be heated, and enables efficient transmission of heat
to the
partition face. Furthermore the third flow passage is formed about the first
flow
passage in which the uncombusted gas is combusted by the stable flame and
enables
flow of the combustion gas, and the liquid to be heated flows in the third
flow passage.
As a result, the liquid to be heated flowing in the third flow passage is
heated by direct
heating of the third flow passage by the stable flame. Therefore in comparison
to use
of a passage for the liquid to be heated that is heated only by combustion
gas, since the
heat amount is effectively transmitted to the liquid to be heated, it is
possible to improve
the energy efficiency of the heating apparatus that heats the liquid to be
heated.
(3) Uncombusted gas flowing in the second flow passage is heated by
high-temperature combustion gas flowing in the first flow passage, the heated
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uncombusted gas is injected from the second flow passage at a flow speed
enabling
maintenance of a flame through a nozzle hole that is set to be smaller than
the flame
quenching distance, and the uncombusted gas is combusted. Since this
configuration
enables sufficient heating of the uncombusted gas by the high-temperature
combustion
gas, there is no need for a large combustion chamber to enable stable
combustion, and
therefore enables continuous combustion in the microchannels of the combustion
chamber. Therefore the combustion chamber can be downsized thereby enabling
reduction in size of the heating apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018]
FIG 1 is a perspective view showing a schematic configuration of a small
boiler according to a first embodiment of a heating apparatus of the present
invention.
FIG 2 is a horizontal sectional view of the schematic configuration of the
apparatus shown in Fig. 1.
FIG 3 is a vertical sectional view of the schematic configuration of the
apparatus shown in Fig. 1.
FIG 4 is a vertical sectional view of the schematic configuration of the small
boiler according to a second embodiment of the present invention.
FIG 5 is a horizontal sectional view of the schematic configuration of the
small
boiler according to a third embodiment of the present invention.
FIG 6 is a horizontal sectional view of the schematic configuration of the
small
boiler according to a fourth embodiment of the present invention.
FIG 7 is a perspective view of the schematic configuration of the small boiler
according to a fifth embodiment of the present invention.
FIG 8 is a horizontal sectional view of the schematic configuration of the
apparatus shown in Fig. 7.
FIG 9 is a vertical sectional view of the schematic configuration of the
apparatus shown in Fig. 7.
FIG 10 is a horizontal sectional view of the schematic configuration of the
small boiler according to a sixth embodiment of the present invention.
FIG 11 is a perspective view of the schematic configuration of the apparatus
shown in Fig. 10.
FIG. 12 is a horizontal sectional view of the schematic configuration of the
small boiler according to a seventh embodiment of the present invention.
FIG 13 is a horizontal sectional view of the schematic configuration of the
CA 02717301 2010-08-31
small boiler according to an eighth embodiment of the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
[0019]
A first embodiment of a heating apparatus according to the present invention
will be described below making reference to the figures and using an example
of a small
boiler. In the figures below, the dimensions of respective members have been
suitably
varied to a size that enables recognition of each member.
[0020]
First Embodiment
FIG 1 to FIG 3 are schematic views of a small boiler B1 according to the
present embodiment. FIG 1 is a perspective view, FIG 2 is a horizontal
sectional view,
and FIG. 3 is a vertical sectional view. As shown in these views, a small
boiler B1
according to the present embodiment has a three-layered structure in which a
first pipe 1
(first pipe), a second pipe 2 (second pipe), a third pipe 3 (third pipe) are
disposed
concentrically when viewed horizontally.
[0021]
The first pipe 1 extends in a vertical direction and the lower end 11 thereof
is
closed. A plurality of nozzle holes 12 set so that the diameter thereof is
smaller than
the flame quenching distance of the uncombusted gas is provided in a side
partition
portion near to the lower end 11. The first pipe 1 is formed from a material
that has
superior heat transmission characteristics (for example, brass or the like).
[0022]
The second pipe 2 extends vertically and concentrically surrounds the first
pipe
1. A lower end 21 thereof is closed, and in the same manner as the first pipe
1, it is
formed from a material having superior heat transmission characteristics.
[0023]
The third pipe 3 extends vertically and is inserted into the first pipe 1. A
lower end 31 thereof is closed, and in the same manner as the first pipe 1 and
the second
pipe 2, the third pipe 3 is preferably formed from a material having superior
heat
transmission characteristics.
[0024]
An inner space in the third pipe 3 forms a water flow passage R3 (third flow
passage) which enables flow of the water (liquid to be heated) W. More
specifically, in
the small boiler B1 according to the present embodiment, the water flow
passage R3 is
configured from the inner space of the third pipe 3. A water supply portion
(not
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CA 02717301 2010-08-31
shown) to supply water W to the water flow passage R3 is connected in
proximity to the
lower end of the water flow passage R3. A regulated flow amount of water W is
supplied to the water flow passage R3 by the water supply portion. Furthermore
a
discharge portion (not shown) is connected to enable discharge of steam
produced by
evaporation of water W in the water flow passage R3 in proximity to the upper
end of
the water flow passage R3. A regulated amount of steam is discharged to an
external
portion from the water flow passage R3 via the discharge portion.
[0025]
A space sandwiched by the third pipe 3 and the first pipe 1 forms a combustion
gas flow passage R1 (first flow passage) in which s combustion of uncombusted
gas G1
occurs and combustion gas G2 produced by combustion of the uncombusted gas G1
can
flow. More specifically, in the small boiler B I according to the present
embodiment,
the combustion gas flow passage R1 is configured from a space sandwiched by
the third
pipe 3 and the first pipe 1 that concentrically surrounds the third pipe.
Furthermore the
water flow passage R3 is surrounded by the combustion gas flow passage R1. A
section near to the lower end of the combustion gas flow passage RI (near to
the nozzle
hole 12) forms a combustion chamber K in which uncombusted gas G1 injected
from
the nozzle holes 12 is combusted. An ignition apparatus (not shown) is
provided in the
combustion chamber K.
[0026]
A space sandwiched by the first pipe 1 and the second pipe 2 forms the
uncombusted gas flow passage R2 (second flow passage) that enables flow of
uncombusted gas G1 including combustible fuel. More specifically, the
uncombusted
gas flow passage R2 is configured from a space sandwiched by the first pipe 1
and the
second pipe 2 that concentrically covers the first pipe 1. The upper end
portion of the
second pipe 2 is connected to an uncombusted gas supply apparatus (not shown)
that
supplies uncombusted gas G1 to the uncombusted gas flow passage R2.
[0027]
The uncombusted gas G1 may be a mixed gas of fuel with an oxidation agent.
The fuel may be an oil fuel, natural gas or the like.
[0028]
In the small boiler B1 according to the present embodiment, firstly
uncombusted gas G1 is supplied from the uncombusted gas supply apparatus that
is
connected to the second pipe 2 to the uncombusted gas flow passage R2. The
uncombusted gas G1 injected from nozzle holes 12 formed in the first pipe 1 is
ignited
and combusted to thereby form a flame in the combustion chamber K. Then the
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CA 02717301 2010-08-31
combustion gas G2 produced by the combustion of the uncombusted gas G1 flows
through the combustion gas flow passage R1 and is discharged.
[0029]
When a flame is formed in the combustion chamber K, since high-temperature
combustion gas G2 flows into the combustion gas flow passage R1, the
uncombusted
gas G1 flowing through the uncombusted gas flow passage R2 becomes heated.
More
specifically, the heat amount of the combustion gas G2 is transmitted to the
uncombusted gas G1 through the first pipe 1 that functions as a heat-
exchanging
partition to thereby heat the uncombusted gas Gl.
[0030]
The uncombusted gas G1 heated by heat exchange with the combustion gas G2
is injected in a heated state into an inner portion of the first pipe 1
through the nozzle
holes 12. The uncombusted gas G1 is injected from the nozzle holes 12 and
combusted in the combustion chamber K.
[0031]
Since the nozzle holes 12 formed in the first pipe 1 are set to be smaller
than
the flame quenching distance of the uncombusted gas G1 in the combustion
environment of the combustion chamber K, it is possible to suppress
propagation of the
flame to the uncombusted gas flow passage R2. Furthermore since the
uncombusted
gas flow passage R2 is formed about the combustion gas flow passage R1, the
entire
periphery of the uncombusted gas flow passage R2 does not come into contact
with the
combustion gas flow passage R1, and a part of the heat amount transmitted from
the
combustion gas G2 is radiated from the uncombusted gas G1. As a result,
overheating
of the uncombusted gas G1 can be suppressed, and therefore propagation of the
flame to
the uncombusted gas flow passage R2, and spontaneous combustion of the
uncombusted gas G1 can be suppressed. As a result, the flame in the combustion
chamber K is stable and combustion can be continuously executed.
[0032]
As described above, uncombusted gas G1 supplied to the combustion chamber
K through the uncombusted gas flow passage R2 is heated by the combustion gas
G2
flowing through the combustion gas flow passage R1 in a state in which
combustion in
the combustion chamber K is continuously executed. Therefore, a stable flame
can be
formed by a combustion chamber K which is extremely small in comparison to the
combustion chamber in a conventional heating apparatus.
[0033]
Water W in the water flow passage R3 is heated and evaporated by the
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combustion gas G2 in the combustion gas flow passage R2 and the flame in the
combustion chamber K in a state in which a stable flame is formed in the
combustion
chamber K and combustion is continuously executed. More specifically, heat
produced by combustion is transmitted to water W through the second pipe 2
that
functions as a heat exchange partition, and therefore the water W is heated
and
evaporates. The steam produced by evaporation of the water W is discharged to
an
external portion of the small boiler B1 through the discharge portion (not
shown).
Since the water flow passage R3 is surrounded by the combustion gas flow
passage R1,
a heat amount can be transmitted to the water W from the entire periphery of
the water
flow passage R3 and thereby enables efficient heating of the water W.
[0034]
According to the small boiler B1 of the present embodiment, an uncombusted
gas flow passage R2 which enables flow of the uncombusted gas G1 is formed
about the
combustion gas flow passage R1 which enables flow of the combustion gas G2.
Consequently, the entire periphery of the uncombusted gas flow passage R2
makes no
contact with the combustion gas flow passage R1, and a portion of the heat
amount
transmitted from the combustion gas G2 is radiated from the uncombusted gas
G1. As
a result, the combustion chamber K can be made smaller due to the heating of
the
uncombusted gas G1, and it is possible to suppress the overheating of the
uncombusted
gas G1 and stabilize the flame in the combustion chamber K. Therefore the
combustion chamber K can be made smaller and the flame in the combustion
chamber
K can be stabilized.
[0035]
Second Embodiment
Next, a second embodiment of the present invention will be described. In the
description of the second embodiment, description of those sections which are
the same
as the first embodiment will be omitted or simplified.
[0036]
FIG 4 is a vertical sectional view of the schematic configuration of a small
boiler B2 according to an embodiment. As shown in the figure, the small boiler
B2
according to the present embodiment includes a fourth pipe 4 which
concentrically
surrounds the second pipe 2. A space sandwiched by the second pipe 2 and the
fourth
pipe 4 is formed as a storage portion 5 that stores water W and is connected
to the water
flow passage R3.
[0037]
According to the small boiler B2 in the present embodiment having the above
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configuration, although water W stored temporarily in the water storage
portion 5 is
supplied to the water flow passage R3, the water W receives a portion of the
heat
amount radiated from the uncombusted gas G1 in the storage portion 5.
Consequently,
the amount of heat radiated from the uncombusted gas G1 can be used to heat
the water
W, and therefore enables more efficient heating of the water W.
[0038]
Third Embodiment
Next, a third embodiment of the present invention will be described. In the
description of the third embodiment, description of those sections which are
the same as
the first embodiment will be omitted or simplified.
[0039]
FIG. 5 is a horizontal sectional view of the schematic configuration of a
small
boiler B3 according to an embodiment. As shown in the figure, the small boiler
B3
according to the present embodiment includes a plurality of fins 10 that
project towards
the combustion gas flow passage R1 from an outer peripheral face of the third
pipe 3.
The fins 10 are integrally formed with the third pipe 3 and are formed from a
material
having superior heat transmission characteristics in the same manner as the
third pipe 3.
[0040]
According to the small boiler B3 in the present embodiment that has the above
configuration, the fins 10 enable an increase in the heat exchanging surface
area with
water W flowing through the water flow passage R3 and the combustion gas G2
flowing
through the combustion gas flow passage R1, and thereby enable more efficient
heating
of the water.
[0041]
Fourth Embodiment
Next, a fourth embodiment of the present invention will be described. In the
description of the fourth embodiment, description of those sections which are
the same
as the first embodiment will be omitted or simplified.
[0042]
FIG. 7 is a horizontal sectional view of the schematic configuration of a
small
boiler B4 according to an embodiment. As shown in the figure, the small boiler
B4
according to the present embodiment is such that the second pipe 2 is
configured in a
star shape that is curved toward the combustion gas flow passage R1 and the
water flow
passage R3 at a fixed interval.
[0043]
According to the small boiler B4 in the present embodiment that has the above
CA 02717301 2010-08-31
configuration, the formation of the third pipe 3 into a star shape which is
curved at a
fixed interval enables an increase in the heat exchanging surface area with
water W
flowing through the water flow passage R3 and the combustion gas G2 flowing
through
the combustion gas flow passage R1, and thereby enables more efficient heating
of the
water.
[0044]
FIG 7 to FIG. 9 are schematic views of a small boiler B101 according to a
fifth
embodiment of the present invention. FIG 7 is a perspective view, FIG 8 is a
horizontal sectional view, and FIG. 9 is a vertical sectional view. As shown
in these
views, a small boiler B101 according to the present embodiment has a three-
layered
structure in which a first pipe 101 (first pipe), a second pipe 102 (second
pipe), a third
pipe 103 (third pipe) are disposed concentrically when viewed horizontally.
[0045]
The second pipe 102 extends vertically and a lower end 111 thereof is closed.
A plurality of nozzle holes 112 set so that the diameter thereof is smaller
than the flame
quenching distance of the uncombusted gas is provided in a side partition
portion near
to the lower end 111. The second pipe 102 is formed from a material that has
superior
heat transmission characteristics (for example, brass or the like). The inner
space in
the second pipe 102 forms an uncombusted gas flow passage R2 (second flow
passage)
which enables flow of the uncombusted gas G1 including combustible fuel. More
specifically, in the small boiler B101 according to the present embodiment,
the
uncombusted gas flow passage R2 is configured from the inner space of the
second pipe
102. An upper end portion of the second pipe 102 is connected to the
uncombusted
gas supply passage (not shown) that supplies uncombusted gas G1 to the
uncombusted
gas flow passage R2.
[0046]
The uncombusted gas G1 may be a mixture gas of fuel with an oxidation
agent. The fuel may be an oil fuel, natural gas or the like.
[0047]
The first pipe 101 extends vertically and is disposed to concentrically
surround
the second pipe 102. A lower end 121 thereof is closed, and in the same manner
as the
second pipe 102, it is formed from a material displaying superior heat
transmission
characteristics. A space sandwiched by the first pipe 101 and the second pipe
102
forms a combustion gas flow passage R1 (first flow passage) which enables
combustion
of uncombusted gas G1 and enables flow of the combustion gas G2 produced by
the
combustion of uncombusted gas G1. More specifically, in the small boiler B101
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according to the present embodiment, the combustion gas flow passage R1 is
configured
from a space sandwiched by the second pipe 2 and the first pipe 101 that
concentrically
surrounds the second pipe 2. Furtheimore a section near to the lower end of
the
combustion gas flow passage R1 (near to the nozzle hole 112) forms a
combustion
chamber K in which uncombusted gas G1 injected from the nozzle holes 112 is
combusted. An ignition apparatus (not shown) is provided in the combustion
chamber
K.
[0048]
The third pipe 103 extends vertically and is disposed to concentrically
surround
the first pipe 101. A lower end 131 thereof is closed, and it is preferred
that the third
pipe 3 is formed from a material displaying low heat transmission
characteristics. A
space sandwiched by the first pipe 101 and the third pipe 103 forms a water
flow
passage R3 (third flow passage) which enables flow of the water (liquid to be
heated) W.
More specifically, in the small boiler B101 according to the present
embodiment, the
water flow passage R3 is configured from a space sandwiched by the first pipe
101 and
the third pipe 103 that concentrically surrounds the first pipe 101.
Furthermore, a
water supply portion (not shown) for supplying water to the water flow passage
R3 is
connected to a section near to the lower end of the water flow passage R3, and
a
regulated flow amount of water W is supplied to the water flow passage R3 by
the water
supply portion. Furthermore a discharge portion (not shown) for discharging
steam
produced by evaporation of water W in the water flow passage R3 is connected
in
proximity to an upper end of the water flow passage R3, and a regulated flow
amount of
steam is discharged from the water flow passage R3 to an external portion by
the
discharge portion.
[0049]
In a small boiler B101 according to the present embodiment having the above
configuration, firstly uncombusted gas G1 is supplied from the uncombusted gas
supply
apparatus that is connected to the second pipe 102 to the uncombusted gas flow
passage
R2. The uncombusted gas G1 injected from nozzle holes 112 formed in the second
pipe 102 is ignited and combusted to thereby form a flame in the combustion
chamber
K. Then the
combustion gas G2 produced by the combustion of the uncombusted gas
G1 flows through the combustion gas flow passage R1 and is discharged.
[0050]
When a flame is formed in the combustion chamber K, since high-temperature
combustion gas G2 flows into the combustion gas flow passage R1 formed about
the
uncombusted gas flow passage R2, the uncombusted gas G1 flowing through the
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uncombusted gas flow passage R2 becomes heated. More specifically, the heat
amount of the combustion gas G2 is transmitted to the uncombusted gas G1
through the
second pipe 102 that functions as a heat-exchanging partition to thereby heat
the
uncombusted gas G1.
[0051]
The uncombusted gas G1 heated by heat exchange with the combustion gas G2
is ejected into an outer portion of the second pipe 102 through the nozzle
holes 112 in a
state of being heated to almost an ignition temperature. The uncombusted gas
G1
ejected from the nozzle holes 112 is ignited by the flame formed in the
combustion
chamber K, and is combusted.
[0052]
Since the nozzle holes 112 formed in the second pipe 102 are set to be smaller
than the flame quenching distance of the uncombusted gas G1 in the combustion
environment of the combustion chamber K, the flame does not propagate to the
uncombusted gas flow passage R2. Consequently the flame is stabilized in the
combustion chamber K, and thereby enables continuous combustion.
[0053]
As described above, uncombusted gas G1 supplied to the combustion chamber
K through the uncombusted gas flow passage R2 is heated by the combustion gas
G2
flowing through the combustion gas flow passage R1 in a state in which
combustion in
the combustion chamber K is continuously executed. Therefore, a stable flame
can be
formed by a combustion chamber K which is extremely small in comparison to the
combustion chamber in a conventional heating apparatus.
[0054]
Water W in the water flow passage R3 is heated and evaporated by the
combustion gas G2 in the combustion gas flow passage R1 and the flame in the
combustion chamber K in a state in which a stable flame is formed in the
combustion
chamber K and combustion is continuously executed. More specifically, a heat
amount of the flame and a heat amount of the combustion gas G2 are transmitted
to the
water W through the first pipe 101 that functions as a heat exchange
partition, and
therefore the water W is heated and evaporated. The steam produced by
evaporation
of the water W is discharged to an external portion of the small boiler B101
through the
discharge portion (not shown).
[0055]
According to the small boiler B101 of the present embodiment, a combustion
gas flow passage R1 in which combustion gas G2 flows is formed about the
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uncombusted gas flow passage R2 which enables flow of the uncombusted gas G1.
Consequently, the uncombusted gas G1 flowing in the uncombusted gas flow
passage
R2 is heated by the combustion gas G2 that flows in the combustion gas flow
passage
R1. Furthermore a stable flame is fonned by injection of uncombusted gas G1
from
the uncombusted gas flow passage R2 at a flow speed enabling maintenance of a
flame
through a nozzle holes 112 that are set to be smaller than the flame quenching
distance.
This stable flame is enabled even when coming into direct contact with the
partition
face (first pipe 101) making contact with the cold liquid. Furthermore the
water flow
passage R3 is formed about the combustion gas flow passage R1 which forms the
stable
flame and water W is supplied to the water flow passage R3. As a result, the
water W
that flows in the third flow passage is heated by direct heating of the water
flow passage
R3 by the stable flame. Therefore in comparison to heating the water flow
passage R3
only by combustion gas G2, the amount of heat can be efficiently transmitted
to the
water W. Consequently, the small boiler B101 of the present embodiment enables
an
improvement in energy efficiency.
[0056]
According to the small boiler B101 of the present embodiment, since the
uncombusted gas G1 flowing in the combusted gas flow passage R2 is heated by
high-temperature combustion gas G2 flowing in the combustion gas flow passage
R1,
the heated uncombusted gas G1 is combusted by ejection from the uncombusted
gas
flow passage R2 at a flow speed enabling maintenance of a flame through a
nozzle hole
112 that is set to be smaller than the flame quenching distance. The adoption
of the
above configuration enables sufficient heating of the uncombusted gas 01 by
the
high-temperature combustion gas G2, and therefore enables continuous stable
combustion in a small combustion chamber K. Thus the combustion chamber can be
made smaller thereby enabling downsizing of the apparatus.
[0057]
Therefore according to the small boiler B101 of the present embodiment,
further downsizing of the apparatus is enabled at the same time as improvement
to
energy efficiency.
[0058]
Sixth Embodiment
Next, a sixth embodiment of the present invention will be described. In the
description of the sixth embodiment, description of those sections which are
the same as
the fifth embodiment will be omitted or simplified.
[0059]
14
CA 02717301 2010-08-31
FIG 10 and FIG 11 are schematic views of a small boiler B102 according to a
fifth embodiment of the present invention. FIG. 10 is a horizontal sectional
view and
FIG. 11 is a perspective view. As shown in these views, the uncombusted gas
flow
passage R2 of the small boiler B102 according to the present embodiment is
configured
from an inner space in the second pipe 102 in the same manner as the small
boiler B101
in the fifth embodiment. The water flow passage R3 is configured from the
inner
space of a plurality of fourth pipes 104 disposed at a distance from the
second pipe 102
centering on the second pipe 102, and the combustion gas flow passage R1 is
configured from a space surrounded by partitions 105 closing the second pipe
102 and
the space between the pairs of fourth pipes 104 and fourth pipes 104.
[0060]
As shown in Fig. 11, the height of the partition 105 is set to be low in
comparison with the height of the second pipe 102 and the fourth pipe 104. As
a result,
at the upper portion of the small boiler B102, there is a space between the
pairs of
fourth pipes 104. Thus the space functions as a guide portion 106 for guiding
the
combustion gas G2 into a region on an outer side of the water flow passage
R3and
opposite the combustion gas flow passage R1.
[0061]
In the same manner as the fifth embodiment, in the small boiler B102
according to the present embodiment as configured above, uncombusted gas G1
heated
by heat exchange with the combustion gas G2 is ejected into the combustion gas
flow
passage R1 and combusted. When combustion gas G2 is newly produced, a portion
of
that combustion gas G2 is circulated to the rear side (the opposite side to
the
combustion gas passage R1) of the fourth pipe 104 through the guide portion
106.
Thus, the entire periphery of the fourth pipe 104 can be heated by the
combustion gas
G2 and thereby enables more efficient heating of the water W. Therefore energy
efficiency can be further improved.
[0062]
Seventh Embodiment
Next, a seventh embodiment of the present invention will be described. In the
description of the seventh embodiment, description of those sections which are
the same
as the fifth embodiment will be omitted or simplified.
[0063]
FIG 12 is a horizontal sectional view of the schematic configuration of a
small
boiler according to a seventh embodiment of the present invention. As shown in
these
views, the small boiler B103 according to the present embodiment includes a
plurality
CA 02717301 2010-08-31
of fins 110 that project towards the water flow passage R3 from an outer
peripheral face
of the first pipe 101. The fins 110 are integrally formed with the first pipe
101 and are
formed from a material having superior heat transmission characteristics in
the same
manner as the first pipe 101.
[0064]
According to the small boiler B103 in the present embodiment that has the
above configuration, the fins 110 enable an increase in the heat exchanging
surface area
with water W flowing through the water flow passage R3 and the combustion gas
G2
flowing through the combustion gas flow passage R1, and thereby enable more
efficient
heating of the water. Therefore energy efficiency can be further improved.
[0065]
Eighth Embodiment
Next, an eighth embodiment of the present invention will be described. In the
description of the eighth embodiment, description of those sections which are
the same
as the fifth embodiment will be omitted or simplified.
[0066]
FIG 13 is a horizontal sectional view of the schematic configuration of a
small
boiler B104 according to the present embodiment. As shown in the figure, the
small
boiler B104 according to the present embodiment is such that the first pipe 1
is
configured in a star shape that is curved toward the combustion gas flow
passage R1
and the water flow passage R3 at a fixed interval.
[0067]
According to the small boiler B104 in the present embodiment that has the
above configuration, the formation of the first pipe 101 into a star shape
which is curved
at a fixed interval enables an increase in the heat exchanging surface area
with water W
flowing through the water flow passage R3 and the combustion gas G2 flowing
through
the combustion gas flow passage R1, and thereby enables more efficient heating
of the
water.
[0068]
Although the preferred embodiments of the heat apparatus according to the
present invention have been described above making reference to the attached
figures,
the present invention, of course, is not limited to the above embodiments. The
shape
or combination of each constitutive member shown in the embodiments above is
merely
exemplary, and various modifications based on design requirements are possible
within
a scope that does not depart from the spirit of the invention.
[0069]
16
CA 02717301 2010-08-31
For example, in the above embodiments, a small boiler was described as an
example of a heating apparatus. However the present invention is not limited
in this
regard, and may be applied to a boiling apparatus for heating water for the
purpose of
making hot water, or to an apparatus heating oil or gas. Furthermore the
present
invention may be applied to a large boiler, or to industrial product such as a
fluidized-bed boiler using a heated powder material. Furthermore when the
heating
apparatus according to the present invention is applied to a recycling
fluidized-bed
boiler, the particle material may be transported using combustion gas.
[0070]
In the first to the eighth embodiments above, the external shape and sectional
shape of the first pipe 1 and 101, the second pipe 2 and 102, the third pipe 3
and 103,
and the fourth pipe 4 and 104 are merely exemplary, and may be configured in
an
arbitrary manner.
[0071]
[Industrial Applicability]
According to the present invention, a heating apparatus for heating a liquid
to
be heated enables stabilization of a flame in a combustion chamber and
downsizing of
the combustion chamber, in addition to improving energy efficiency.
17
