U.S. patent application number 12/919836 was filed with the patent office on 2011-01-13 for heating apparatus.
Invention is credited to Mamoru Fujii, Toshiro Fujimori, Soichiro Kato, Yukinobu Kawaoka, Tsukasa Saitou, Toshiyuki Suda, Katsuyoshi Takahashi.
Application Number | 20110005470 12/919836 |
Document ID | / |
Family ID | 41056062 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110005470 |
Kind Code |
A1 |
Kato; Soichiro ; et
al. |
January 13, 2011 |
HEATING APPARATUS
Abstract
A first flow passage (R1) in which uncombusted gas (G1) 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 is combusted, and thereby enables
flow of combustion gas (G2) resulting from such combustion, and a
second flow passage (R2) formed about the first flow passage and
enabling flow of uncombusted gas supplied through the nozzle hole
are provided. According to the present invention, the combustion
chamber in a heating apparatus that heats a liquid to be heated is
be reduced in size, the flame in the combustion chamber can be
stabilized, and energy efficiency can be improved.
Inventors: |
Kato; Soichiro;
(Yokohama-shi, JP) ; Saitou; Tsukasa;
(Kawasaki-shi, JP) ; Fujimori; Toshiro;
(Yokohama-shi, JP) ; Takahashi; Katsuyoshi;
(Tokyo, JP) ; Suda; Toshiyuki; (Tokyo, JP)
; Kawaoka; Yukinobu; (Higashihiroshima-shi, JP) ;
Fujii; Mamoru; (Chiba-shi, JP) |
Correspondence
Address: |
OSTROLENK FABER GERB & SOFFEN
1180 AVENUE OF THE AMERICAS
NEW YORK
NY
100368403
US
|
Family ID: |
41056062 |
Appl. No.: |
12/919836 |
Filed: |
March 4, 2009 |
PCT Filed: |
March 4, 2009 |
PCT NO: |
PCT/JP2009/054076 |
371 Date: |
August 27, 2010 |
Current U.S.
Class: |
122/235.14 ;
122/235.32; 165/154; 165/185 |
Current CPC
Class: |
F22B 7/02 20130101; F22B
37/101 20130101; F22B 37/12 20130101 |
Class at
Publication: |
122/235.14 ;
122/235.32; 165/185; 165/154 |
International
Class: |
F24H 1/12 20060101
F24H001/12; F24H 9/00 20060101 F24H009/00; F28F 7/00 20060101
F28F007/00; F28D 7/10 20060101 F28D007/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 4, 2008 |
JP |
2008-053901 |
Mar 4, 2008 |
JP |
2008-053903 |
Claims
1. A heating apparatus comprising 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 is combusted, and
thereby enables flow of combustion gas resulting from such
combustion, and a second flow passage enabling flow of uncombusted
gas supplied through the nozzle hole.
2. The heating apparatus according to claim 1, further comprising a
third flow passage surrounded by the first flow passage and
enabling flow of the liquid to be heated, and wherein the second
flow passage is formed about the first flow passage.
3. The heating apparatus according to claim 2, wherein the third
flow passage is configured from an inner space of a third pipe, the
first flow passage is configured from a space sandwiched by the
third pipe and the first pipe concentrically enclosing the third
pipe, and the second flow passage is configured from a space
sandwiched by the first pipe and the second pipe concentrically
enclosing the first pipe.
4. The heating apparatus according to claim 3, wherein a plurality
of fins is configured to project towards the first flow passage
from an outer peripheral face of the third pipe.
5. The heating apparatus according to claim 3, wherein the third
pipe is curved toward the first flow passage side and the second
flow passage side at a predetermined interval.
6. The heating apparatus according to claim 3 comprising the second
flow passage, the first flow passage 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.
7. The heating apparatus according to claim 6, wherein a guide
portion guides the combustion gas from the first flow passage to a
region opposite the first flow passage and being on an outer side
of the third flow passage.
8. The heating apparatus according to claim 6, wherein 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.
9. The heating apparatus according to claim 6, wherein the second
flow passage is configured from an inner space of 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 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.
10. The heating apparatus according to claim 7, wherein 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.
11. The heating apparatus according to claim 7, wherein the second
flow passage is configured from an inner space of 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 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.
Description
TECHNICAL FIELD
[0001] The present invention relates a heating apparatus for
heating a fluid to be heated. This application claims the benefit
of Japanese Patent Application 2008-053901 filed in Japan on Mar.
4, 2008 and Japanese Patent Application 2008-053903 filed in Japan
on Mar. 4, 2008, the entire disclosure of which is incorporated by
reference herein.
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).
[0003] [Patent Literature 1] Japanese Patent Application, First
Publication No. 2007-139358
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0004] 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 occurrence of combustion
outside of the combustion chamber. Furthermore a large amount of
heat is radiated to the periphery from a large combustion chamber,
and thereby results in a reduction in energy efficiency.
[0005] 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
[0006] 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.
[0007] The above configuration may form the second flow passage
about the first flow passage.
[0008] 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.
[0009] In the present invention, a third flow passage is surrounded
by the first flow passage and enables flow of a liquid to be
heated.
[0010] 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 concentrically enclosing the
first pipe are enabled.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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 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
[0018] According to the heat apparatus in the present invention,
the following excellent effects are obtained.
[0019] (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.
[0020] (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.
[0021] (3) Uncombusted gas flowing in the second flow passage is
heated by high-temperature combustion gas flowing in the first flow
passage, the heated 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
[0022] 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.
[0023] FIG. 2 is a horizontal sectional view of the schematic
configuration of the apparatus shown in FIG. 1.
[0024] FIG. 3 is a vertical sectional view of the schematic
configuration of the apparatus shown in FIG. 1.
[0025] FIG. 4 is a vertical sectional view of the schematic
configuration of the small boiler according to a second embodiment
of the present invention.
[0026] FIG. 5 is a horizontal sectional view of the schematic
configuration of the small boiler according to a third embodiment
of the present invention.
[0027] FIG. 6 is a horizontal sectional view of the schematic
configuration of the small boiler according to a fourth embodiment
of the present invention.
[0028] FIG. 7 is a perspective view of the schematic configuration
of the small boiler according to a fifth embodiment of the present
invention.
[0029] FIG. 8 is a horizontal sectional view of the schematic
configuration of the apparatus shown in FIG. 7.
[0030] FIG. 9 is a vertical sectional view of the schematic
configuration of the apparatus shown in FIG. 7.
[0031] FIG. 10 is a horizontal sectional view of the schematic
configuration of the small boiler according to a sixth embodiment
of the present invention.
[0032] FIG. 11 is a perspective view of the schematic configuration
of the apparatus shown in FIG. 10.
[0033] FIG. 12 is a horizontal sectional view of the schematic
configuration of the small boiler according to a seventh embodiment
of the present invention.
[0034] FIG. 13 is a horizontal sectional view of the schematic
configuration of the small boiler according to an eighth embodiment
of the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
[0035] 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.
First Embodiment
[0036] 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.
[0037] 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).
[0038] 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.
[0039] 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.
[0040] 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 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.
[0041] 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 B1 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 R1
(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.
[0042] 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.
[0043] 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.
[0044] 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 combustion gas G2 produced by the combustion of the uncombusted
gas G1 flows through the combustion gas flow passage R1 and is
discharged.
[0045] 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
G1.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] Water W in the water flow passage R3 is heated and
evaporated by the 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.
[0050] 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.
Second Embodiment
[0051] 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.
[0052] 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.
[0053] According to the small boiler B2 in the present embodiment
having the above 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.
Third Embodiment
[0054] 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.
[0055] 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.
[0056] 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.
Fourth Embodiment
[0057] 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.
[0058] 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.
[0059] According to the small boiler B4 in the present embodiment
that has the above 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.
[0060] 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.
[0061] 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.
[0062] 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.
[0063] 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
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. Furthermore 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.
[0064] 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.
[0065] 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.
[0066] 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 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.
[0067] 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.
[0068] 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.
[0069] 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.
[0070] 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).
[0071] 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 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 formed 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.
[0072] 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 G1 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.
[0073] 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.
Sixth Embodiment
[0074] 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.
[0075] 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.
[0076] 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 R3 and opposite the combustion gas flow passage
R1.
[0077] 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.
Seventh Embodiment
[0078] 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.
[0079] 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 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.
[0080] 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.
Eighth Embodiment
[0081] 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.
[0082] 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.
[0083] 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.
[0084] 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.
[0085] 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.
[0086] 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.
INDUSTRIAL APPLICABILITY
[0087] 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.
* * * * *