U.S. patent application number 09/760726 was filed with the patent office on 2001-07-19 for intermediate fluid type vaporizer.
This patent application is currently assigned to Kabushiki Kaisha Kobe Seiko Sho.. Invention is credited to Asada, Kazuhiko, Iwasaki, Masahide.
Application Number | 20010008126 09/760726 |
Document ID | / |
Family ID | 18541415 |
Filed Date | 2001-07-19 |
United States Patent
Application |
20010008126 |
Kind Code |
A1 |
Iwasaki, Masahide ; et
al. |
July 19, 2001 |
Intermediate fluid type vaporizer
Abstract
An intermediate fluid type vaporizer is provided which employs a
heat source fluid capable of providing a relatively large
temperature difference utilizable for vaporization, and which can
make an overall size of the vaporizer more compact. The
intermediate fluid type vaporizer comprises an intermediate fluid
evaporator constructed by providing heat source tubes in a shell,
which contains an intermediate fluid therein, to evaporate the
intermediate fluid of liquid phase with heat exchange between the
heat source fluid and the liquid intermediate fluid, and a
liquefied gas evaporator constructed by providing heat transfer
tubes in the shell to evaporate liquefied gas with heat exchange
between the liquefied gas and the evaporated intermediate fluid.
The heat source tubes are formed by straight tubes arranged so as
to constitute two or more passes.
Inventors: |
Iwasaki, Masahide;
(Takasago-shi, JP) ; Asada, Kazuhiko;
(Takasago-shi, JP) |
Correspondence
Address: |
REED SMITH HAZEL & THOMAS
Suite 1400
3110 Fairview Park Drive
Falls Church
VA
22042
US
|
Assignee: |
Kabushiki Kaisha Kobe Seiko
Sho.
|
Family ID: |
18541415 |
Appl. No.: |
09/760726 |
Filed: |
January 17, 2001 |
Current U.S.
Class: |
122/31.1 |
Current CPC
Class: |
F17C 2221/033 20130101;
F17C 2225/0123 20130101; F28D 2021/0064 20130101; F17C 2227/0318
20130101; F17C 2227/0323 20130101; F17C 2205/018 20130101; F17C
2227/0393 20130101; F17C 2265/05 20130101; F17C 7/04 20130101; F17C
2223/0161 20130101; F28D 15/02 20130101; F17C 2223/033 20130101;
F17C 2221/014 20130101; F17C 2221/011 20130101 |
Class at
Publication: |
122/31.1 |
International
Class: |
F22B 001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 18, 2000 |
JP |
2000-013884 |
Claims
What is claimed is:
1. An intermediate fluid type vaporizer comprising: a shell
containing an intermediate fluid therein; heat source tubed formed
by a plurality of straight tubes, which are provided in said shell,
and allowing a heat source fluid to flow through said heat source
tubes for evaporating the intermediate fluid of liquid phase with
heat exchange between the heat source fluid and the liquid
intermediate fluid; a return chamber connecting said plurality of
straight tubes to each other at ends thereof; and heat transfer
tubes provided in said shell and allowing liquefied gas to be
introduced to and flow through said heat transfer tube for heat
exchange between the evaporated intermediate fluid and the
liquefied gas.
2. An intermediate fluid type vaporizer according to claim 1,
wherein said heat source tubes are formed by an even number of
straight tubes.
3. An intermediate fluid type vaporizer according to claim 1,
further comprising a gas heater for heating gas discharged from
said heat transfer tubes with heat exchange effected between the
discharged gas and the heat source fluid before being supplied to
said heat source tube.
4. An intermediate fluid type vaporizer according to claim 3,
wherein said gas heater is installed independently of said
shell.
5. An intermediate fluid type vaporizer according to claim 3,
wherein said gas heater is installed on said shell.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an intermediate fluid type
vaporizer for heating and vaporizing a low temperature liquid, such
as liquefied natural gas (hereinafter referred to as "LNG"), by
using an intermediate fluid such as propane.
[0003] 2. Description of the Related Art
[0004] Hitherto, an intermediate fluid type vaporizer using an
intermediate fluid in addition to a heat source fluid is known as
means for continuously vaporizing a low temperature liquid, such as
LNG, with a compact structure (see, e.g., Japanese Unexamined
Patent Application Publication No. 53-5207).
[0005] FIG. 6 shows one example of such an intermediate fluid type
vaporizer for LNG. This conventional vaporizer comprises an
intermediate fluid evaporator E1, an LNG evaporator E2, and a
natural gas (hereinafter referred to as "NG") heater E3.
[0006] The intermediate fluid evaporator E1 comprises a first shell
101, an outlet chamber 102 formed at one end of the first shell
101, an intermediate chamber 103 formed at the other end of the
first shell 101, and a large number of heat source tubes 104
disposed in a lower portion of an inner space of the first shell
101 and extending between both the chambers 102, 103. The first
shell 101 contains therein an intermediate fluid (e.g., propane)
having a boiling point lower than that of sea water as a heat
source fluid. The LNG evaporator E2 comprises an inlet chamber 111
and an outlet chamber 112 divided from each other by a partition
wall 110, and a large number of heat transfer tubes 113 for
communicating both the chambers 111 and 112 with each other. Each
of the heat transfer tubes 113 has a substantially U-shape and
projects into an upper portion of the inner space of the first
shell 101. The NG heater E3 comprises a second shell 120 provided
in continuation with the intermediate chamber 103, an inlet chamber
121, and a large number of heat source tubes 122 extending between
both the chambers 103, 121.
[0007] A heat source fluid (sea water in the illustrated related
art) flows through the inlet chamber 121, the large number of heat
source tubes 122, the intermediate chamber 103, the large number of
heat source tubes 104, and the outlet chamber 102 successively in
the order named. Of this route, the heat source tubes 122 are
disposed in the NG heater E3 and the heat source tubes 104 are
disposed in the intermediate fluid evaporator E1. The outlet
chamber 112 of the LNG evaporator E2 is connected to the second
shell 120 side of the NG heater E3 through an NG conduit 123.
[0008] In such a vaporizer, sea water as a heat source fluid flows
into the outlet chamber 102 after passing through the inlet chamber
121, the heat source tubes 122, the intermediate chamber 103, and
the heat source tubes 104. While passing through the heat source
tubes 104, the sea water is subjected to heat exchange with the
intermediate fluid 105 of liquid phase in the intermediate fluid
evaporator E1, thereby evaporating the liquid intermediate fluid
105. On the other hand, LNG to be vaporized is introduced to the
heat transfer tubes 113 through the inlet chamber 111. The
evaporated intermediate fluid 105 condenses with heat exchange
between the LNG in the heat transfer tubes 113 and the intermediate
fluid 105 of gaseous phase in the intermediate fluid evaporator E1.
By receiving heat generated upon condensation of the gaseous
intermediate fluid 105, the LNG evaporates and becomes NG in the
heat transfer tubes 113. The produced NG is introduced to the NG
heater E3 from the outlet chamber 112 through the NG conduit 123,
and is further heated with heat exchange between the NG and the sea
water flowing through the heat source tubes 122 in the NG heater
E3. Thereafter, the NG is supplied to consumers.
[0009] With the intermediate fluid type LNG vaporizer having the
above-described construction, LNG can be continuously vaporized
through repeated evaporation and condensation of the intermediate
fluid 105.
[0010] In most of intermediate fluid type vaporizers that have been
conventionally used, the heat source fluid is sea water. In some of
stations employing intermediate fluid type vaporizers, however,
another heat source fluid such as warm water or an aqueous solution
of glycol has become used in a place where sea water cannot be used
from the standpoint of environmental protection, or in the case
where sea water is not used to combine the cold heat recovery
system.
[0011] In a conventional intermediate fluid type vaporizer using
sea water as a heat source, a temperature difference obtainable
with sea water as a heat source for vaporization is in the range of
5-7.degree. C. Meanwhile, in an intermediate fluid type vaporizer
using another heat source fluid such as warm water or an aqueous
solution of glycol instead of sea water, a relatively large
temperature difference of about 20.degree. C. can be utilized for
vaporization.
[0012] In the latter vaporizer, therefore, a flow rate of the heat
source can be reduced. However, the heat transfer efficiency is
deteriorated because a flow speed of the heat source flowing
through the heat source tubes 104 in the intermediate fluid
evaporator E1 and the heat source tubes 122 in the NG heater E3
cannot be set to a sufficiently high value. Thus, it has been found
that, in order to compensate for such a deterioration of the heat
transfer efficiency, the overall size of an intermediate fluid type
vaporizer must be enlarged, and the cost of a heat exchanger is
increased.
[0013] One conceivable method for increasing a flow speed of the
heat source in the heat source tubes is to reduce the number of the
heat source tubes 104 in the intermediate fluid evaporator E1 and
the number of the heat source tubes 122 in the NG heater E3.
However, reducing the number of the heat source tubes decreases a
heat transfer area and hence gives rise to another necessity of
increasing the lengths of the heat source tubes 104 in the
intermediate fluid evaporator E1 and the heat source tubes 122 in
the NG heater E3. This means that, since the intermediate fluid
evaporator E1 and the NG heater E3 are connected to each other in
series as shown in FIG. 6, the above method requires a longer
installation area in the longitudinal direction, impedes free
layout in design due to restrictions imposed on an equipment layout
plan at a factory site, and eventually needs a larger land for
installation.
SUMMARY OF THE INVENTION
[0014] In consideration of the state of the art set forth above, it
is an object of the present invention to provide an intermediate
fluid type vaporizer which employs a heat source fluid capable of
providing a relatively large temperature difference utilizable for
vaporization, and which can make an overall size of the vaporizer
more compact.
[0015] To achieve the above object, an intermediate fluid type
vaporizer according to the present invention comprises an
intermediate fluid evaporator constructed by providing heat source
tubes in a shell, which contains an intermediate fluid therein, to
evaporate the intermediate fluid of liquid phase with heat exchange
between the heat source fluid and the liquid intermediate fluid,
and a liquefied gas evaporator constructed by providing heat
transfer tubes in the shell to evaporate liquefied gas with heat
exchange between the liquefied gas and the evaporated intermediate
fluid. The heat source tubes are formed by a plurality of straight
tubes, i.e., straight tubes arranged so as to constitute two or
more passes.
[0016] With the above features, by employing a heat source fluid
that is capable of providing a relatively large temperature
difference utilizable for vaporization, the required flow rate of
the heat source fluid can be reduced. Also, by arranging the heat
source tubes of the intermediate fluid evaporator so as to
constitute two or more passes, a flow speed of the heat source
fluid in each heat source tube can be increased, whereby the heat
transfer efficiency is enhanced and a sufficient heat transfer area
can be ensured. Therefore, a more efficient and compact heat
exchanger can be realized. Further, since the two or more passes of
the heat source tubes are constituted by the combination of
straight tubes and a return chamber rather than using U-tubes, tube
bundles can be arranged in a smaller area, thus resulting in a
smaller diameter of the shell and a more compact structure of the
vaporizer.
[0017] Preferably, the heat source tubes are formed by bundles of
straight tubes arranged between tube plates provided at opposite
ends of the shell such that the tube bundles are extended to go and
return between the tube plates while constituting an even number of
passes not less than two. With this feature, inlet and outlet
chambers for the heat source fluid can be arranged at one end of
the shell, and a return chamber can be arranged at the other end of
the shell. As a result, the inlet and outlet chambers for the heat
source fluid can be arranged closer to each other.
[0018] Preferably, the intermediate fluid type vaporizer further
comprises a gas heater for heating gas discharged from the
liquefied gas evaporator with heat exchange effected between the
discharged gas and the heat source fluid supplied to the
intermediate fluid evaporator. In this case, the gas heater can be
installed independently of the intermediate fluid evaporator and
the liquefied gas evaporator.
[0019] More specifically, by arranging the heat source tubes of the
intermediate fluid evaporator so as to constitute two or more
passes, the heat source tubes of the intermediate fluid evaporator
are no longer necessarily arranged in series with respect to the
heat source tubes of the gas heater. For this reason, the gas
heater can be installed as a separate unit independent of the
intermediate fluid evaporator and the liquefied gas evaporator.
Therefore, the diameter and length of a shell of the gas heater can
be set as appropriate without undergoing limitations imposed by the
diameter and length of the shell that is in common to both the
intermediate fluid evaporator and the liquefied gas evaporator.
Consequently, equipment layout of the vaporizer can be more freely
designed.
[0020] The gas heater is preferably mounted on the shell. This
arrangement enables an overall installation area of the vaporizer
to be cut down.
[0021] Thus, since the intermediate fluid type vaporizer of the
present invention employs the heat source fluid capable of
providing a relatively large temperature difference utilizable for
vaporization and is constructed with a more efficient and compact
structure, it can be suitably used for efficiently vaporizing
liquefied natural gas into natural gas and supplying the natural
gas to consumers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a front sectional view of principal part of an
intermediate fluid type vaporizer according to one embodiment of
the present invention;
[0023] FIG. 2 is a sectional view taken along line II-II in FIG.
1;
[0024] FIG. 3 is a sectional view taken along line III-III in FIG.
1;
[0025] FIG. 4 is a front view showing one example of equipment
layout of the intermediate fluid type vaporizer according to the
present invention;
[0026] FIG. 5 is a front view showing another example of equipment
layout of the intermediate fluid type vaporizer according to the
present invention; and
[0027] FIG. 6 is a front sectional view of principal part of a
conventional intermediate fluid type vaporizer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] An intermediate fluid type vaporizer according to one
embodiment of the present invention will be described below with
reference to the drawings. FIG. 1 is a front sectional view of
principal part of the intermediate fluid type vaporizer according
to one embodiment of the present invention, FIG. 2 is a sectional
view taken along line II-II in FIG. 1, and FIG. 3 is a sectional
view taken along line III-III in FIG. 1.
[0029] The intermediate fluid type vaporizer shown in FIG. 1 is
suitable for vaporizing LNG by using a heat source fluid, such as
warm water or an aqueous solution of glycol, which can provide a
relatively large temperature difference utilizable for vaporization
of the LNG. The vaporizer comprises an intermediate fluid
evaporator E1, an LNG evaporator E2, and an NG heater E3.
[0030] The intermediate fluid evaporator E1 comprises a shell 1, a
large number of 2-pass heat source tubes 2 provided in a lower
portion of an inner space of the shell 1, a heat source inlet
chamber 3 and a heat source outlet chamber 4 both provided at one
end of the shell 1, and a return chamber 5 provided at the other
end of the shell 1.
[0031] Each of the heat source tubes 2 has opposite ends fixed to
and penetrating through tube plates 7, 8 at both the ends of the
shell 1, respectively, and it is in the form of a straight tube. As
more clearly shown in FIG. 2, the heat source tubes 2 are made up
of a first tube bundle 11 forming a first pass and a second tube
bundle 12 forming a second pass. The heat source fluid flows
through the first tube bundle 11 from the heat source inlet chamber
3 to the return chamber 5, and the heat source fluid flows through
the second tube bundle 12 from the return chamber 5 to the heat
source outlet chamber 4. Since the heat source tubes 2 are each in
the form of a straight tube, a spacing L between the first tube
bundle 11 and the second tube bundle 12 can be minimized so that
the diameter of the shell 1 is reduced. If U-tubes are used as the
heat source tubes 2, the spacing L would be increased and so would
be the diameter of the shell 1 because of a necessary minimum
bending radius of the U-tubes. An intermediate fluid 9 is contained
in the shell 1, and the heat source tubes 2 are situated in the
intermediate fluid 9 of liquid phase. As more clearly shown in FIG.
3, the heat source inlet chamber 3 and the heat source outlet
chamber 4 are divided from each other by a partition wall 6.
[0032] By so arranging the heat source tube bundle on the inlet
side and the heat source tube bundle on the outlet side to separate
from each other horizontally, a convection within the shell can be
accelerated due to a temperature difference between the heat source
tube bundles on both the inlet and outlet sides. The accelerated
convection causes vapor of the intermediate fluid to uniformly
spread over the entire inner space of the shell, and hence enables
heat exchange to be efficiently performed at heat transfer
tubes.
[0033] The LNG evaporator E2 comprises the same shell 1 as
constituting the intermediate fluid evaporator E1, an inlet chamber
22 and an outlet chamber 23 divided from each other by a partition
wall 21, and a large number of heat transfer tubes 24 for
communicating both the chambers 22, 23 with each other. As more
clearly shown in FIG. 2, the heat transfer tubes 24 have a
substantially U-form constituted by a lower pass 25 and an upper
pass 26, and are horizontally projected into an upper portion of
the inner space of the shell 1. The heat transfer tubes 24 are
situated in the intermediate fluid 9 of gaseous phase.
[0034] Thus, the intermediate fluid type vaporizer has such a
structure that the shell 1 of the intermediate fluid evaporator E1
includes therein both the heat source tubes 2 for evaporating the
intermediate fluid 9 of liquid phase with heat exchange between the
heat source fluid and the liquid intermediate fluid 9, and the heat
transfer tubes 24 of the LNG evaporator E2 for evaporating the LNG
with heat exchange between the LNG and the intermediate fluid 9 of
gaseous phase.
[0035] The NG heater E3 is provided separately from the
intermediate fluid evaporator E1 and the LNG evaporator E2, and it
comprises a shell 31, an inlet chamber 32, an outlet chamber 33,
and a large number of heat source tubes 34 for connecting both the
chambers 32, 33 to each other. The NG outgoing from the outlet
chamber 23 of the LNG evaporator E2 is introduced to the shell 31
of the NG heater E3 through a conduit 35. The heat source fluid
outgoing from the outlet chamber 23 of the NG heater E3 is
introduced to the heat source inlet chamber 3 of the intermediate
fluid evaporator E1. The NG heater E3 serves to heat the NG with
heat exchange between the NG and the heat source fluid.
[0036] A method of vaporizing the LNG by using the above-described
intermediate fluid type vaporizer will now be described with
reference to FIG. 1. A heat source fluid, such as warm water or an
aqueous solution of glycol, flows into the heat source outlet
chamber 4 after passing through the NG heater E3, the heat source
inlet chamber 3 of the intermediate fluid evaporator E1, the heat
source tubes 2 of the first tube bundle 11 (see FIG. 2), the return
chamber 5, and the heat source tubes 2 of the second tube bundle 12
(see FIG. 2). While passing through the heat source tubes 2, the
heat source fluid is subjected to heat exchange with the
intermediate fluid 9 of liquid phase in the intermediate fluid
evaporator E1, thereby evaporating the liquid intermediate fluid 9.
On the other hand, LNG to be vaporized is introduced to the heat
transfer tubes 24 through the inlet chamber 22. The evaporated
intermediate fluid 9 condenses with heat exchange between the LNG
in the heat transfer tubes 24 and the intermediate fluid 9 of
gaseous phase in the intermediate fluid evaporator E1. By receiving
heat generated upon condensation of the gaseous intermediate fluid
9, the LNG evaporates and becomes NG in the heat transfer tubes 24.
The produced NG is introduced to the shell 31 of the NG heater E3
from the outlet chamber 21 through the conduit 35, and is further
heated with heat exchange between the NG and the heat source fluid
flowing through the heat source tubes 34 in the NG heater E3.
Thereafter, the NG is supplied to consumers.
[0037] In the intermediate fluid type vaporizer of this embodiment,
since warm water, an aqueous solution of glycol or the like is
employed as the heat source fluid, a relatively large temperature
difference can be utilized for vaporization, whereby the required
flow rate of the heat source fluid can be reduced and more compact
design of the vaporization equipment can be realized. Also, the
heat source tubes 2 of the intermediate fluid evaporator E1 are
arranged so as to constitute two passes, and the number of the heat
source tubes 2 for each pass is reduced. In spite of the reduced
flow rate of the heat source fluid, therefore, a flow speed of the
heat source fluid in the heat source tubes 2 can be maintained at
an appropriate level, and the vaporizer can be designed with high
efficiency while maintaining a high film heat transfer coefficient.
Further, since the heat source tubes 2 are arranged so as to
constitute two passes, a sufficient heat transfer area can be
ensured, and hence an axial length of the vaporizer can be reduced.
Moreover, since the two passes of the heat source tubes 2 are
constituted by the combination of straight tubes and a return
chamber rather than using U-tubes, the two tube bundles 11, 12 can
be arranged closer to each other in a more compact structure, and
the diameter of the shell 1 can be reduced. As a result of the
combined effect of those features, it is possible to realize more
compact design and a cost reduction of the vaporizer comprising the
intermediate fluid evaporator E1 and the LNG evaporator E2 which
are constructed as an integral unit.
[0038] Also, since the shell 1 being in common to both the
intermediate fluid evaporator E1 and the LNG evaporator E2 has a
reduced diameter, the volume of the shell 1 can be reduced, and the
amount of the intermediate fluid to be maintained in the shell can
also be reduced. Therefore, the isolation distance required for in
accordance with the applicable regulations can be set to a smaller
value.
[0039] Furthermore, since the heat source tubes 2 of the
intermediate fluid evaporator E1 are constituted by the combination
of straight tubes and a return chamber, it is possible to more
easily carry out inspection and maintenance of the heat source
tubes 2, which require the chambers 3, 4 and 5 at the opposite ends
of the shell 1 to be removed when the inspection and maintenance
are carried out. Should the heat source tubes are damaged, they can
be replaced by new ones.
[0040] Moreover, since the NG heater E3 is constituted as an
independent heat exchanger separate from the intermediate fluid
evaporator E1 and the LNG evaporator E2, the NG heater E3 can be
freely designed from the viewpoint of chemical engineering without
being affected by the size of the shell 1 unlike the case where the
shell 1 is used in common to both the intermediate fluid evaporator
E1 and the NG heater E3, whereby the NG heater E3 can be
constructed in more compact size. In addition, a more free
arrangement and combination of the NG heater E3 can be realized
relative to the intermediate fluid evaporator E1 and the LNG
evaporator E2. For example, as shown in FIG. 4, the shell 1 of the
intermediate fluid evaporator E1 and the shell 31 of the NG heater
E3 may be arranged in parallel. Alternatively, as shown in FIG. 5,
the shell 31 of the NG heater E3 may be mounted on the shell 1 of
the intermediate fluid evaporator E1. This vertical mounting of the
shells can reduce an overall installation area of the
vaporizer.
[0041] Note that the present invention is not limited to the
illustrated embodiment, but may be implemented, by way of example,
as follows.
[0042] (1) The intermediate fluid type vaporizer may comprise only
the intermediate fluid evaporator E1 and the LNG evaporator E2. If
the temperature of the NG vaporized by the LNG evaporator E2 is not
lower than 0.degree. C., the vaporized NG can be directly supplied
to consumers without being heated by the NG heater E3.
[0043] (2) The heat source tubes 2 of the intermediate fluid
evaporator E1 can be constructed so as to provide three, four or
more passes. In these cases, a partition wall is provided between
adjacent chambers at the opposite ends of the shell 1 for
appropriate separation. Employing an even number of passes, such as
four or six passes, is more advantageous from the standpoint of
piping design because outlets and inlets of the heat source tubes 2
can be arranged at one end of the shell 1.
[0044] (3) The heat source fluid used in the present invention is
not limited to warm water or an aqueous solution of glycol, but may
be selected from other various heat source fluids.
[0045] (4) The intermediate fluid used in the present invention is
not limited to propane, but may be selected from other various
fluids.
[0046] (5) While the above description is made in connection with
the case of vaporizing LNG as liquefied gas, a target to be
vaporized is not limited to liquefied natural gas. The present
invention is also applicable to vaporization of, e.g., liquefied
ethylene, LO.sub.2 (liquefied oxygen), and LN.sub.2 (liquefied
nitrogen).
[0047] According to the intermediate fluid type vaporizer of the
present invention, as described above, heat source tubes of an
intermediate fluid evaporator are formed by straight tubes arranged
so as to constitute two or more passes. Therefore, when a heat
source fluid capable of providing a relatively large temperature
difference utilizable for vaporization at a smaller flow rate is
used and flows through the heat source tubes, a flow speed of the
heat source fluid in each heat source tube can be increased, and a
reduction of the boundary-film heat transfer coefficient can be
prevented. In addition, a sufficiently large heat transfer area can
be ensured between the heat source fluid and each heat source tube,
and tube bundles constituted by respective groups of the heat
source tubes can be arranged closer to each other. As a result, a
more efficient and compact vaporizer can be achieved.
[0048] Also, a gas heater is provided independently of both the
intermediate fluid evaporator and a liquefied gas evaporator.
Therefore, the gas heater can be installed in appropriate layout
and can be freely designed from the viewpoint of chemical
engineering depending on conditions required in constructing the
intermediate fluid type vaporizer, e.g., a restriction in
installation area of the vaporizer. Consequently, an installation
area of the intermediate fluid type vaporizer can be minimized.
[0049] Further, by employing the intermediate fluid type vaporizer
of the present invention and using the heat source fluid which can
provide a relatively large temperature difference utilizable for
vaporization, it is possible to efficiently vaporize liquefied
natural gas into natural gas and supply the natural gas to
consumers.
* * * * *