U.S. patent application number 14/690740 was filed with the patent office on 2015-08-13 for steam generator.
The applicant listed for this patent is TSINGHUA UNIVERSITY. Invention is credited to Shuyan HE, Huaiming JU, Xiaowei LUO, Xinxin WU, Zongxin WU, Zhengming ZHANG, Zuoyi ZHANG.
Application Number | 20150226419 14/690740 |
Document ID | / |
Family ID | 41122608 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150226419 |
Kind Code |
A1 |
HE; Shuyan ; et al. |
August 13, 2015 |
STEAM GENERATOR
Abstract
A steam generator includes a heat exchanger, a liquid header and
a steam header. The heat exchanger is assembled by several heat
exchanging subassemblies with the same structure. The heat
exchanging subassembly includes a spiral heat transmission pipe
bundle, a central cylinder and a sleeve. The spiral heat
transmission pipes with different radii are concentrically and
spirally arranged in an annular space between the central cylinder
and the sleeve, to form one or more concentric heat exchanging
pillar surfaces. One end of the liquid header is connected with a
main water feeding pipe, and the other end of the liquid header is
connected with the spiral heat transmission pipe bundle. One end of
the steam header is connected with a main steam pipe, and the other
end of the steam header is connected with the spiral heat
transmission pipe bundle.
Inventors: |
HE; Shuyan; (Beijing,
CN) ; JU; Huaiming; (Beijing, CN) ; WU;
Xinxin; (Beijing, CN) ; LUO; Xiaowei;
(Beijing, CN) ; ZHANG; Zhengming; (Beijing,
CN) ; WU; Zongxin; (Beijing, CN) ; ZHANG;
Zuoyi; (Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TSINGHUA UNIVERSITY |
Beijing |
|
CN |
|
|
Family ID: |
41122608 |
Appl. No.: |
14/690740 |
Filed: |
April 20, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13318729 |
Nov 3, 2011 |
9062918 |
|
|
PCT/CN2009/000666 |
Jun 18, 2009 |
|
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14690740 |
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Current U.S.
Class: |
122/1B ;
122/235.15; 122/235.29; 122/249; 122/406.4 |
Current CPC
Class: |
F22B 1/18 20130101; F22B
21/28 20130101; F22B 29/064 20130101; F28F 9/028 20130101; F22B
29/067 20130101; F22B 29/06 20130101; F22B 37/64 20130101; F22B
21/26 20130101; F28D 7/024 20130101; F22B 1/1823 20130101 |
International
Class: |
F22B 29/06 20060101
F22B029/06; F22B 37/64 20060101 F22B037/64; F22B 21/28 20060101
F22B021/28 |
Foreign Application Data
Date |
Code |
Application Number |
May 6, 2009 |
CN |
200910083490.5 |
Claims
1. A steam generator, comprising: a heat exchanger, assembled by
several heat exchanging subassemblies with the same structure, each
heat exchanging subassembly includes a spiral heat transmission
pipe bundle including a plurality of spiral heat transmission
pipes, a central cylinder and a sleeve, the spiral heat
transmission pipes having different radii are concentrically and
spirally arranged in an annular space between the central cylinder
and the sleeve, to form one or more concentric heat exchanging
pillar surfaces; a liquid header, one end of which is connected
with a main water feeding pipe, and the other end of which is
connected an end of each heat exchanging subassembly; and a steam
header, one end of which is connected with a main steam pipe, and
the other end of which is connected with an opposing end of each
heat exchanging subassembly; each spiral heat transmission pipe
including a radius of curvature configured to receive a sensing
probe for determining a volume and a surface area of each
transmission pipe such that the sensing probe can reach the
transmission pipes and pass through all the way.
2. The steam generator of claim 1, wherein along the direction of
axis of the central cylinder, the way of winding for the spiral
heat transmission pipes in the spiral heat transmission pipe bundle
are arranged to be one of clockwise, counterclockwise or a
combination of clockwise and counterclockwise.
3. The steam generator of claim 1, wherein a cross section of each
of the spiral heat transmission pipe bundle, the central cylinder
and the sleeve is in circular shape or rectangle shape with arc
corners.
4. The steam generator of claim 1, wherein the liquid header is
arranged upstream of the heat exchanger, the steam header is
arranged downstream of the heat exchanger, or, the steam header is
arranged upstream of the heat exchanger and the liquid header is
arranged downstream of the heat exchanger.
5. The steam generator according to claim 1, wherein inside the
part of the connection with the liquid header, each spiral heat
transmission pipe is installed with a fixed orifice plate and a
detachable orifice plate, the fixed orifice plate is used for
ensuring the stability of the flowing of two-phase fluid in the
spiral heat transmission pipe and distributing the resistance of
each spiral heat transmission pipe, and when one spiral heat
transmission pipe is out of work, the detachable orifice plate is
used for realizing the reallocation of flow in the spiral pipe by
detaching the detachable orifice plate of other spiral heat
transmission pipes on the spiral pillar surfaces on which the
spiral heat transmission pipe out of work is located.
Description
PRIORITY CLAIM
[0001] This application is a continuation of and claims priority to
U.S. patent application Ser. No. 13/318,729 filed on Nov. 3, 2011,
which claims priority to PCT Application No. PCT/CN2009/000666
filed on Jun. 18, 2009, which claims priority to Chinese Patent
Application No. 200910083490.5 filed on May 6, 2009, the entire
contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to the technical field of
steam power cycle, and particularly relates to a steam
generator.
BACKGROUND
[0003] On the basis of Rankine cycle, the water vapor power cycle
has been widely used in the fields of nuclear power, combined fuel
gas-steam cycle and coal-fired power station, etc. In these fields,
the generation of water vapor with high temperature and high heat
is the first step for the conversion from the thermal energy into
the power. At present, there are mainly two types of equipments for
the generation of water vapor, which are the natural cycle steam
generator and the once-through steam generator. In comparison with
the natural cycle steam generator, the once-through steam generator
can directly generate overheated steam and steam with super high
pressure and supercritical parameters, which has not only higher
generating efficiency, but also a compact structure.
[0004] According to its way of arrangement in the once-through type
steam generator, a hot water pipe can be classified into two types
which are the straight pipe and the spiral pipe. In comparison with
the arrangement of the spiral pipe, the structure of the
once-through steam generator of a straight pipe type is simpler,
but as the material of its heat exchanging pipe is different from
that of its cylinder, there is a difference between their linear
expansions, resulting in the concentration of stresses at the heat
transmission pipe and the pipe plate, and affecting the safety of
the operation of overall equipments. Although the total heat
exchanging area of the once-through steam generator of spiral pipe
type is relatively large, its structural feature can well solve the
problem of stress concentration phenomenon, and it is more flexible
in terms of space flexibility.
[0005] Because of the above advantages of the once-through steam
generator of spiral pipe type, it is widely used in the fields of
nuclear reactor electricity generation and power. The main designs
are classified into two types which are the integrated design of
large spiral pipe type and the separated modularization design.
[0006] The THTR-300 thorium high-temperature gas-cooled reactor in
Germany, the Saint Flensburg high-temperature gas-cooled reactor in
USA, the AGR type reactor in UK, and even the newest Sodium Cooled
Fast Reactor all utilize the once-through steam generator of large
spiral pipe type with multi-head winding and integration
arrangement. One of the advantages of such steam generator is its
compact structure. Furthermore, since the radius of curvature of
the spiral is large, the volume inspection and surface inspection
can be conducted. The main problems for such device include: 1)
since the design can not be verified by conducting external thermal
state test outside the reactor, the water flow side can not be
reallocated in the operation, which is prone to result in the
unevenness of steam temperature; 2) For the once-through steam
generator of large spiral pipe type with integration arrangement,
the spiral pipe in each layer needs independent tool pieces as the
diameter of curvature of the spiral pipe in each layer is
different, the processing expense thus is costly and the period is
relatively long; 3) In order to prevent from the flow-induced
vibration, more supporting plates are required, and the problem of
local overstress for the heat exchanging pipes and the supporting
plates is further highlighted.
[0007] The VG-400, ATY-50, .GAMMA.P-300 reactors in Russia and the
10 MW high-temperature gas-cooled test reactor in Tsinghua
University all utilize separated modularization once-through steam
generator. The main advantages for such type of steam generator are
that the module can be produced in batches, the production cost is
low, and each module can conduct external thermal state
verification test outside the reactor. The main problems for such
device include: 1) the structure is not compact enough; 2) the
small radius of curvature of the spiral pipe can not conduct the
volume and surface in-service inspection; 3) when a pipe blockage
takes place, not only the water flow side is blocked, the side of
high-temperature heat transfer material is blocked as well.
SUMMARY
[0008] The technical problem to be solved by the present invention
is to provide a steam generator, in order to overcome the
respective defects of integrated, large spiral pipe type design and
separated modularization design in the prior art, which may realize
in-service inspection for the volume and surface of the heat
transmission pipe to find the hidden safety hazard in time, and
carry out a thermal to state verification test before use to verify
the reliability of the design.
[0009] In order to achieve the above objectives, the present
invention provides a steam generator comprising: a heat exchanger,
assembled by several heat exchanging subassemblies with the same
structure, wherein the heat exchanging subassembly includes a
spiral heat transmission pipe bundle, a central cylinder and a
sleeve, wherein the spiral heat transmission pipes with different
radii are concentrically and spirally arranged in a annular space
between the central cylinder and the sleeve to form one or more
concentric heat exchanging pillar surfaces; a liquid header, one
end of which is connected with a main water feeding pipe, and the
other end of which is connected with the spiral heat transmission
pipe bundle; a steam header, one end of which is connected with a
main steam pipe, and the other end of which is connected with the
spiral heat transmission pipe bundle.
[0010] Wherein, the heat exchanging pillar surface is comprised of
one or more spiral heat transmission pipes.
[0011] Wherein, the radius of curvature of the spiral heat
transmission pipe satisfies that the volume and surface sensing
probe for piping materials can reach and pass through all the
way.
[0012] Wherein, along the direction of axis of the central
cylinder, the way of winding for the spiral heat transmission pipe
bundle on the adjacent heat exchanging surfaces includes: to be
arranged clockwise and anticlockwise alternatively, or to be
arranged fully clockwise, or to be arranged fully
anticlockwise.
[0013] Wherein, the cross section of each of the spiral heat
transmission pipe bundle, the central cylinder and the sleeve is in
circular shape or rectangle shape with arc corners.
[0014] Wherein, in the flowing direction of the heat transfer
medium, the liquid header is arranged at the upstream of the heat
exchanger and the steam header is arranged at the downstream of the
heat exchanger, or, the steam header is arranged at the upstream of
the heat exchanger, and the liquid header is arranged at the
downstream of the heat exchanger.
[0015] Wherein, the placement modes for the steam generator
include: the vertical type placement, the horizontal type
placement, or the placement at any angle.
[0016] Wherein, inside the part of the connection with the liquid
header, each spiral heat transmission pipe is installed with a
fixed orifice plate and a detachable orifice plate; the fixed
orifice plate is used for ensuring the stability of the flowing of
the two-phase fluid in the spiral heat transmission pipe and
distributing the resistance of each spiral heat transmission pipe;
In case one of the spiral heat transmission pipes is out of work,
the detachable orifice plate is used for realizing the reallocation
of flow in the spiral pipe by detaching the detachable orifice
plate of other spiral heat transmission pipes on the spiral pillar
surfaces on which the spiral heat transmission pipe out of work is
located.
[0017] In comparison with the prior art, the technical solution of
the present invention has the following advantages:
[0018] 1) The subassemblies can be produced in batches, which
reduces the cost of production;
[0019] 2) Thermal state verification test can be conducted on each
subassembly outside the reactor;
[0020] 3) Each subassembly is comprised of several spiral pillar
surfaces, each spiral pillar surface is further comprised of
multi-head spiral pipes, thereby overcoming the defect of incompact
structure of the separated arrangement, and it is not prone to
induce flow-induced vibration, and makes the supporting structure
simple and reliable because of the small radius of curvature of the
spiral pipes and stable structure;
[0021] 4) The minimal radius of curvature of the spiral pipes is
selected according to to the reachability of the in-service
inspection tools at present, the heat transmission pipes of each
subassembly are not provided with headers, but all connected to the
same liquid header and the same steam header, thereby enabling the
volume and surface in-service inspection. And when pipe blockage
takes place, only one pipe but not a module is to be blocked,
thereby maintaining the maximum availability is for the heat
transmission pipes;
[0022] 5) The design for the fixed orifice plate and the detachable
orifice plate can make the reallocation of flow after pipe blockage
simple and feasible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a longitudinal section view of a steam generator
in the horizontal high-temperature fluid passage of embodiment 1 of
the present invention;
[0024] FIG. 2 is a longitudinal section view of a steam generator
in the horizontal high-temperature fluid passage of embodiment 2 of
the present invention;
[0025] FIG. 3 is a longitudinal section view of a steam generator
in the vertical high-temperature fluid passage of embodiment 3 of
the present invention;
[0026] FIG. 4 is a longitudinal section view of a steam generator
in the vertical high-temperature fluid passage of embodiment 4 of
the present invention;
[0027] FIG. 5 is a schematic view of the internal structure of the
heat exchanging subassembly in the embodiments of the present
invention;
[0028] FIG. 6 is a schematic view of the structure of the orifice
plate at the inlet of the spiral pipe in the embodiments of the
present invention.
DETAILED DESCRIPTION
[0029] The present invention still maintains the features of
modularization, but each subassembly is comprised of several spiral
pillar surfaces and each spiral pillar surface is further comprised
of multi-head spiral pipes, thereby overcoming the defect of
incompactness of the separated structure. The minimal radius of
curvature of the spiral pipes is selected according to the
reachability of the in-service inspection tools at present, the
heat transmission pipes of each subassembly are directly connected
to the same liquid header and the same steam header, thereby
enabling volume and surface in-service inspection. Furthermore,
when pipe blockage takes place, only one pipe but not a module is
to be blocked, thereby maintaining the maximum availability for the
heat transmission pipes. The orifice plate is installed at the
water feeding inlet of each heat transmission pipe. The orifice
plate is classified into two types which are the fixed orifice
plate and the detachable orifice plate. The fixed orifice plate
meets the requirement for initial flow allocation and stability,
and the detachable orifice plate meets the requirement for flow
reallocation after pipe blockage. Inside one subassembly, the
spiral pipes on the same spiral pillar surface are all in the same
helium flowing passage, when one of the pipes is blocked due to
breakdown, the helium flow can not be adjusted, thus in order to
ensure the uniformity of temperature at the steam outlet, the flow
of fluids inside other pipes on the same spiral pillar surface has
to be increased. Just by removing the detachable orifice plates of
other pipes on such spiral pillar surface, a flow reallocation
after pipe blockage can be carried out, thereby meeting the
requirements for uniformity of temperature at the steam outlet. The
throttle resistance of undamaged subassemblies does not require to
be adjusted, so does the throttle resistance of undamaged spiral
pipes in each layer in the damaged subassembly. The exact value of
the orifice plate can be determined by thermal state verification
test of a single subassembly, and the distribution of
high-temperature side flow in each subassembly can be verified by
wind tunnel test of the scale model of the high-temperature
side.
[0030] The embodiments of the present invention will be further
described in details in combination with figures and embodiments
below. The following embodiments are used for describing the
present invention, but not limiting the scope thereof.
Embodiment 1
[0031] A longitudinal section view of a steam generator in the
horizontal high temperature fluid passage is shown as FIG. 1, in
which the steam generator 1 is arranged in the flowing direction of
the heat transfer medium x, comprised of a liquid header 11, a
steam header 12 and a heat exchanger 13. In the present embodiment,
the steam generator 1 is placed horizontally. The liquid header 11
and the steam header 12 are respectively arranged at the two sides
of the heat exchanger 13, the present embodiment uses an upstream
arrangement solution, i.e., the steam header 12 is arranged at the
upstream of the heat exchanger 13, and the liquid header 11 is
arranged at the downstream.
[0032] One end of the liquid header 11 is connected to a spiral
heat transmission pipe bundle 3 and the other end thereof is
connected to a main water feeding pipe 14. One end of the steam
header 12 is connected to the spiral heat transmission pipe bundle
3 and the other end thereof is connected to a main steam pipe
15.
[0033] The heat exchanger 13 is assembled by several heat
exchanging subassemblies 2 with the same structure. The internal
structure of the heat exchanging subassembly in the present
embodiment is shown as FIG. 5, in which the heat exchanging
subassembly 2 is mainly comprised of a spiral heat transmission
pipe bundle 3, a central cylinder 4 and a sleeve 5. The spiral heat
transmission pipes 3 with different radii are concentrically and
spirally arranged in an annular space between the central cylinder
4 and the sleeve 5 to form one or more concentric heat exchanging
pillar surfaces 6, and each of the heat exchanging pillar surfaces
6 is comprised of one or more spiral heat transmission pipes 3
[0034] The cross section of each of the central cylinder 4, the
sleeve 5 and the spiral heat transmission pipe 3 may be in circular
shape or approximate circular shape (such as rectangle shape with
arc corners).
[0035] The radius of curvature of each of the spiral heat
transmission pipes 3 should satisfy the requirement that the
sensing probe for volume and surface of the piping materials can
reach and pass through all the way.
[0036] The way of winding for the spiral heat transmission pipe 3
in the heat exchanging pillar surfaces 6 is as follows: when
looking along the direction of axis of the central cylinder 4, the
way of winding for the spiral heat transmission pipe 3 on the
adjacent heat exchanging pillar surfaces 6 is arranged clockwise
and anticlockwise alternatively, or may be arranged fully
clockwise, or arranged fully anticlockwise.
[0037] Inside the part of the connection with the liquid header 11,
each spiral heat transmission pipe 3 is installed with an orifice
plate; the structure of the orifice plate at the inlet of the
spiral pipe in the embodiment of the present invention is shown as
FIG. 6. The orifice plate is classified into two types which are
the fixed orifice plate 7 and the detachable orifice plate 8. When
one spiral heat transmission pipe 3 is out of work, the
reallocation of flow in the spiral pipe 3 is realized by detaching
the detachable orifice plate 8 of other spiral heat transmission
pipes 3 on the spiral pillar surfaces 6 on which the spiral heat
transmission pipe 3 out of work is located.
Embodiment 2
[0038] A longitudinal section view of a steam generator in the
horizontal high temperature fluid passage is shown as FIG. 2. The
steam generator of the present embodiment is similar to that of
embodiment 1, with the only distinction that the liquid header 11
and the steam header 12 in the present embodiment uses a downstream
arrangement solution, i.e., the steam header 12 is arranged at the
downstream of the heat exchanger 13, and the liquid header 11 is
arranged at the upstream.
Embodiment 3
[0039] A longitudinal section view of a steam generator in the
vertical high temperature fluid passage is shown as FIG. 3, in
which the steam generator 1 includes a heat exchanger 13, a liquid
header 11 and a steam header 12. In the present embodiment, the
steam generator 1 is placed vertically. The liquid header 11 and
the steam header 12 are respectively arranged at the two sides of
the heat exchanger 13. The present embodiment uses an upstream
arrangement solution, i.e., the steam header 12 is arranged at the
upstream of the heat exchanger 13, and the liquid header 11 is
arranged at the downstream.
[0040] The heat exchanger 13 is assembled by several heat
exchanging subassemblies 2 with the same structure. The internal
structure of the heat exchanging subassembly in the present
embodiment is shown as FIG. 5, in which the heat exchanging
subassembly 2 comprises a spiral heat transmission pipe bundle 3, a
central cylinder 4 and a sleeve 5; the spiral heat transmission
pipes 3 with different radii are concentrically and spirally
arranged in an annular space between the central cylinder 4 and the
sleeve 5, to form one or more concentric heat exchanging pillar
surfaces 6. The heat exchanging pillar surface 6 is comprised of
one or more spiral heat transmission pipes. The radius of curvature
of the spiral heat transmission pipe 3 satisfies that the sensing
probe for volume and surface of the piping materials can reach and
pass through all the way, and along the direction of the axis of
the central cylinder, the way of winding for the spiral heat
transmission pipe 3 on the adjacent heat exchanging surfaces
includes: to be arranged clockwise and anticlockwise alternatively,
or to be arranged fully clockwise, or to be arranged fully
anticlockwise.
[0041] The cross section of each of the spiral heat transmission
pipe bundle 3, the central cylinder 4 and the sleeve 5 is in
circular shape or rectangle shape with arc corners. One end of the
liquid header 11 is connected to the main water feeding pipe 14 and
the other end thereof is connected to the spiral heat transmission
pipe bundle 3. One end of the steam header 12 is connected to the
main steam pipe 15 and the other end thereof is connected to the
spiral heat transmission pipe bundle 3.
[0042] As shown in FIG. 6, inside the part of the connection with
the liquid header, each spiral heat transmission pipe is installed
with a fixed orifice plate 7 and a detachable orifice plate 8. The
fixed orifice plate 7 is used for ensuring the stability of the
flowing of two-phase fluid in the spiral heat transmission pipe and
distributing the resistance of each spiral heat transmission pipe;
and when one spiral heat transmission pipe is out of work, the
detachable orifice plate 8 is used for realizing the reallocation
of flow in the spiral pipe by detaching the detachable orifice
plate of other spiral heat transmission pipes on the spiral pillar
surfaces on which the spiral heat transmission pipe out of work is
located.
Embodiment 4
[0043] A longitudinal section view of a steam generator in the
vertical high temperature fluid passage is shown as FIG. 4, the
steam generator of the present embodiment is similar to that of
embodiment 3 with the only distinction that arrangement solution is
used for the liquid header 11 and the steam header 12 in the
present embodiment uses a downstream arrangement solution, i.e.,
the steam header 12 is arranged at the downstream of the heat
exchanger 13, and the liquid header 11 is arranged at the
upstream.
[0044] The properties of the heat exchanging subassembly 2, the
fixed orifice plate 7 and the detachable orifice plate 8 of the
present invention are such that thermal state test verification can
be conducted before use.
[0045] The above descriptions are just the preferred embodiments of
the present invention, and it needs to be stated that without
departing from the technical principle of the present invention, a
person skilled in the art may also make some improvements and
embellishments, which should also be regarded as falling into the
scope of protection of the present invention.
INDUSTRIAL APPLICABILITY
[0046] The steam generator of the present invention includes a heat
exchanger, a liquid header and a steam header. A single subassembly
of the present invention can be subject to thermal state
verification test outside the reactor; meanwhile the structure of
each subassembly is stable and can be produced in batches, thereby
reducing the cost of production. The steam generator of the present
invention can realize in-service inspection for the volume and
surface of the heat transmission pipe, so as to find the hidden
safety hazard in time, and a thermal state verification test can be
carried out before use. Thus, the present invention can be utilized
in the industry.
* * * * *