U.S. patent application number 10/183169 was filed with the patent office on 2004-01-01 for high power density sorption heat store.
Invention is credited to Fuesting, Bernd, Muenn, Peter, Stach, Helmut, Welke, Hartmut.
Application Number | 20040000164 10/183169 |
Document ID | / |
Family ID | 32299336 |
Filed Date | 2004-01-01 |
United States Patent
Application |
20040000164 |
Kind Code |
A1 |
Stach, Helmut ; et
al. |
January 1, 2004 |
HIGH POWER DENSITY SORPTION HEAT STORE
Abstract
The invention relates to a high power density sorption heat
store, preferably for storing low-temperature heat, and is
characterized in that a tube jacket 2 is provided with tube bottoms
3, 3', and with heat exchange tubes 4, which penetrate the sorption
layer 5 between the carrier floors 6, 6'; the mat layers 9, ' are
in each case located in between; the tube jacket 2 essentially is
enclosed by a working fluid tank 10 comprising the working fluid
lines 11, 11' including the valves 12, 12', which in turn are in
connection with the mat layers 9, 9'; and the dip tank 13, in the
bottom area, comprises the passage 16; and heat exchange tubes 4
are proportionally equipped with ribs 27, and are loosely guided
through openings 29 of the carrier floor 6' and through the mat
layer 9' but are fixedly connected with the tube bottoms 3, 3'; and
the ribs 27 are enclosed by a finely perforated network 28. The
associated method relates to the autothermal vaporization of the
working fluid, wherein in an unloading process in a first step, the
liquid level in the working fluid tank 10 by flowing goes over from
the stand-by condition a into the start condition b, and in a
second step, a vaporization of the remaining liquid contents of the
working fluid tank 10 takes place. 0253us
Inventors: |
Stach, Helmut; (Prieros,
DE) ; Muenn, Peter; (Berlin, DE) ; Fuesting,
Bernd; (Berlin, DE) ; Welke, Hartmut;
(Ahrensfelde, DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
32299336 |
Appl. No.: |
10/183169 |
Filed: |
June 28, 2002 |
Current U.S.
Class: |
62/480 ;
62/437 |
Current CPC
Class: |
Y02E 60/142 20130101;
F28D 20/003 20130101; Y02E 60/14 20130101 |
Class at
Publication: |
62/480 ;
62/437 |
International
Class: |
F25D 011/00; F25B
017/08 |
Claims
1. A high power density sorption heat store, characterized in that
a tube jacket (2) is provided with tube bottoms (3, 3'), and with
heat exchange tubes (4) which penetrate the sorption layer (5)
between the carrier floors (6, 6'); the tube bottom (3), in the
bottom area of the heat store, is provided with the lower dome (7),
the tube bottom (3') in the top area is provided with the upper
dome (7'), on which, accordingly, the connecting sleeves (8, 8')
for the heat exchange are located; between the tube bottoms (3, 3')
and the carrier floors (6, 6') the mat layers (9, 9') are in each
case incorporated; the tube jacket (2) is essentially enclosed by a
working fluid tank (10) comprising the working fluid lines (11,
11') including the valves (12, 12'), which in turn are in
connection with the mat layers (9, 9'); the dip tank (13), in the
bottom area, comprises the passage (16) and carries the coiled tube
(14) that is equipped with the lines (15, 15'); in the top area,
the suction port (17) is present which goes over into the
aftercondenser (18) and is connected with the vacuum pump (20) via
the suction valve (19); and the sorption heat store (1) as a whole
or at least essentially in the area of the tube jacket (2) is
surrounded by an insulation (21).
2. The store of claim 1, characterized in that the heat exchange
tubes (4) are equipped with ribs (27) and are loosely guided
through openings (29) of the carrier floor (6') and through the mat
layer (9'), but are fixedly connected with the tube bottoms (3,
3'); the ribs (27) are enclosed by a finely perforated network
(28), and the cap (30) serves as the terminal seal located in the
proximity of the tube bottom (3) or of the tube bottom (3').
3. The store of claims 1 and 2, characterized in that the ribs (27)
are in a spiral shape and form one or more vaporizer parts (31)
attached to the tube bottom (3').
4. The store of claims 1 through 3, characterized in that a heat
exchange tube (4) preferably forms a vaporizer part (31) arranged
centrally-axially to the tube jacket (2).
5. The store of claims 1 through 4, characterized in that one or
more condenser parts (32) arranged in parallel to the axis of the
tube jacket (2) and attached to the tube bottom (3) are present,
and the ribs (27) are preferably arranged in the longitudinal
direction of the heat exchange tubes (4).
6. The store of claims 1 through 5, characterized in that a
condenser (33) is provided, in which conducting means (24) are
located; and an additional cooling means (26) is present.
7. The store of claims 1 through 6, characterized in that the heat
exchange tubes (4), in the proximity of the tube bottoms (3, 3'),
are equipped with an additional heating means (22).
8. The store of claims 1 through 6, characterized in that the dip
tank (13) is realized in the shape of a cup (23).
9. The store of claims 1 through 8, characterized in that within a
mat layer (9) or (9'), an auxiliary heating means (25) is
arranged.
10. The modified store of claims 1 through 7, characterized in that
the tube jacket (2) is arranged horizontally; one or more vaporizer
parts (31) is/are arranged candle-like in a plane transverse to the
longitudinal axis of the sorption heat store (1), and is/are
arranged adjacent to said longitudinal axis, and is/are comprised
of two ducts of heat exchange tubes 4, and the tube bottoms 3, 3'
are coincidingly identical.
11. The modified store of claims 1 through 10, characterized in
that only one carrier floor (6) or (6') including one mat layer (9)
or (9') is present.
12. The store of claim 11, characterized in that the working fluid
line (11) comprises a passage (34).
13. The store of claims 1 through 12, characterized in that the mat
layer/s (9) and/or (9') consist/s of a fibrous, woolen or knitted
mat.
14. The store of claims 1 through 12, characterized in that the mat
layer/s (9) and/or (9') consist/s of a package of porous foams or
granulates.
15. The store of claims 13 and 14, characterized in that the mat
layer/s (9) and/or (9') contain/s metallic components in the form
of wires or wire spirals.
16. The store of claims 4 and 5, characterized in that the mat
layer/s (9) and/or (9') protrude/s into the vaporizer parts (31) or
the condenser parts (32) and is/are enclosed by same within the
network (28).
17. A method of realizing cyclical processes for heat storage
inside the sorption heat store (1), characterized in that the
vaporization of the working fluid in the mat layer (9) ensues in
the autothermal way.
18. The method of claim 17, characterized in that, in an unloading
process in a first step, the liquid level in the working fluid tank
(10) by flowing goes over from the stand-by condition (a) into the
start condition (b), and in a second step, a vaporization of the
remaining liquid contents of the working fluid tank (10) takes
place.
19. The method of claim 17 and 18, characterized in that, during
the loading process of the store, an operating condition (c) is
adjusted in the working fluid tank (10) having a liquid level that
is above the liquid level of the condensing diphase mixture.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a high power density sorption heat
store, in particular for the temporal-periodical storage of
available heat, and to a method of heat storage.
[0003] 2. Description of Related Art
[0004] Sorption heat stores are used to temporally and locally
store periodically recurring heat energies with the help of a
working fluid, in a targeted and user-friendly way allowing the
power to be unloaded again, in a sorption-active micro-porous solid
matter storage material. Preferred applications concern the
seasonal or short-term storage of heat in housing and building
technologies for heating and air-conditioning of rooms or to heat
service water. Modern systems of sorption storage consist, as a
rule, of a heat-insulated container that is periodically loaded
with heat power in a targeted manner, and is again unloaded upon
recall. For this purpose, the working fluid is periodically
transformed in a gaseous state by means of vaporizers, and is bound
to suitable porous sorbents during the storage unloading process.
During this, sorption heat is released, which can be supplied to
further liquid or gaseous heat exchangers via circuits for the
available heat. In the loading process of the stores, a removal of
the working fluid from sorbents is carried out through means of
desorption. This ensues by feeding heat from power supply networks
or, preferably, from other locally available sources of heat, such
as devices for obtaining solar power or geothermal heat, with the
working fluid being again liquefied in associated condensers. Less
expensive thermal or electric forms of power may thus be stored
during slack periods in power supply networks, with the advantage
of then having additional amounts of available heat to be drawn on
in periods of increased power demand.
[0005] According to "Sorptionsspeicher--Saisonale Wrmespeicherung
mit hohen Energiedichten" (Sorption stores--seasonal heat storage
with high power densities), a company publication of UFE SOLAR
GmbH, Alfred-Nobel-Strasse 1, D-16225 Eberswalde/Brandenburg,
written by W. Mittelbach and H. -M. Henning, the power densities
exceed those of a conventional water storage unit by four to five
times, depending on the depth and range of the storage state
created.
[0006] In more recent proposals concerning sorption stores, it is
asserted to increase the power storage densities and the thermal
efficiency initially by introducing verbal concepts such as
"compact store" or "high-performance store" and the technical
measures derived therefrom, in that, on the whole, in a space
delimited due to the geometric dimensions of the apparatus, the at
least three, originally spatially separated areas sorption area,
vaporizer and/or condensation area, and an area for stocking the
working fluid, normally water, are united in one common container.
Solutions like this (cf. DE 40 19 669, DE 198 11 302, and EP 0 897
094) are relatively simple to manufacture and can be installed in
secondary rooms of buildings, e.g., of houses, and may be operated
with a certain expenditure for the regulation and control alone of
valves, serving the purpose of heating, air-conditioning and
preparing service water.
[0007] As a rule, the vaporizer and condenser are arranged below
the sorbent chamber, and are periodically successively flowed
through in most cases by two circuits representing alternatingly
switched heat exchange circuits of fossil fuel-operated heating
means and solar or geothermal circuits. The sorption-active store
volume must be capable of being evacuated and hermetically sealed,
in order to make maximum use of the cyclically reversible loading
cycle existing between the loading and unloading process. Hence,
the task of any development of a sorption store is to maximize this
loading cycle that is determined pressure-dependent by two
separated isotherms involved in the adsorption and desorption
process.
[0008] In this process, however, basic problems arise in
conjunction with the transport processes for fluid and heat with
regard to the heating, cooling and working fluids both in the inner
container volume, as well as via the surfaces of the conduit
systems providing for said transport:
[0009] The sorbents exhibit a markedly restricted heat
conductivity, so that the desired positive heat balance is impeded
in a preferred direction of the container, but also in one of its
transverse directions. As a rule, the sorbents consist of
granulized or pelletized particles, which, in the form of grain
beds, are present between the heat and flow conducting equipment.
For increasing the storage density, high filling portions are
sought, whereby necessary installations imparting the heat restrict
the storage-active space.
[0010] The free paths for the transport of the working fluid are
reduced within the beds due to the desired higher filling
proportions with sorbents. Moreover, the sorbents have outer and
inner pore systems, which have to be filled with working fluid as
completely as possible, so as to achieve a high storage
density.
[0011] By combining vaporizer and condenser parts within one
receptacle and in a narrow space, "bridges" short-circuiting the
transport processes arise across the heat and flow conducting
equipment within the receptacle, which shorten the desired course
of the balance processes throughout the entire sorbent space and
contribute to a flow bypass formation reducing the efficiency.
[0012] In a configuration of the sorption store in a compactness
which is not optimally high, the proportion of the external heat
insulation has to be relatively large, so as to achieve that a
sufficient power density remains maintained over a longer period of
time. Internal insulations between the vaporizer and condenser,
however, would additionally reduce the storage density.
Accordingly, with an increase of the dimensional scale, the
proportion of the external insulation may be reduced in that a
temperature gradient is established from the inner and warmer to
the outer and cooler spaces.
[0013] The more recent approaches scarcely furnish indications as
to how to solve these problems, either.
[0014] It is, however, known that usual modern heat exchangers,
e.g. designed as tube bundle or jacketed heat exchangers, are able
to limit and even reduce these problems to a high degree with an
optimal formation and configuration of up to several meters in
diameter. Heat exchangers are available in standardized
constructions and series established, for example, by norms for
tubular bundle heat exchangers, such as the German Standards DIN 28
182: Rohrleitungen, Durchmesser der Bohrungen in Rohrboden,
Umlenksegmenten und Stutzplatten; DIN 28 185: Rohrbndel-Einbauten
or DIN 28 008: Abma.beta.e und Toleranzen. The correspondingly
highly sophisticated knowledge on their design and dimensions is
likewise contained in standard works, such as in the handbooks
"Verfahrenstechnische Berechnungsmethoden" Teil 1-Wrmeubertrager;
Teil 5-Chemische Reaktoren; Apparate, Ausrustung und ihre
Berechnung, published by Deutscher Verlag fur Grundstoffindustrie,
Leipzig, 1981.
[0015] Furthermore, it is known from DE 39 25 704 that using ribbed
tubes as inner tubes, a relatively long travel path and a large
transfer surface for the second heat transfer medium around the
inner tube, and hence a good heat transmission is achieved in that,
for example, a flexible hose structure forming a flow channel is
shrunk onto the ribs. Such modified ribbed tubes, however, do not
yet allow a suitable guidance of the flow of working medium which
must be in connection with the sorbent via openings. For this
reason, more recent arrangements as in DE 195 39 105 relate to
so-called sorption heat exchangers, in which the channels for the
working fluid flowing in vapor form and the inner heat-conducting
elements are largely matched to one another in one of the
transverse dimensions. So as to increase the dimensional scale, a
favorable guidance of the working fluid may also ensue in a
preferred longitudinal direction (the main axis of the apparatus),
which guidance, however, is not yet assured with the chosen known
arrangement of heat-conducting lamellae. In sorption heat stores,
the possibilities of increasing the dimensional scale are limited
by the fact that, process-contingently, the solid sorbent cannot be
moved like a fluid.
[0016] The concern of realizing the vaporization and condensation
processes in one common apparatus and in a compact configuration,
to date has only been introduced on a major economic scale in the
field of thermal material separation, such as distillation and
rectification, e.g. for separating hydrocarbon mixtures to obtain
fuel for internal combustion engines. In water vaporization and
condensation processes, e.g. for the purpose of water purification,
this process may then turn out to be uneconomic, due to the high
vaporization heats required, when a combined heat process between
various partial processes or apparatus parts is not given, e.g. by
means of heat pumps. The efficiency of vaporization and
condensation processes, such as e.g. in DE 196 46 458 and DE 196 47
378 concerning the field of water treatment and water purification,
may be increased in that vaporizer and condenser are neighboring
each other, that a stepped heat gradient exists between these two,
and that the condensation of the vapor ensues in a direct heat
contact by means of a guidance through the condensate which is
already present, at least proportionately. This heat pump effect in
a way simulated is advantageously achieved within contact
condensers and by slowing down the two-phase mixture flowing
through the condenser while condensing. In a variant of the
sorption heat store as per DE 198 11 302, a so-called tank-in-tank
arrangement, it is already indicated that the active storage volume
is enclosed by a condenser or by the condensate container. With
respect to a decreasingly graduated heat transfer from the inside
to the outside, this arrangement has advantages in the transverse
dimensions, in that in the interior of the store, a heated storage
volume forms having a temperature gradient in the peripheral
direction, a condensation zone arises having a low temperature, so
that the outer heat insulation of the container is to a certain
extent relieved in its heat-insulating functions, and
correspondingly may be designed lower. In a schematic
representation of the condensation device, however, here, as well,
statements as to their configuration are not made. No other
solutions became known either, in which the vaporization of the
working fluid takes place directly in the store and in the
immediate proximity of the sorbent chamber.
SUMMARY OF THE INVENTION
[0017] The invention relates to a high power density sorption heat
store, preferably for storing low-temperature heats, and is
characterized in that, in accordance with the state of the art,
simple instrumental extensions for the heat conduction and flow
guidance of the working fluid are incorporated in commercially
available and standardized heat exchangers of various types for
fluid and heat transformation in solid matters, which instrumental
extensions achieve an improvement of the thermal efficiency due to
a combined heat process in the sorption heat store 1 itself, a tube
jacket 2 being provided having tube bottoms 3, 3' and heat exchange
tubes 4 penetrating the sorption layer between the carrier floors
6, 6', with mat layers 9, 9' being in each case located in between,
the tube jacket 2 being essentially enclosed by a working fluid
tank 10 comprising working fluid lines 11, 11' including the valves
12, 12', which in turn are in communication with the mat layers 9,
9', and the dip tank 13 comprising the passage 16 in the bottom
area, as well as that heat exchange tubes 4 are proportionately
provided with ribs 27 and are loosely guided through openings 29 of
the carrier floor 6' and the mat layer 9', but are fixedly
connected with the tube bottoms 3, 3', and the ribs 27 are enclosed
by a finely perforated network 28. The associated method relates to
the autothermal vaporization of the working fluid, whereby in a
unloading process in a first step the liquid level in the working
fluid tank 10 goes over by flowing from the stand-by condition (a)
into the start condition (b), and in a second step, a vaporization
of the remaining liquid content of the working fluid tank 10 takes
place.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In the accompanying drawings shows:
[0019] FIG. 1 the sorption heat store in an upright perpendicular
tank-in-tank container form as a modified tube bundle heat
exchanger, including plain tubes for the heat exchange,
[0020] FIG. 2 a modification of the heat store according to FIG. 1,
however, including immersion tubes for the heat exchange, and an
additional head condenser,
[0021] FIG. 3 a modification according to FIG. 2, including an
external tank for the working fluid, with the two tank halves drawn
separately representing identical parts of the same tank,
[0022] FIG. 4 a configuration of a heat exchange tube including an
integrated vaporizer and condenser part, respectively,
[0023] FIG. 5 a modification according to FIG. 1, including a
perpendicular vaporizer/condenser part according to FIG. 4,
[0024] FIG. 6 a modification according to FIG. 1, including a
perpendicular condenser/vaporizer part according to FIG. 4,
[0025] FIG. 7 a modification of the heat store according to FIG. 1,
however, in a horizontal configuration, including deviating tubes
for the heat exchange and a vaporizer according to FIG. 4, and
including a plate condenser.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The invention is based on the problem of eliminating the
disadvantages of the solutions proposed in the prior art.
[0027] The problem was solved by means of a high power density
sorption heat store, in which standardized and commercially
available heat exchangers, preferable bundle tube heat exchangers
of the known embodiment and of metallic construction are used as
the base body for a sorption heat store. The outer shell is
surrounded by a tank serving for stocking the working fluid and for
vaporizing the working fluid. In a cost-efficient manner, it is
comprised of synthetic material, preferably of a mineral
fiber-reinforced thermoplastic material. The heat exchanger and the
tank can be commonly evacuated and can be hermetically sealed, and
are surrounded by a common heat insulation. Between the carrier
floors, heat exchange tubes are attached and penetrate the sorption
layer in accordance with the carrier floor division. A particularly
inventive idea consists in that the heat exchange tubes are only
loosely guided through the openings of likewise standardized
carrier floors for the sorbent, having division ratios of the
openings corresponding to those of the heat exchange tubes. The
permitted and standardized maximum tolerance spacings of the
corresponding tube and opening diameters between the tubes and the
flanged edges of the openings, constitute the circular passage
openings for the vaporized working fluid into and out of the
sorption layer. It is understood that the tolerance spacings, in
the millimeter or submillimeter range, are below the smallest
dimension of the sorbent particles present in the bed. The
transport of the liquid or already vaporized working fluid in each
of the transverse directions of the heat exchanger is provided for
by the temperature-resistant mat layers that are situated between
the carrier floors and the carrier layers. The mat layers
preferably consist of a non-woven fiber mat that is absorbent and
takes up the originally liquid working fluid and prevents drops
which could damage the sorbent from directly entering into the bed.
In this case, the flanged edges additionally prevent the layers of
the still liquid working fluid covering the carrier floors from
flowing into the sorption layer.
[0028] The inventive high power density sorption heat store has the
advantage of recurring to successful solutions for heat exchange
processes and the chemical-catalytic reaction technology, as far as
its design and configuration is concerned, and of allowing for an
accurate enlargement of the dimensional scale with respect to the
state of knowledge on fluid and heat exchange processes on solid
matter beds.
[0029] Surprisingly, it has turned out that the inventive sorption
heat store exhibits an improved guidance of the working fluid,
which is intended to vaporize during the unloading process in the
volume of the sorbent via an extended surface cross-section of the
device in the immediate proximity of an input of the heat
carrier.
[0030] Furthermore, it is advantageous that the condensation of the
vaporized working fluid takes place outside of the sorbent volume
via a direct heat exchange with its own condensate, and that the
condenser part simultaneously constitutes the tank-like reservoir
supply of the store with liquid working fluid.
[0031] The inventive high power density heat sorption store is
suited for the temporal-periodic storage of heat, preferably
inputting low-temperature heat from solar or terrestrial origin,
and outputting available heat to a heat exchange network. In
accordance with the technical state of development, commercially
available and standardized heat exchangers of various types may be
used, such as are usual in the field of the chemical process
engineering and chemical-catalytic reaction technology. With the
participation of actively reacting and absorbing solid matters,
simple instrumental extensions for the heat conduction and flow
guidance of the working fluid are incorporated for the purpose of
its capability of evaporating and condensing, which extensions
achieve an improvement of the thermal efficiency by a combined heat
process in a compact sorption heat store 1 itself, with known
techniques being used for enlarging the dimensional scale, and
larger widths of various size ratios, performance ranges and
application fields being covered.
[0032] The mat layers may also consist of a package of a bedded
material absorbing liquid, e.g. of foam particles or of porous
mineral granulates. They may also contain heat-conductive,
preferably metallic fibers. Likewise, they may consist of fibrous,
woolen or knitted mats proportionally containing more extended
metallic components, such as wires or spirals made thereof.
Finally, they may also consist of foam metals forming open-pored
cellular structures. The metallic components may also be
lyophilized, and may therewith be wetted by liquids. Within the mat
layer, auxiliary heating means may also be arranged, e.g. in the
form of additional heat exchangers or as electric filament
windings, which additionally support the vaporization of the
working fluid.
[0033] The unloading process of the store by adsorption
advantageously ensues in the autothermal way, since with the
opening of the feed valve for the working fluid in the area of one
tube bottom, sufficient heat amounts are immediately available in
the vaporizer part by liberation of adsorption heats due to the
abruptly arising temperature increase in the evacuated sorbent. The
initiation of the vaporization process hence starts independently
due to the presence of minor residual vapor pressures of the
working fluid at temperatures of the mat layers and carrier floors
which are still low. The liquid level in the tank falls from a
stand-by condition to a lower level, the start condition, which is
determined by the proportion of the liquid that has already settled
on the carrier floor and has penetrated into the mat layer, and
that cannot further diminish for the time being via a working fluid
line which is open on the top and is provided with an upper
opening. Only with an increasingly raising temperature in the heat
store, the working fluid in the tank, as well, starts to vaporize,
and hence enters then into the mat layer in the form of vapor via
the working fluid line that is opened on the top. Thus, the
sorption heat store has a stable operational behavior or even
certain "emergency start qualities" without an undesired
penetration of still liquid working fluid into the sorbent layer
taking place.
[0034] The carrier floor in the proximity of the second carrier
floor of the heat exchanger, which appropriately is configured
completely identical, may consist of a mat layer provided with the
same fiber mat, via which ensues the desorption during the loading
process of the sorption heat store. The associated working fluid
line is guided within a dip tank in the tank, is downwardly
directed via an exhaust valve and, on the other hand, is opened
towards the forming condensate. In its lower zone, the dip tank
features passage openings for the fluid diphase mixture that is
guided through the forming and banking liquid condensate. On the
exterior wall of the dip tank, a heat exchanger is located that is
preferably realized and wound as a tube coil. By feeding a coolant
through this heat exchanger, a partial condensation of the working
fluid vapor may first ensue on the inner wall of the dip tank, and
then a more complete condensation may follow on the exterior wall
including the tube coil.
[0035] Loading of the heat store is initiated by applying a vacuum
in the head area. The dip tank acts as a contact condenser.
Possible non-condensed components of the working fluid are
separated in an aftercondenser that is connected upstream of the
vacuum generator and is appropriately air-cooled. A modification of
the heat store is also proposed, in which the condensation takes
place effectively and in two stages via a head condenser, which is
in flow-side connection with the dip tank. In heat stores having
larger transverse dimensions, at least two working fluid lines
ending in individual dip cups might be useful for an efficient
condensation.
[0036] Since both in the loading and the unloading process, heat
for the condensation of the working fluid has to be fed into the
heat store in a process-contingent manner, additional heaters may
be mounted on the heat exchange tubes, here, as well, for example
in the form of heating coils or electric filament windings.
[0037] By introducing various arrangements for the heat exchange in
the vaporizer and condenser part through a heat pump effect, flow
convection and heat conduction, an intensive combined heat process
may in cases be achieved even in different parts and in locally
separated zones of the inventive sorption heat store, which can be
controlled and regulated via appropriate circuits.
[0038] A further inventive idea consists in using modified heat
exchange tubes for the vaporization and condensation processes,
which are mounted in a selected division arrangement of the tube
and carrier floors, in such a manner that also in a preferred
direction of the apparatus, the longitudinal direction of the heat
store, a flow-promoting guidance takes place with a distribution of
the working fluid in the longitudinal direction. This is then
particularly reasonable when a large length/diameter ratio of the
sorption heat store has to be adjusted, and the risk of an
incomplete longitudinal balancing of the working fluid flow in the
sorption layer has to be excluded. Purposefully, ribbed tubes are
used as the heat exchange tubes, which, as vaporizer tubes are
surrounded by a perforated network on their circumference, thus
forming an additional flow channel and featuring openings for the
working fluid passage into the sorption layer. Here again, these
openings are intended to have dimensions that are considerably
smaller than the sorbent grain sizes. When the ribs are oriented
transversely to the working fluid flow, e.g. in the form of a
spiral winding on the heat exchange tube, then the working fluid
may flow in the axial direction over larger travel paths within the
sorption layer, and may thus reach various vertical layers while
vaporizing at the same time. Correspondingly arranged condensate
tubes appropriately are provided with longitudinal ribs, on which
the condensate at least in part runs down and may be drawn off in a
lower mat layer.
[0039] Within the flow channels, as well, mat layers may be
present. It is in particular advantageous that the mat layers for
the vaporizer and condenser parts, due to the capillary forces
exerted on the working fluid, act in a certain independence of
gravitational force. Thus, horizontal or oblique arrangements of
the sorption heat store in the surrounding space become possible
for the purpose of being adapted to local conditions. In this way,
heat stores are created in appropriate sizes and storage capacities
available to a commercial or also industrial use, and which may be
accommodated in larger indoor rooms.
[0040] It has also been found that the elements configured as
vaporizer parts can also function as condenser parts, and vice
versa, and that they can replace each other. These modifications
are purposeful for sorption heat stores of smaller dimensions, such
as private household heat stores.
[0041] Of course, several inventive sorption heat stores may be
modularly interconnected. According to the state of the art, these
are at least two heat stores which are operated in the loading and
unloading condition in a cyclic-alternating manner.
[0042] The essence of the invention consists in a combination of
known elements that mutually complement each other and hence result
in the advantage of use, which resides in that a high power density
sorption heat store is made available.
[0043] The invention will be explained by means of realization
examples without any restricting effect.
REALIZATION EXAMPLES
Example 1
[0044] With reference to FIG. 1, the sorption heat store 1 consists
of a tube jacket 2, which is connected inside of the two tube
bottoms 3, 3' with heat exchange tubes 4. The heat exchange tubes 4
penetrate the sorption layer 5, which in turn is arranged within
the two carrier floors 6, 6' between the tube floors. Tube bottom 3
is equipped with the bottom dome 7, tube bottom 3' is equipped with
the upper dome 7', on which the connecting sleeves 8, 8' of the
heat carrier are located accordingly. Between the tube bottoms 3,
3' and the carrier floors 6, 6', the mat layers 9, 9' are in each
case incorporated. The tube jacket 2 is essentially enclosed by a
working fluid tank 10 comprising the working fluid lines 11, 11'
with the valves 12, 12', which in turn are in connection with the
mat layers 9, 9'. The dip tank 13 carries the coiled tube 14
including the lines 15, 15', and features the passage 16 in the
bottom zone. In the upper zone, the suction port 17 is situated,
which goes over into the aftercondenser 18 and which is connected
with the vacuum pump 20 via the suction valve 19. The sorption heat
store 1 is surrounded by insulation material. The aftercondenser is
air-cooled.
Example 2
[0045] With reference to FIG. 2, the heat exchange tubes 4 are
equipped with an additional heating means 22 in the proximity of
the tube bottoms 3, 3'. The dip tank 13 has the shape of a cup 23.
The sorption layer 5 is obturated with a sieve bottom 35. In a
condenser 33 arranged on the top of the heat store, conducting
means 24 are situated.
Example 3
[0046] With reference to FIG. 3, an auxiliary heating means 25 is
provided within the vaporizer 3. In the condenser 33, an additional
cooling means 26 is incorporated.
Example 4
[0047] FIG. 4 shows a particular realization of the guidance for
the working fluid, in the form of heat exchange tubes 4 provided
with ribs 27 mounted in a spiral-shape, which heat exchange tubes
are loosely guided through openings 29 of the carrier floor 6' and
the mat layer 9', but are firmly rolled into the tube bottoms 3,
3'. The ribs 27 are enclosed by a finely perforated network 28.
Purposefully, a cap 30 serves as the terminal seal. With reference
to FIG. 5, this form of a working fluid guidance is used in smaller
sorption heat stores as a vaporizer part 31 arranged
centrally-axially with respect to the tube jacket 2. The line 11
features a passage 34. In the FIGS. 5 through 7, the insulation 21
is not represented.
Example 5
[0048] FIG. 6 shows a realization analogous to that of FIG. 5, with
the central heat exchange tube 4 being a condenser part 32 similar
to that of FIG. 4 and being provided with longitudinally directed
ribs 27.
Example 6
[0049] With reference to FIG. 7, the vaporizer part 31 including
the mat layer 9' is arranged candle-like in a plane transverse to
the longitudinal axis of the sorption heat store, and is arranged
adjacent to said longitudinal axis, and is comprised of two ducts
of heat exchange tubes 4. The tube bottoms 3, 3' are coincidingly
identical. The condenser part 33 is a plate condenser. The tube
jacket 2 and the tank 10 are arranged asymmetrical to each
other.
[0050] In the stand-by condition a of the sorption heat store, the
liquid working fluid is on a level situated above the inflow
opening of line 11. During unloading, after opening valve 12, the
liquid level of the liquid working fluid falls to the start
condition b. Due to the subsequent complete vaporization of the
working fluid, the store is unloaded.
[0051] In loading the store, the valves 12' and 19 are first
opened, and a connection to the vacuum pump 20 is established.
After closing of valve 19, an operation condition c arises during
the condensation of the working fluid, which is terminated with the
stand-by condition a.
[0052] List of Reference Numerals
[0053] 1 Sorption heat store
[0054] 2 Tube jacket
[0055] 3 Tube bottom
[0056] 3' Tube bottom
[0057] 4 Heat exchange tube
[0058] 5 Sorption layer
[0059] 6 Carrier floor
[0060] 6' Carrier floor
[0061] 7 Bottom dome
[0062] 7' Upper dome
[0063] 8 Connecting sleeve
[0064] 8' Connecting sleeve
[0065] 9 Mat layer
[0066] 9' Mat layer
[0067] 10 Working fluid tank
[0068] 11 Working fluid line
[0069] 11' Working fluid line
[0070] 12 Valve
[0071] 12' Valve
[0072] 13 Dip tank
[0073] 14 Coiled tube
[0074] 15 Feed line
[0075] 15' Feed line
[0076] 16 Passage
[0077] 17 Suction port
[0078] 18 Aftercondenser
[0079] 19 Suction valve
[0080] 20 Vacuum pump
[0081] 21 Insulation material
[0082] 22 Additional heating means
[0083] 23 Cup
[0084] 24 Conducting means
[0085] 25 Auxiliary heating unit
[0086] 26 Supplementary cooling means
[0087] 27 Rib
[0088] 28 Network
[0089] 29 Opening
[0090] 30 Closing cap
[0091] 31 Vaporizer part
[0092] 32 Condenser part
[0093] 33 Condenser
[0094] 34 Passage
[0095] 35 Sieve bottom
[0096] a Stand-by condition
[0097] b Start condition
[0098] c Operating condition
* * * * *