U.S. patent application number 11/996330 was filed with the patent office on 2011-07-14 for adsorption apparatus comprising a heat recovery system.
This patent application is currently assigned to SORTECH AG. Invention is credited to Soren Paulussen.
Application Number | 20110167842 11/996330 |
Document ID | / |
Family ID | 37776822 |
Filed Date | 2011-07-14 |
United States Patent
Application |
20110167842 |
Kind Code |
A1 |
Paulussen; Soren |
July 14, 2011 |
ADSORPTION APPARATUS COMPRISING A HEAT RECOVERY SYSTEM
Abstract
The invention relates to an adsorption machine, comprising at
least a first and a second adsorber unit which are each connected
to a forward motion (VL) and a return motion (RL), in order to
supply heat from a heat transfer medium of the adsorber unit
conducted through the forward motion (VL) to the adsorber unit or
to remove said heat from the adsorber unit to the heat transfer
medium; each adsorber unit works alternately in a desorption phase
as a desorber, wherein heat is removed from the heat transfer
medium to the desorber and in an adsorption phase as an adsorber,
wherein heat is removed from the adsorber to the heat transfer
medium; the adsorption machine comprises further at least two heat
transfer medium circuits, namely a heating circuit with a heat
source for heating up of the heat transfer medium, and a cooling
circuit with a heat sink for cooling of the heat transfer medium.
The invention is characterized in that a control unit is provided
which switches the forward motions (VL) and the return motions (RL)
individually alternately to the heating circuit and the cooling
circuit in such a way that the return motion with the highest
temperature always feeds its heat transfer medium to the heating
circuit.
Inventors: |
Paulussen; Soren; (Berlin,
DE) |
Assignee: |
SORTECH AG
Halle
DE
|
Family ID: |
37776822 |
Appl. No.: |
11/996330 |
Filed: |
December 5, 2006 |
PCT Filed: |
December 5, 2006 |
PCT NO: |
PCT/EP2006/011666 |
371 Date: |
December 16, 2008 |
Current U.S.
Class: |
62/79 ;
62/160 |
Current CPC
Class: |
Y02A 30/278 20180101;
Y02B 30/00 20130101; F28D 15/00 20130101; F25B 17/00 20130101; F25B
17/086 20130101; Y02A 30/27 20180101; Y02B 30/64 20130101; F25B
49/046 20130101 |
Class at
Publication: |
62/79 ;
62/160 |
International
Class: |
F25B 29/00 20060101
F25B029/00; F25B 17/00 20060101 F25B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 2005 |
DE |
10 2005 058 630.9 |
Mar 11, 2006 |
DE |
10 2006 011 409.4 |
Claims
1. Adsorptive machine, comprising at least a first and a second
adsorber unit which are each connected to a forward motion (VL) and
a return motion (RL), in order to supply heat from a heat transfer
medium of the adsorber unit (1) conducted through the forward
motion (VL) to the adsorber unit or to remove said heat from the
adsorber unit to the heat transfer medium; each adsorber unit works
alternately in a desorption phase as a desorber, wherein heat is
removed from the heat transfer medium to the desorber and in an
adsorption phase as an adsorber, wherein heat is removed from the
adsorber to the heat transfer medium; the adsorption machine
comprises further at least two heat transfer medium circuits,
namely a heating circuit with a heat source for heating up of the
heat transfer medium, and a cooling circuit with a heat sink for
cooling of the heat transfer medium, wherein a control unit is
provided which switches the forward motions (VL) and the return
motions (RL) individually alternately to the heating circuit and
the cooling circuit in such a way that the return motion with the
highest temperature always feeds its heat transfer medium to the
heating circuit; characterized in that the control unit is designed
in such a way that in the transition of the first adsorber unit
from the desorption phase to the adsorption phase and in the
transition of the second adsorber unit from the adsorption phase to
the desorption phase or vice versa first it connects the forward
motion (VL) of the adsorber unit which is connected as the new
desorber to the heating circuit so that the new desorber is fed
from the heating circuit and thus heated up, and the return motion
(RL) of this new desorber continues to be connected to the cooling
circuit until the temperature level of the heat transfer medium in
the return motion (RL) is increased by a preset extent, or is
warmer than the return motion (RL) of the other adsorber unit, and
the return motion (VL) of the new adsorber is connected to the
cooling circuit so that this new adsorber is cooled and the still
warm return motion (RL) of the new adsorber continues to remain
connected to the heating circuit until the temperature of the heat
transfer medium in the return motion (RL) has decreased by a
predetermined extent, or up to or below the temperature of the
return motion (RL) of the other adsorber unit.
2. The adsorption machine in accordance with claim 1 characterized
in that the control unit is designed in such a way that it always
switches the return motion (RL) with the lowest temperature in such
a way that it feeds its heat transfer medium to the cooling
circuit.
3. The adsorption machine according to claim 1, characterized in
that a temperature difference .DELTA.T.sub.X between the heating
circuit and the cooling circuit amounts to at least 10.degree. C.
or at least 20.degree. C. or at least 25.degree. C.
4. The adsorption machine according to claim 1, characterized in
that the adsorption machine comprises three heat transfer medium
circuits.
5. The adsorption machine according to claim 4, characterized in
that the third heat transfer medium circuit is a low temperature
circuit and exhibits a temperature difference .DELTA.T.sub.Y to the
heating circuit, wherein the temperature difference .DELTA.T.sub.Y
is greater than the temperature difference .DELTA.T.sub.X.
6. The adsorption machine according to claim 1, characterized in
that the heat transfer medium with the lowest temperature is
assigned to the low temperature circuit.
7. The adsorption machine according to claim 1, characterized in
that the adsorption machine comprises at least three adsorber
units.
8. The adsorption machine according to claim 1, characterized in
that water, water vapor or oil is used as the heat transfer
medium.
9. The adsorption machine according to claim 1, characterized in
that each adsorber unit comprises zeolite as an adsorbing
agent.
10. The adsorption machine according to claim 1, characterized in
that the adsorption machine is a refrigerating machine.
11. A method for heat recovery in an adsorption machine comprising
at least a first and a second adsorber unit which are each
connected to a forward motion (VL) and a return motion (RL), in
order to supply heat from a heat transfer medium of the adsorber
unit conducted through the forward motion (VL) to the adsorber unit
or to remove said heat from the adsorber unit to the heat transfer
medium and further comprising at least two heat transfer medium
circuits, namely a heating circuit with a heat source (3) for
heating up of the heat transfer medium, and a cooling circuit with
a heat sink (4) for cooling of the heat transfer medium, wherein
each adsorber unit works alternately in a desorption phase as a
desorber, wherein heat is removed from the heat transfer medium to
the desorber and in an adsorption phase as an adsorber, wherein
heat is removed from the adsorber to the heat transfer medium; and
the forward motions (VL) and the return motions (RL) are switched
individually alternately to the heating circuit and the cooling
circuit in such a way that the return motion with the highest
temperature always feeds its heat transfer medium to the heating
circuit; characterized in that in the transition of the first
adsorber unit from the desorption phase to the adsorption phase and
in the transition of the second adsorber unit from the adsorption
phase to the desorption phase or vice versa first the forward
motion (VL) of the adsorber unit which is connected as the new
desorber is connected to the heating circuit so that the new
desorber is fed from the heating circuit and thus heated up, and
the return motion (RL) of this new desorber continues to be
connected to the cooling circuit until the temperature level of the
heat transfer medium in the return motion (RL) is increased by a
preset extent, or is warmer than the return motion (RL) of the
other adsorber unit, and the return motion (VL) of the new adsorber
is connected to the cooling circuit so that this new adsorber is
cooled and the still warm return motion (RL) of the new adsorber
continues to remain connected to the heating circuit until the
temperature of the heat transfer medium in the return motion (RL)
has decreased by a predetermined extent, or up to or below the
temperature of the return motion (RL) of the other adsorber
unit.
12. The method in accordance with claim 11, characterized in that
the return motion (RL) with the lowest temperature is always
switched in such a way that it feeds its heat transfer medium to
the cooling circuit.
13. The method in accordance with claim 12, characterized in that
the switching of the forward motions (VL) and of the return motions
(RL) takes place by means of a control unit which compares the
temperatures of the return motions (RL) with each other.
14. The method in accordance with claim 11, characterized in that
the switching of the forward motions (VL) and of the return motions
(RL) takes place by means of a control unit which compares the
temperatures of the return motions (RL) with each other.
15. The adsorption machine according to claim 2, characterized in
that a temperature difference .DELTA.T.sub.X between the heating
circuit and the cooling circuit amounts to at least 10.degree. C.
or at least 20.degree. C. or at least 25.degree. C.
16. The adsorption machine according to claim 2, characterized in
that the adsorption machine comprises three heat transfer medium
circuits.
17. The adsorption machine according to claim 3, characterized in
that the adsorption machine comprises three heat transfer medium
circuits.
18. The adsorption machine according to claim 2, characterized in
that the heat transfer medium with the lowest temperature is
assigned to the low temperature circuit.
19. The adsorption machine according to claim 3, characterized in
that the heat transfer medium with the lowest temperature is
assigned to the low temperature circuit.
20. The adsorption machine according to claim 4, characterized in
that the heat transfer medium with the lowest temperature is
assigned to the low temperature circuit.
Description
[0001] The subject matter of the present invention is an adsorption
machine, in particular an adsorption cooling machine for
refrigeration.
[0002] Thermally driven adsorption machines on the basis of solid
adsorption for heating and cooling purposes have been known for
some time. In the process conventional working substance
pairs--sorption material and adsorbate--such as for example zeolite
and water are used. Adsorption machines with such a working
substance pair are for example described with DE 198 34 696, DE 199
61 629, DE 100 38 636, DE 101 59 652 or DE 102 17 443.
[0003] Various technical demands are made on adsorption machines.
Particularly important are the demands for a high thermal ratio, a
high power density and an easy adjustability of the heat loss. The
thermal ratio of the effective heat to the driving heat--here and
in the following named Coefficient of Performance (COP)--depends
essentially on the shares of the sorptive and of the sensitive heat
transformation during an operating cycle. By sorptive
transformation one understands the release of the sorption heat
arising in the case of the adsorption of the working gas or the
absorption of the sorption heat required for desorption, whereas
the sensitive heat transformation describes the energy turnover
which occurs in the case of the heating up or cooling down of the
entire system.
[0004] In order to achieve particularly high thermal ratios more
and more sophisticated systems were developed, wherein in
particular through the arrangement of a multitude of adsorber
units, which are permeated successively by the heat transfer medium
and switched in a multitude of cycles, the highest possible heat
recovery is strived for. By heat recovery one understands any
recovery of heat--sorptive as well as sensitive--from the
adsorption phase, wherein the recovered heat can be used for the
desorption phase, in order hence to reduce the energy expenditure
of external heat sources for the desorption.
[0005] Adsorption machines with two adsorber units are
conventionally used for refrigeration. In these refrigerating
machines the adsorber units work alternately as adsorbers or
desorbers. The conventional control systems in the process work
between the adsorption phases with heat recovery phases which
partially conduct the heat energy of the adsorber unit that is
still hot to the adsorber unit that is still cold. Through these
heat recovery phases the energy present in the system is reused to
a certain extent, so that less energy must be supplied from the
outside. The efficiency of this heat recovery is thus critical for
the efficiency of the entire adsorption machine.
[0006] Conventional control system concepts conduct the heat
transfer medium during the heat recovery phase in parallel or
serial fashion through both adsorbers. For this purpose additional
components are required, for example reversing valves or pumps in
the heat transfer medium circuit system. Moreover this heat
transfer medium circuit is operated uncoupled from the other
circuits. This leads to the pumps mostly connected externally to
the adsorption machine not being able to send any volumetric flow
through the system during the time of the heat recovery and must
either be switched off or conducted past the system in a bypass.
The disadvantages of these systems are the considerable technical
expenditure, the susceptibility to failure and the high
manufacturing and maintenance costs.
[0007] The invention is based on the object of specifying an
adsorption machine and a method for heat recovery in an adsorption
machine which are improved with regard to the named disadvantages.
In particular the number of components should be reduced in
comparison with the known adsorption machines without worsening the
heat recovery, but rather possibly improving said heat recovery. In
particular the heat recovery should be able to be performed without
interruption of externally applied volumetric flows.
[0008] The object according to the invention is solved by an
adsorption machine with the features of Claim 1 and a method with
the features of Claim 12. The dependent claims describe
advantageous and particularly expedient embodiments of the
invention.
[0009] The adsorption machine according to the invention comprises
in other words at least a first and a second adsorber unit, a heat
transfer medium and at least two heat transfer medium circuits with
a temperature difference .DELTA.T.sub.X, of which one heat transfer
medium circuit is a heating circuit and the other heat transfer
medium circuit is a cooling circuit. Each adsorber unit works in a
first desorption phase as a desorber and works in a second
adsorption phase as an adsorber, wherein the heat transfer medium
exhibits a lower temperature in a return motion from a desorber
than in a forward motion to the desorber, and the heat transfer
medium exhibits a higher temperature in a return motion from an
adsorber than in a forward motion to the adsorber.
[0010] Consequently the heat transfer medium is cooled from a
forward motion in an adsorber unit working as a desorber, because
heat is transferred from the heat transfer medium to the adsorber
unit, and the heat transfer medium is heated up from a forward
motion in an adsorber unit working as an adsorber, because heat is
transferred from the heat transfer medium to the adsorber unit.
[0011] The heating circuit basically serves the purpose of
transferring heat from a heat source which is connected to the
heating circuit to the heat transfer medium so that said heat
transfer medium can heat up the desorber. The cooling circuit
basically serves the purpose of removing heat from the heat
transfer medium by means of a heat sink so that said heat transfer
medium can cool the adsorber.
[0012] The heating circuit can also be described as a high
temperature circle (HT circle) and the cooling circuit can be
described as a mean temperature circuit (MT circle). Accordingly by
HT source the heat source of the heating circuit is meant and by MT
sink the heat sink of the cooling circuit is meant, see FIG. 1.
[0013] The temperature difference between the high temperature
circuit and the mean temperature circuit is presently termed as
.DELTA.T.sub.X, wherein the temperature T.sub.H corresponds to the
upper limit of the temperature difference .DELTA.T.sub.X of the two
heat transfer medium circuits. The temperature T.sub.H is that
temperature to which the heat transfer medium should be set in the
high temperature circuit.
[0014] The temperature T.sub.M corresponds to the lower limit of
the temperature difference .DELTA.T.sub.X of the two heat transfer
medium circuits and that temperature to which the heat transfer
medium should be set in the mean temperature circuit.
[0015] Through the embodiment according to the invention an
adsorption machine can be created whose heat recovery is at least
as great as in the case of conventional adsorption machines and
which in the process manages without the integration of additional
components in the machine.
[0016] In particular the heat recovery of the adsorption machine
according to the invention can take place as a subprocess
integrated in the total process, wherein no volumetric flow
interruption occurs. The heat recovery can take place solely with
valves and in particular pumps, which are required for the sorption
phases anyway.
[0017] In particular in an adsorption machine in accordance with
the present invention provision is made that the temperature
difference .DELTA.T.sub.X is at least 10.degree. C. in particular
at least 20.degree. C. and especially preferably at least
25.degree. C. In the process in particular provision can be made
that the heat transfer medium in the high temperature circuit
exhibits a temperature T.sub.H of at least 70.degree. C. and a
maximum of 90.degree. C., and in particular from 75 to 85.degree.
C. In principle the adsorption machine according to the invention
or the method according to the invention is however suitable for
any temperature differences and temperature level.
[0018] In an alternative embodiment of the invention an adsorption
machine according to the invention can exhibit three heat transfer
medium circuits, wherein the high temperature circuit exhibits a
temperature difference .DELTA.T.sub.X to a second mean temperature
circuit and exhibits a temperature .DELTA.T.sub.Y to a third lower
temperature circuit, and wherein the temperature difference
.DELTA.T.sub.Y is greater than the temperature difference
.DELTA.T.sub.X.
[0019] With an adsorption machine according to the invention
advantageously each adsorber unit is not firmly connected to a heat
transfer medium circuit or assigned to it as usual, but rather is
assigned to a heat transfer medium circuit dependent on its
temperature in the return motion. This is in particular achieved as
a result of the valves not both being positioned in the same
direction in the forward and return motion of a component in a
control phase, but rather having the position made dependent on the
adjacent temperature level. In an adsorption machine according to
the invention the valves can be positioned in the forward motion of
both adsorber units at the beginning of the heat recovery phase in
such a way that the "new" desorber receives the heat transfer
medium from the high temperature circuit and consequently is heated
up. The return motion of this "new" desorber, which is still cold,
however continues to be conducted to the mean temperature circuit
until the temperature level increases significantly, in particular
by a preset extent or to a temperature equal to or above the return
motion of the "old" desorber, which is the "new" adsorber. Similar
to this the forward motion of the "new" adsorber is connected to
the mean temperature circuit, so that this "new" adsorber is
cooled. The return motion of the "new" adsorber, which is still
hot, however continues to be connected to the high temperature
circuit until the temperature level decreases significantly, in
particular by a preset extent or to a temperature equal to or below
the return motion of the "old" adsorber, which is the "new"
desorber.
[0020] FIG. 1 shows a hydraulic diagram of an exemplifying
embodiment of an adsorption machine according to the invention.
[0021] As one recognized in FIG. 1, the valves of the forward
motion group ( . . . _VL_. . . ) are differently connected during
the heat recovery than those of the return motion group ( . . .
_RL_. . . ). One advantage of this adsorption machine consists in
the fact that a heat recovery can take place without interruption
of the external volumetric flows.
[0022] With this during the heat recovery, the heat transfer medium
is conducted to the high temperature circuit at all times with the
highest available temperature in the return motion of the system.
As a result of this, on the one hand the energy which must be
provided from the outside to the system is minimized and on the
other hand through the embodiment of the adsorption machine it is
also guaranteed that at all times the heat transfer medium will be
conducted to the cooling circuit with the lowest temperature, so
that the least possible energy must be recooled. In particular, the
energy requirements are reduced when in accordance with an
embodiment of the invention pumps, as they are described in the
introductory part of the description with regard to the known
control concepts, are conserved.
[0023] In particular an adsorption machine according to the
invention comprises two adsorber units. These adsorption machines
can in particular produce cold in a two-stage, cyclical process. In
order to generate a continuous cold flow at least two adsorber
units are counter connected, so that one adsorber unit is being
dried while the other one produces cold. Fundamentally this process
runs all the more effectively the more the sorption material has
been dried previously--which in turn best succeeds with higher
driving temperatures.
[0024] Accordingly an adsorption refrigerating machine is also the
subject matter of the present invention. This adsorption
refrigerating machine comprises at least two adsorber units, one
heat transfer medium, at least two heat transfer medium circuits
with a temperature difference .DELTA.T.sub.X and one control unit,
wherein each adsorber unit works in a first desorption phase as a
desorber and in a second adsorption phase works as an adsorber, and
wherein the heat transfer medium in a return motion of the desorber
exhibits a lower temperature than in the forward motion to the
desorber and wherein the heat transfer medium in a return motion of
the adsorber exhibits a higher temperature than in a forward motion
to the adsorber, and wherein the heat transfer medium with the
highest temperature in the return motion of the first or any
further adsorber unit is connected to the high temperature
circuit.
[0025] Along with the adsorption machine itself a method for heat
recovery in an adsorption machine in accordance with Claim 12 is
also the subject matter of the present invention. In especially
preferred manner in the process the temperatures of the return
motions are compared with each other and the return motion with the
highest temperature is assigned to the high temperature
circuit.
[0026] The operating cycle of an adsorption machine according to
the invention can flow as follows. First minerals with a large
inner surface, in particular zeolite or silica gels, are dried by
heat supply during a desorption phase. When the material has been
sufficiently dried the heat supply is stopped and a valve to a
water container is opened. Due to the enormous inner surface and
the special crystal structure there is a very great suction of
water vapor or the evaporating of water in the second container. As
is the case with any evaporation process there is now a great
temperature decline in the water depending on the operating state
up to the formation of ice.
[0027] In order to produce a continuous cold flow two such systems
are counter connected so that one adsorber unit is drying while the
other one is producing cold. Alternately the present adsorption
machine can comprise three adsorber units or at least three
adsorber units. In particular provision is made in the process that
one adsorption machine comprises a maximum of five adsorber units.
In principle however the output of the adsorber machine can be
continuously expanded by the simple addition of further adsorber
units.
[0028] With an adsorption machine in accordance with the present
invention in particular by a reduction of the necessary pumps the
current consumption and also the generation of noise can be
significantly reduced. At the same time the electrical efficiency
is improved. For example the adsorption machine can exhibit pumps
exclusively in the external heat transfer medium circuits, that is
between the heat sources and/or heat sinks and the adsorber units,
for example a single pump per eternal circuit, as shown in FIG. 1.
The adsorber units themselves can be designed free of pumps.
[0029] Waste heat or excess heat from existing systems can be used
as a heat source, for example engine-based cogeneration systems,
solar plants or process waste heat.
* * * * *