Technical field of the invention
[0001] The present invention relates to the field of energy handling. More particularly,
the present invention relates to systems and methods for handling energy, such as
for example storing, converting or transmitting energy, whereby the energy handling
is performed with high efficiency and low losses.
Background of the invention
[0002] The consumption of energy as well as the demand for producing energy in an environmental
friendly manner has been increasing over the last decades and - amongst others due
to global warming - it is expected to further increase over the following years. It
therefore is of utmost importance that energy handling is performed in an efficient
manner.
[0003] Although a number of energy handling, storing and conversion systems have been explored
over the last tens of years, there is still a quest for efficient energy handling
systems.
Summary of the invention
[0004] It is an object of the present invention to provide a good system and method for
handling energy, e.g. storing, transmitting or converting energy. It is an advantage
of embodiments of the present invention that efficient systems and methods for handling
energy are provided.
[0005] The above objective is accomplished by a method and apparatus according to the present
invention.
[0006] In one aspect, the present invention relates to an energy handling system for converting,
storing or transmitting energy. The energy handling system comprises a heat exchange
unit for exchanging heat between a first substance and a second substance. The heat
exchange unit comprises a first inner compartment and a second outer compartment.
The first inner compartment and the second outer compartment are positioned adjacent
each other and are being separated by a heat exchange surface. The heat exchange unit
also comprises a balloon being mounted in the first inner compartment so as to form
in the first inner compartment a hermetically sealed volume between the outer surface
of the balloon and the heat exchange surface. The hermetically sealed volume is being
filled with the first substance and the balloon is being configured for being filled
with a balloon fluid. The second outer compartment is being filled with the second
substance.
[0007] The area of the heat exchange surface that is in contact with the first substance
and the second substance remains substantially the same during the heat exchange process.
It is an advantage of embodiments of the present invention that the energy handling
system is based on a unit, which may be referred to as a HBVI-unit (Hydraulic Balloon
Vessel Interface), which is a unit providing substantially the same heat exchange
surface area during the heat exchange process. This unique characteristic results
in the fact that the energy conversion system can be performed with a high efficiency,
i.e. with high yield. It is for example an advantage of systems according to embodiments
of the present invention that little or no losses occur due to friction, since the
HBVI unit does not substantially suffer from surfaces that are in contact with each
other. The first inner compartment also may be referred to as the vessel. Where in
embodiments of the present invention reference is made to the surface area of the
heat exchange surface being substantially the same during the heat exchange process,
this means that at least during 90% (for example during 95% or during 98%) of the
time of heat exchange in the system, the surface area of the heat exchange surface
that is in contact with the first substance and the second substance varies less than
10% (for example varies less than 5%, for example less than 2%).
[0008] According to some embodiments of the present invention, the system may furthermore
comprise a controller for controlling one of the volume of the balloon fluid in the
balloon or the second substance in the second outer compartment, for inducing a heat
exchange at the heat exchange surface.
[0009] The controller may be programmed for controlling the heat exchange process to occur
under substantially isentropic, isobaric, isothermic and/or polytropic conditions,
during at least 50% of the heat exchange process, advantageously during at least 60%
of the heat exchange process or at least 75% of the heat exchange process or at least
90% of the heat exchange process. It is an advantage of at least some embodiments
of the present invention that the conditions under which the heat exchange process
can occur can be fully controlled, so that a substantially isothermic process, a substantially
isentropic process, a substantially isobaric process, a polytropic process or a combination
thereof can be selected and fully controlled.
[0010] The controller may be programmed for controlling the heat exchange process to occur
under substantially the same temperature. In one particular example operation at a
substantially constant temperature can for example be obtained, which may advantageously
result in especially efficient heat exchange.
[0011] According to some embodiments, the balloon may be fixed at two positions in the first
inner compartment to form the hermetically sealed volume but to further not touch
the walls of the first inner compartment during the heat exchange process. It is an
advantage of embodiments of the present invention that energy storage and/or energy
conversion can be performed with low losses. It is for example an advantage that the
system is not based on a moving piston, since the latter results in friction losses.
[0012] It is an advantage of embodiments of the present invention that by the use of a balloon
in a vessel unit as configured as indicated in embodiments the present invention,
the amount of dead space in the system is close to zero, resulting in an efficient
energy conversion wherein nearly the full volume of the system is used for energy
conversion.
[0013] The balloon may be pre-shaped so that the shape of the balloon, when the balloon
is filled, fills a large part of the volume of the first inner compartment without
touching the first inner compartment except at the two fixation points.
[0014] The balloon may be fixed in a pre-tensioned manner. It is an advantage of embodiments
of the present invention that by fixing the balloon in a pre-tensioned manner, it
is assured that no or less contact is present between the balloon and the vessel,
also upon filling the balloon with the balloon fluid, thus allowing the area of the
heat exchange surface to be and remain substantially constant during the heat exchange
process.
[0015] According to at least some embodiments, the heat exchange process may be controlled
for occurring at a pressure in the range 200 to 700 bar, e.g. in the range 200 to
400 bar. It is an advantage of embodiments of the present invention that the pressure
at which the heat exchange process is controlled may be selected so that an especially
efficient system is obtained. It is an advantage of embodiments of the present invention
that the pressure at which the heat exchange process is controlled may be selected
so that the system can be kept compact in size.
[0016] The heat exchange process may be controlled for occurring with a maximum volume exchange
of the balloon in the range 1.5 to 2.5 times, e.g. in the range 1.75 to 2.25 times.
The balloon may be made of a material allowing extension towards at least 250% of
its volume, e.g. at least 300% of its volume, e.g. at least 350% of its volume, e.g.
at least 400% of its volume, without breaking.
[0017] The second outer compartment may be isolated from the outer world by an isolation
tube. The isolation tube may be an isolation tube providing an additional cavity around
the second outer compartment, whereby the additional cavity may be under vacuum or
for example filled with an isolation fluid.
[0018] The heat exchange surface may be made of a pressure resistant material. The heat
exchange surface may be made of any type of material such as for example a metal like
aluminum, a metal composite, or alike. Selection of the material may depend on the
temperature at which processing will be performed. Embodiments of the present invention
are not limited by the materials that is selected, provided they are resistant to
the pressures and the temperatures used for performing the heat exchange process.
[0019] The balloon fluid may be oil. The first substance may in some embodiments be a liquid,
e.g. water.
[0020] The first substance may in some embodiments be a supercritical gas.
[0021] The second substance may be a liquid. The second substance may be a cold liquid or
may be a warm liquid. In some embodiments, the second substance may be a gas. The
heat exchange unit may be substantially cylindrically shaped and the first inner compartment
and the second outer compartment may be configured as substantially concentric compartments.
The compartments may be substantially cylindrically shaped. Alternatively, the compartment
also may have any other suitable shape, such as for example droplet shaped.
[0022] The system may comprise a pumping unit for controlling the volume of the balloon
fluid in the balloon.
[0023] In some embodiments, the heat exchange unit may be configured for allowing the system
to operate as a compressor.
[0024] In some embodiments, he heat exchange unit may be configured for allowing the system
to operate as an expander.
[0025] In one aspect, the present invention also relates to a method of handling energy,
the method comprising inducing a heat exchange process using an energy handling system
as described in the first aspect.
[0026] Although there has been constant improvement, change and evolution of devices in
this field, the present concepts are believed to represent substantial new and novel
improvements, including departures from prior practices, resulting in the provision
of more efficient, stable and reliable devices of this nature.
[0027] The above and other characteristics, features and advantages of the present invention
will become apparent from the following detailed description, taken in conjunction
with the accompanying drawings, which illustrate, by way of example, the principles
of the invention. This description is given for the sake of example only, without
limiting the scope of the invention. The reference figures quoted below refer to the
attached drawings.
Brief description of the drawings
[0028]
FIG. 1 is a schematic representation of an energy handling system in accordance with
embodiments of the present invention.
FIG. 2 is an example of a hydraulic balloon - vessel interface system as can be used
in an energy handling system according to embodiments of the present invention.
FIG. 3 illustrates cross-sectional views of different hydraulic balloon-vessel interface
systems, according to embodiments of the present invention.
FIG. 4 illustrates different ways for connecting the balloon in the vessel in a pretensed
manner, according to embodiments of the present invention.
FIG. 5 illustrates conditions under which an energy handling system according to embodiments
of the present invention can be operated, thus resulting in a polytropic process (lefthand
side), an isobaric process (central image) and an isothermic process (righthand side).
[0029] In the different figures, the same reference signs refer to the same or analogous
elements.
Description of illustrative embodiments
[0030] The present invention will be described with respect to particular embodiments and
with reference to certain drawings, but the invention is not limited thereto but only
by the claims. The drawings described are only schematic and are non-limiting. In
the drawings, the size of some of the elements may be exaggerated and not drawn on
scale for illustrative purposes. The dimensions and the relative dimensions do not
correspond to actual reductions to practice of the invention.
[0031] Furthermore, the terms first, second, third and the like in the description and in
the claims, are used for distinguishing between similar elements and not necessarily
for describing a sequence, either temporally, spatially, in ranking or in any other
manner. It is to be understood that the terms so used are interchangeable under appropriate
circumstances and that the embodiments of the invention described herein are capable
of operation in other sequences than described or illustrated herein.
[0032] Moreover, the terms top, bottom, over, under and the like in the description and
the claims are used for descriptive purposes and not necessarily for describing relative
positions. It is to be understood that the terms so used are interchangeable under
appropriate circumstances and that the embodiments of the invention described herein
are capable of operation in other orientations than described or illustrated herein.
[0033] It is to be noticed that the term "comprising", used in the claims, should not be
interpreted as being restricted to the means listed thereafter; it does not exclude
other elements or steps. It is thus to be interpreted as specifying the presence of
the stated features, integers, steps or components as referred to, but does not preclude
the presence or addition of one or more other features, integers, steps or components,
or groups thereof. The term "comprising" therefore covers the situation where only
the stated features are present and the situation where these features and one or
more other features are present. The word "comprising" according to the invention
therefore also includes as one embodiment that no further components are present.
Thus, the scope of the expression "a device comprising means A and B" should not be
interpreted as being limited to devices consisting only of components A and B. It
means that with respect to the present invention, the only relevant components of
the device are A and B.
[0034] Similarly, it is to be noticed that the term
"coupled", also used in the claims, should not be interpreted as being restricted to direct
connections only. The terms "coupled" and "connected", along with their derivatives,
may be used. It should be understood that these terms are not intended as synonyms
for each other. Thus, the scope of the expression "a device A coupled to a device
B" should not be limited to devices or systems wherein an output of device A is directly
connected to an input of device B. It means that there exists a path between an output
of A and an input of B which may be a path including other devices or means. "Coupled"
may mean that two or more elements are either in direct physical or electrical contact,
or that two or more elements are not in direct contact with each other but yet still
co-operate or interact with each other.
[0035] Reference throughout this specification to "one embodiment" or "an embodiment" means
that a particular feature, structure or characteristic described in connection with
the embodiment is included in at least one embodiment of the present invention. Thus,
appearances of the phrases "in one embodiment" or "in an embodiment" in various places
throughout this specification are not necessarily all referring to the same embodiment,
but may. Furthermore, the particular features, structures or characteristics may be
combined in any suitable manner, as would be apparent to one of ordinary skill in
the art from this disclosure, in one or more embodiments.
[0036] Similarly it should be appreciated that in the description of exemplary embodiments
of the invention, various features of the invention are sometimes grouped together
in a single embodiment, figure, or description thereof for the purpose of streamlining
the disclosure and aiding in the understanding of one or more of the various inventive
aspects. This method of disclosure, however, is not to be interpreted as reflecting
an intention that the claimed invention requires more features than are expressly
recited in each claim. Rather, as the following claims reflect, inventive aspects
lie in less than all features of a single foregoing disclosed embodiment. Thus, the
claims following the detailed description are hereby expressly incorporated into this
detailed description, with each claim standing on its own as a separate embodiment
of this invention.
[0037] Furthermore, while some embodiments described herein include some but not other features
included in other embodiments, combinations of features of different embodiments are
meant to be within the scope of the invention, and form different embodiments, as
would be understood by those in the art. For example, in the following claims, any
of the claimed embodiments can be used in any combination.
[0038] Furthermore, some of the embodiments are described herein as a method or combination
of elements of a method that can be implemented by a processor of a computer system
or by other means of carrying out the function. Thus, a processor with the necessary
instructions for carrying out such a method or element of a method forms a means for
carrying out the method or element of a method. Furthermore, an element described
herein of an apparatus embodiment is an example of a means for carrying out the function
performed by the element for the purpose of carrying out the invention.
[0039] In the description provided herein, numerous specific details are set forth. However,
it is understood that embodiments of the invention may be practiced without these
specific details. In other instances, well-known methods, structures and techniques
have not been shown in detail in order not to obscure an understanding of this description.
[0040] The invention will now be described by a detailed description of several embodiments
of the invention. It is clear that other embodiments of the invention can be configured
according to the knowledge of persons skilled in the art without departing from the
technical teaching of the invention, the invention being limited only by the terms
of the appended claims.
[0041] In a first aspect, the present invention relates to an energy handling system. Such
an energy handling system may be a system adapted for converting energy, storing energy,
transmitting energy, ... The energy handling system according to embodiments of the
present invention comprises at least one heat exchange unit for exchanging heat between
a first substance and a second substance. It is to be noted that the energy handling
system may comprise more than one heat exchange unit. The energy handling system may
be based on performing expansion or compression of a fluid or may perform a plurality
of such actions, resulting in the possibility for converting between different types
of energy, such as for example heat/cold, electric energy, mechanical energy, etc....
According to embodiments of the present invention, the heat exchange unit comprises
a first inner compartment and a second outer compartment. The first inner compartment
and the second outer compartment are positioned adjacent each other and are being
separated by a heat exchange surface. The heat exchange unit also comprises a balloon
being mounted in the first inner compartment so as to form in the first inner compartment
a hermetically sealed volume between the outer surface of the balloon and the heat
exchange surface. The hermetically sealed volume is being filled with the first substance
and the balloon is being configured for being filled with a balloon fluid. The second
outer compartment is being filled with the second substance. According to embodiments
of the present invention, the area of the heat exchange surface that is in contact
with the first substance and the second substance remains substantially the same during
the heat exchange process.
[0042] By way of illustration, embodiments not being limited thereto, an exemplary embodiment
of the present invention will further be discussed with reference to FIG. land FIG.
2.
[0043] FIG. 1 illustrates a schematic representation of an exemplary energy handling system
1. The energy handling system 1 is based on one or more heat exchange units 100, which
may be referred to as a HBVI-unit (Hydraulic Balloon Vessel Interface). The one or
more heat exchange units 100 may be used for performing compression and/or expansion
of a fluid, used in the energy handling action. The one or more heat exchange units
100 may be controlled by a controller 2. Such a controller may comprise any suitable
processor. In some embodiments, such a controller may be configured for controlling
fluids in the one or more heat exchange units, for inducing a heat exchange at the
heat exchange surface of the heat exchange units 100. The controller 2 may be programmed
for controlling the heat exchange process to occur under substantially isentropic,
isobaric, isothermic and/or polytropic conditions, during at least 50% of the heat
exchange process, advantageously during at least 60% of the heat exchange process
or at least 75% of the heat exchange process or at least 90% of the heat exchange
process. It is an advantage of at least some embodiments of the present invention
that the conditions under which the heat exchange process can occur can be fully controlled,
so that a substantially isothermic process, a substantially isentropic process, a
substantially isobaric process, a polytropic process or a combination thereof can
be selected and fully controlled. In one embodiment, the controller 2 may be programmed
for controlling the heat exchange process to occur under substantially the same temperature.
In one particular example operation at a substantially constant temperature can for
example be obtained, which may advantageously result in especially efficient heat
exchange. For controlling the fluids in the at least one heat exchange unit 100, the
energy handling system 1 may comprise one or more pumping systems 3.
[0044] FIG. 2 illustrates a heat exchange unit as can be used in embodiments of the present
invention. The heat exchange unit 100 allows for exchanging heat between a first substance
110 and a second substance 120. The first substance may in some embodiments be a liquid,
e.g. water. The first substance may in some embodiments be a supercritical gas. Furthermore,
additional interface liquids may be used to avoid anyt kind of contamination. The
heat exchange unit 100 comprises a first inner compartment 130 and a second outer
compartment 140. The first inner compartment 130 and the second outer compartment
140 are positioned adjacent each other and are separated by a heat exchange surface
150. The heat exchange surface 150, corresponding with the outer surface of the first
inner compartment 130, is defined by the outer surface of a vessel. Since high pressures
may be induced in the first inner compartment 130, the outer surface of the first
inner compartment 130, i.e. the heat exchange surface 150, typically may be made of
a pressure resistant material. Such a material may be any type of material such as
for example a metal like aluminum, a metal composite, or alike. Selection of the material
may also depend on the temperature at which processing will be performed. Embodiments
of the present invention are not limited by the materials that is selected, provided
they are resistant to the pressures and the temperatures used for performing the heat
exchange process.
[0045] The vessel may be substantially cylindrically shaped and the first inner compartment
and the second outer compartment may be configured as substantially concentric compartments.
The compartments may be substantially cylindrically shaped. Alternatively, the compartment
also may have any other suitable shape, such as for example droplet shaped. The second
outer compartment may be formed conformally with the first inner compartment. In some
embodiments, the compartments also may have other shapes. FIG. 3 illustrates by way
of illustration and embodiments not being limited thereto, two examples of cross-sections
for the vessels that can be used, a first one for a cylindrically shaped vessel and
a second one for an alternatively shaped vessel, having a larger heat exchange surface
area.
[0046] According to the exemplary embodiment shown in FIG. 2, a balloon 160 is being mounted
in the first inner compartment 130 so as to form in the first inner compartment 130
a hermetically sealed volume 170 between the outer surface of the balloon 160 and
the heat exchange surface 150. The balloon 160 may be made of any suitable material
such as rubber materials suited for the temperature ranges and the fluids that are
applied. The material may be selected as function of the temperature that will be
used in the system. Advantageously, the balloon 160 is fixed at two positions in the
first inner compartment 130 to form the hermetically sealed volume 170 but to further
not touch the walls (or touch them as little as possible) of the first inner compartment
130 during the heat exchange process. The balloon 160 may be fixed in a pre-tensioned
manner. By way of example, embodiments not being limited thereto, four different ways
of connecting the balloon to the vessel are illustrated. In example A of FIG. 4, the
balloon is connected to the vessel via a ring shaped fixation means. In example B
of FIG. 4, a connection with a larger fixation area between the balloon and the vessel
is shown. In examples C and D of FIG. 4, a connection to the wider portion of the
vessel is obtained. In the examples C and D of FIG. 4, a connection element that fits
at one side to the vessel shape is used. The connection element is provided with an
introduction tube, allowing the balloon fluid to be introduced from outside the vessel
into the balloon.
[0047] The balloon 160 typically may be filled with a balloon fluid 180. The balloon fluid
180 may be oil, although embodiments are not limited thereto. The balloon fluid 180
may be pumped towards the balloon or away from the balloon 160 in the energy handling
system. The balloon is configured such with respect to the inner compartment that
it forms the hermetically sealed volume 170 that is filled with the first substance
110. In some embodiments, the balloon may be pre-shaped so that, when enlarging due
to pumping with balloon fluid, it enlarges with a similar shape as the heat exchange
surface. The balloon also may be pre-shaped so as to compensate for gravity forces
working on the balloon and the balloon fluid. The heat exchange process may be controlled
for occurring with a maximum volume exchange of the balloon 160 in the range 1.5 to
2.5 times, e.g. in the range 1.75 to 2.25 times.
[0048] The second outer compartment 140 is, in embodiments according to the present invention,
being filled with the second substance 130. The second substance may be a liquid.
The second substance may be a cold liquid or may be a warm liquid. In some embodiments,
the second substance may be a gas. The second outer compartment 140 may in some embodiments
be isolated from the outer world by an isolation tube 190. The isolation tube may
be an isolation tube providing an additional cavity around the second outer compartment,
whereby the additional cavity may be under vacuum or for example filled with an isolation
fluid.
[0049] According to embodiments of the present invention, the area of the heat exchange
surface 150 that is in contact with the first substance 110 and a second substance
120 remains substantially the same during the heat exchange process. By providing
substantially the same heat exchange surface area during the heat exchange process,
the energy conversion system can be performed with a high efficiency, i.e. with high
yield. Where reference is made to the surface area of the heat exchange surface being
substantially the same during the heat exchange process, this means that at least
during 90% (for example during 95% or during 98%) of the time of heat exchange in
the system, the surface area of the heat exchange surface that is in contact with
the first substance and the second substance varies less than 10% (for example varies
less than 5%, for example less than 2%).
[0050] As indicated above, the energy handling system may be equipped with a controller
and the heat exchange unit may be controlled to induce a heat exchange process at
the heat exchange interface. The heat exchange process may be controlled to occur
at a pressure in the range 200 to 700 bar, e.g. in the range 200 to 400 bar. Further
as indicated above, the heat exchange process may be controlled to operate substantially
isothermic process, a substantially isentropic process, a substantially isobaric process,
a polytropic process or a combination thereof. By way of illustration, embodiments
not being limited thereto, an example of such processes is shown in FIG. 5. In the
example shown on the left hand side of FIG. 5, a polytropic process is shown. In the
central portion of FIG. 5, an isobaric process is shown, where the pressure can be
kept substantially constant. Furthermore, on the righthand side of FIG. 5, an isothermal
process is shown, where the temperature can be kept constant.
[0051] In one aspect, the present invention also relates to a method of handling energy,
the method comprising inducing a heat exchange process using an energy handling system
as described in the first aspect. According to embodiments of the present invention,
the heat exchange process may be performed in a substantially isothermic process,
a substantially isentropic process, a substantially isobaric process, a polytropic
process or a combination thereof. The process advantageously can be performed in such
a manner that the heat exchange surface between the first and second substance in
contact with these substances remains substantially equal during substantially the
full heat exchange process.
[0052] It is to be understood that although preferred embodiments, specific constructions
and configurations, as well as materials, have been discussed herein for devices according
to the present invention, various changes or modifications in form and detail may
be made without departing from the scope of this invention. Steps may be added or
deleted to methods described within the scope of the present invention.
1. An energy handling system (1) for converting, storing or transmitting energy, the
energy handling system (1) comprising
a heat exchange unit (100) for exchanging heat between a first substance (110) and
a second substance (120), the heat exchange unit (100) comprising a first inner compartment
(130) and a second outer compartment (140), the first inner compartment (130) and
the second outer compartment (140) being positioned adjacent each other and being
separated by a heat exchange surface (150),
a balloon (160) being mounted in the first inner compartment (130) so as to form in
the first inner compartment (130) a hermetically sealed volume (170) between the outer
surface of the balloon (160) and the heat exchange surface (150), the hermetically
sealed volume (170) being filled with the first substance (110), the balloon (160)
being configured for being filled with a balloon fluid (180) the second outer compartment
(140) being filled with the second substance (130), characterised in that
the area of the heat exchange surface (150) that is in contact with the first substance
(110) and a second substance (120) remains substantially the same during the heat
exchange process.
2. An energy handling system (1) according to claim 1, wherein the system furthermore
comprises a controller for controlling one of the volume of the balloon fluid (180)
in the balloon (160) or the second substance (120) in the second outer compartment
(140), for inducing a heat exchange at the heat exchange surface (150).
3. An energy handling system (1) according to claim 2, wherein the controller is programmed
for controlling the heat exchange process to occur under substantially isentropic,
isobaric, isothermic and/or polytropic conditions, during at least 50% of the heat
exchange process, advantageously during at least 60% of the heat exchange process
or at least 75% of the heat exchange process or at least 90% of the heat exchange
process.
4. An energy handling system (1) according to any of claims 1 to 2, wherein the controller
is programmed for controlling the heat exchange process to occur under substantially
the same temperature.
5. An energy handling system (1) according to any of the previous claims, wherein the
balloon (160) is fixed at two positions in the first inner compartment (130) to form
the hermetically sealed volume (170) but to further not touch the walls of the first
inner compartment (130) during the heat exchange process.
6. An energy handling system (1) according to the previous claim, wherein the balloon
(160) is fixed in a pre-tensioned manner.
7. An energy handling system (1) according to any of the previous claims, wherein the
heat exchange process is controlled for occurring at a pressure in the range 200 to
700 bar, e.g. in the range 200 to 400 bar.
8. An energy handling system (1) according to any of the previous claims, wherein the
heat exchange process is controlled for occurring with a maximum volume exchange of
the balloon (160) in the range 1.5 to 2.5 times, e.g. in the range 1.75 to 2.25 times.
9. An energy handling system (1) according to any of the previous claims, wherein the
second outer compartment (140) is isolated from the outer world by an isolation tube
(190).
10. An energy handling system (1) according to any of the previous claims, wherein the
heat exchange surface (150) is made of a pressure resistant material.
11. An energy handling system (1) according to any of the previous claims, wherein the
balloon fluid (180) is oil and wherein the first substance (110) is a liquid, e.g.
water.
12. An energy handling system (1) according to any of the previous claims, wherein the
first substance (110) is a supercritical gas.
13. An energy handling system (1) according to any of the previous claims, wherein the
system comprises a pumping unit for controlling the volume of the balloon fluid (180)
in the balloon (160).
14. An energy handling system (1) according to any of the previous claims, wherein the
heat exchange unit is configured for allowing the system (1) to operate as a compressor.
15. An energy handling system (1) according to any of the previous claims, wherein the
heat exchange unit is configured for allowing the system (1) to operate as an expander.