Patent Application
20180356163
The present invention relates to a device and to a system comprising the device for introducing heat energy into a body of water and for extracting heat energy from the body of water.
Furthermore, a method for heating and cooling a structure by means of a corresponding device is described.
Due to rising energy costs and due also to ecological aspects, it is becoming increasingly important to utilize natural energy sources, such as wind or solar energy, in order to minimize the use of fossil fuels. Since energy sources of this type often deliver the necessary energy only for certain periods of time, however (solar cells deliver no power at night; wind turbines stand still in still air), energy generated by means of natural energy sources is temporarily stored in times of an energy surplus in order to be able to utilize the energy at a later point in time, for example, at night.
So-called pumped-storage power plants, for example, have proven particularly suitable for this purpose. In this case, water is pumped into a storage basin at a higher elevation, for example, with the aid of power generated by means of wind turbines. If energy is required, the potential energy of the water can be utilized during the release of the water into a storage basin at a lower elevation for driving generators and, therefore, for generating electric current.
It has also been already proposed to temporarily store heat energy in water tanks in order to subsequently extract the heat energy from the water tank by means of a heat exchanger and utilize the heat energy.
The previously known methods undoubtedly have advantages over the utilization of exclusively fossil energy sources without a second thought. There is room for improvement here as well, however.
The problem addressed by the present invention is therefore that of providing a device and a system, as well as a method, with the aid of which a particularly efficient utilization of naturally occurring energy is possible.
The problem is solved by a device, a system, and the method having the features described below.
The device according to the invention is used, in principle, for introducing heat into a body of water and for extracting heat energy from the body of water, wherein the body of water can be, for example, an artificial pond or lake or a pumped-storage basin which is operatively connected to one or multiple wind turbines.
The device generally comprises a main body including an interior hollow space which is completely or partially closed, wherein the hollow space is dimensioned in such a way that the device floats when placed in the body of water. Preferably, the device comprises attachment points, via which the device can be fixed in position in the body of water.
Furthermore, the device comprises a water heat exchanger which is at least partially immersed in the body of water after the device has been placed into the body of water, and therefore the heat transfer fluid flowing through the heat exchanger is in thermally conductive contact with the body of water via one or multiple heat exchanger walls in order to enable an exchange of heat energy between the heat transfer fluid and the water of the body of water.
The water heat exchanger comprises an intake for the heat transfer fluid which can be, for example, glycol or another known heat transfer fluid, and a discharge for the heat transfer fluid. If the device is now connected, via a pipe system, to a heat pump located on land before the use of the device, heat transfer fluid can flow from the heat pump to the device via the pipe system. In the device, the heat transfer fluid enters the water heat exchanger through the intake, flows through the water heat exchanger and, finally, flows back to the heat pump via the pipe system. If the water of the body of water has a temperature which is higher than the temperature of the heat transfer fluid, the heat transfer fluid extracts heat energy from the body of water while passing through the water heat exchanger and conducts the heat energy to the heat pump which, in turn, extracts heat energy from the heat transfer fluid (in order to heat a building, for example).
Depending on the temperature of the heat transfer fluid and on the water temperature, it is possible (in the winter months, in particular) that the water surrounding the device changes its physical state and freezes into ice, wherein a particularly large amount of heat energy can be extracted from the water in this case. The body of water acts as an “ice accumulator” in this case.
In order to now supply the body of water with natural heat energy simultaneously or with delay, and, therefore, to heat the body of water again and melt any ice which may have formed, the device further comprises an air heat exchanger, by means of which heat energy from the ambient air can be introduced into the body of water. For this purpose, the air heat exchanger comprises an air inlet for taking in ambient air and an air outlet for discharging the ambient air previously having entered the air heat exchanger through the air inlet, and therefore the ambient air can flow through the air heat exchanger. In order to force this flow, if necessary, it is provided that the device comprises at least one fan, by means of which ambient air can be displaced through the air inlet into the air heat exchanger and then through the air heat exchanger. The fan is a ventilator or a blower. The air heat exchanger further comprises an inlet for water originating from the body of water and an outlet for the water fed in via the inlet, and therefore water from the body of water can flow through the air heat exchanger and then exit the air heat exchanger.
While the aforementioned water heat exchanger is therefore utilized for extracting heat energy from the body of water and conducting the heat energy to a heat pump placed on land, the task of the air heat exchanger is to extract heat energy from the ambient air surrounding the device and introduce the heat energy into the water of the body of water. For this purpose, the air heat exchanger comprises one or multiple partitions, by means of which the water passing through the air heat exchanger is spatially separated from the ambient air which is also passing through the air heat exchanger, wherein the transfer of the heat energy from the ambient air to the water takes place via the partition or the partitions.
While the aforementioned utilization is useful in times in which the structure (school, gymnasium, apartment building, industrial building, etc.) connected to the device is to be heated, the device can also be utilized for cooling a structure, preferably in the summer. In this case, it is possible to operate the fan when the temperature of the ambient air is lower than the temperature of the water of the body of water surrounding the device. As a result, heat energy is transferred from the water to the ambient air and, therefore, the body of water cools down. If a heat transfer fluid which is delivered from the structure and has a temperature which is higher than the temperature of the body of water is now pumped through the water heat exchanger, preferably during the day, heat energy from the heat transfer fluid is given off to the body of water. The cooled heat transfer fluid can finally be pumped back to the structure and, therefore, can be fed to a cooling circuit of the structure.
It is advantageous when the device comprises a main body forming the hollow space. The device is designed, in principle, as a pontoon and preferably comprises a power connector for the power supply of the ventilator and comprises connection points to the intake and to the discharge for the connection of a pipe system, via which the water heat exchanger can be supplied with a heat transfer fluid. Preferably, the main body is completely or at least mostly made of concrete in order to provide for a low-cost, stable, and durable design. The heat exchanger sections of the air heat exchanger, which are designed to be tubular, in particular, preferably extend within the main body, in particular within the aforementioned hollow space, wherein water originating from the body of water flows through the aforementioned heat exchanger sections during the operation of the device. For this purpose, the device itself comprises a pump. Alternatively, the device can also be connected via the aforementioned intake to a corresponding line, via which water can be fed to the water heat exchanger by means of an external pump.
It is advantageous when the water heat exchanger is immersed into the body of water below the main body of the device when the device is used as intended. The immersed sections of the water heat exchanger (which should be sections, of course, through which the heat transfer fluid can flow) come into direct contact with the water below the device in this case, wherein the transfer of the heat energy between the water and the heat transfer fluid takes place via corresponding walls of the immersed sections of the water heat exchanger. Since the immersed sections are preferably located exclusively below the device or the main body thereof, damage caused by passing boats/ships is nearly entirely ruled out.
Particular advantages result when the water heat exchanger comprises one or multiple tube sections through which the heat transfer fluid can flow and which are immersed into the body of water at least in sections when the device is used as intended and, therefore, form the aforementioned sections. Preferably, the tube sections are designed in a meander shape, a spiral shape, or a serpentine shape in order to provide a heat exchanger surface which is as large as possible, on the smallest possible space. The tube sections can be formed by several tubes or, jointly, can form one tube through which the heat transfer fluid flows. In any case, the tube sections are connected to the intake and to the discharge of the water heat exchanger, and therefore the heat transfer fluid can flow into the tube sections and exit the tube sections.
It is advantageous when the device comprises a protective wall which is immersed into the body of water and laterally protects the heat exchanger element(s) immersed into the body of water. The protective wall can extend, apron-like, from the main body downward into the body of water and prevents flotsam from impacting laterally against the sections of the water heat exchanger protruding into the water and damaging the water heat exchanger. The protective wall is preferably provided as a separate component which is connected to the main body and, for example, laterally partially or completely surrounds the main body (as collision protection).
Particular advantages result when the device comprises sections which protrude from the body of water when the device is used as intended. The device is therefore designed, in particular, in such a way that one part of the device is located above and one part of the device is located below the water level of the body of water. In particular, it is advantageous when the fan (several of which can also be present, in general) is disposed in the region of a section protruding from the body of water in order to allow for a particularly simple maintenance of the fan. Alternatively, the fan can also be placed within the device, of course, wherein the fan is more difficult to access in this case.
It is also advantageous when the fan is disposed in the region of the air inlet or of the air outlet. The fan is visible from above, in particular during the operation of the device, and, for example, is covered by a grid. Furthermore, the fan should comprise a connector for an electrical power supply, in particular for a power cable, in order to enable the fan to be connected to an external power source which is preferably disposed on land.
Particular advantages result when the device comprises sections which protrude from the body of water when the device is used as intended and laterally delimit a surface section of the body of water at least in sections. As a result, a volume of water, which is closed toward the side to a more or less extreme extent, is delimited. The water present in this region can be heated particularly intensively by sunlight and can finally give off its heat energy to the device located therebelow and, in particular to the air heat exchanger, and therefore the water flowing through the air heat exchanger can be additionally heated.
In this context, it is of particular advantage when a cover section of the device extends between the aforementioned sections and is below the water surface of the body of water when the device is used as intended and is at least partially visible from above The cover section can delimit, in particular, the interior hollow space toward the top. The interior hollow space, in turn, entirely or partially encloses the air heat exchanger. The region of the hollow space disposed above the cover section, which is covered by a certain volume of water, can therefore be heated by the water. If ambient air is now transported through the hollow space via the air inlet and the air outlet, this ambient air is additionally heated by the heated cover section, and therefore a particularly large amount of heat energy can be introduced into the water of the body of water.
It is also advantageous when the outlet of the air heat exchanger extends in the region of the cover section, and therefore water exiting the air heat exchanger via the outlet can flow across the cover section back into the body of water. In particular, the cover section or a section thereof enclosing the outlet thereof should be located above the water surface when the device is used as intended (i.e., after having been placed into a body of water). In any case, a placement of the outlet in the region of the cover section, which is visible from above, in principle, has the advantage that the exiting water can be additionally heated by solar energy on the surface of the device after having exited the air heat exchanger. The introduction of natural heat energy is the maximum in this case.
Particular advantages result when the cover portion, together with the sections protruding from the body of water, forms a basin which is delimited toward the bottom and, at least in sections, also toward the side. Preferably, the basin is delimited toward all sides by sections protruding correspondingly from the body of water and is open toward the top. The water located in the basin, which can flow into the basin via the outlet of the air heat exchanger, can be intensively exposed to sunlight in this case and, therefore, can be additionally heated (the aforementioned outlet is preferably located in the region of the cover section or in the region of inwardly directed side walls of the sections of the device protruding from the body of water).
It is advantageous when the aforementioned water heat exchanger, preferably its tube sections through which the heat transfer fluid can flow, extends into the cover section and/or into the basin, and therefore heat energy can be transferred between the heat transfer fluid and the water located in the basin. If heat transfer fluid is now pumped through the water heat exchanger, the temperature of which is below 0° C., the water located in the basin cools rapidly and then freezes, and therefore a relatively large amount of heat energy can be transferred to the heat transfer fluid in a relatively short time. In this way, greater amounts of heat can be rapidly provided to the structure connected to the device, wherein this is of particular advantage at certain times of the day (for example, in the morning, in order to rapidly heat the structure).
Additionally or alternatively, a second water heat exchanger can also be provided, which also comprises an intake for a heat transfer fluid and a discharge for the heat transfer fluid (wherein the intake and the discharge are connected or can be connected to the first water heat exchanger or to a separate pipe system). For example, it would be conceivable that the first water heat exchanger or its tube sections extend exclusively into the water of the body of water under the main body, while the second water heat exchanger or its tube sections, through which a heat transfer fluid can flow, extend exclusively into the basin and/or the cover section of the device and/or into the sections thereof protruding from the water.
The system according to the invention finally comprises a device floating in a body of water, according to the preceding or the following descriptions, wherein the individual features can be implemented individually or in any combination (provided the features of claim 1 have been implemented). Furthermore, the system comprises a heat pump which is disposed outside the body of water, i.e., on land, and is connected to the device via a pipe system (preferably comprising a supply line and a return line), wherein the heat pump can be placed, for example, in a structure (a building, or the like). The heat pump is used for extracting heat energy from the heat transfer fluid flowing back from the device via the pipe system in order to heat the structure. In particular, the heat pump and the device are connected as a circuit via the pipe system, and therefore the heat transfer fluid can circulate between the heat pump and the device.
Particular advantages result when the system comprises multiple devices according to the preceding or the following descriptions. The individual devices can be placed independently of each other in the body of water and can each be connected to one or multiple heat pumps via a separate line network or the same line network. Preferably, however, multiple devices are connected to each other to form one floating unit. In particular, in this case, the particular air heat exchanger and/or water heat exchanger should also be coupled to each other, and therefore ambient air and/or heat transfer fluid and/or water from the body of water can flow through multiple devices in a parallel or series connection.
The method, which has already been described in part, for heating a structure by means of a device according to the preceding or the following description therefore includes the following steps:
Initially, the device is placed in a previously selected body of water, for example, a (pumped-) storage lake and, there, is fixed to the bottom of the body of water, if necessary. Subsequently, the device is connected to a heat pump located on land, and therefore, in the end, the above-described system is obtained.
In order to now introduce heat energy from the ambient air surrounding the device into the water of the body of water and therefore temporarily store the heat energy, the aforementioned fan is set into operation, and therefore ambient air is displaced through the air heat exchanger. Preferably simultaneously or with delay, a pump is activated (which does not need to be part of the device) in order to pump water out of the body of water and feed the water to the air heat exchanger.
Given that the region through which the water flows and the region of the air heat exchanger through which the ambient air flows are separated from each other merely by a partition, heat energy from the ambient air is transferred to the water (provided, of course, that the temperature of the ambient air is higher than the temperature of the water passing through the air heat exchanger).
Simultaneously or preferably at least partially with delay (for example, at night), the heat transfer fluid is finally also pumped through the water heat exchanger and thereby extracts heat energy from the water of the body of water, which can be finally given off by the heat pump to a heating circuit of the structure to be heated. In this case, the heat transfer fluid is pumped from the heat pump, through the water heat exchanger, and back to the heat pump, wherein heat energy from the water originating from the body of water is transferred to the heat transfer fluid in the region of the device and then transferred with the aid of the heat pump from the heat transfer fluid to a heating circuit of the structure in order to heat up the structure.
Advantages result when operating the fan, displacing the water originating from the body of water through the air heat exchanger, and/or displacing the heat transfer fluid through the water heat exchanger occur as a function of the heating demand of the structure and/or of the temperature of the ambient air and/or of the temperature of the body of water. In particular, the fan can be controlled and/or regulated by means of a control and/or regulating unit. For example, it would be useful to operate the fan only when the temperature of the ambient air is higher than the temperature of the water surrounding the device, if heat energy from the ambient air is to be fed to the body of water.
Alternatively, the device can also be used for cooling a structure, i.e., for extracting heat energy from the structure and introducing the heat energy into the body of water. The corresponding method comprises the following steps:
Initially, in this case as well, the device (having the features described in the preceding or in the following) must be introduced into a body of water (provided this has not already happened, since the device has already been used for the method described above). The device must also be connected to a cooling circuit—which is located on land—of the structure to be cooled (if this has not already taken place within the scope of the method described above, wherein the cooling circuit can be connected to the aforementioned heat pump).
In order to now bring about a cooling of the body of water, the fan is operated, and therefore ambient air is displaced through the air heat exchanger. In this case, the fan should be operated only when the temperature of the ambient air is lower than the temperature of the water of the body of water surrounding the device, however, since heat energy can be transferred from the water to the ambient air only in this case. The fan should therefore be operated preferably at night.
At the same time, water should be pumped through the air heat exchanger in order to provide for the desired transfer of heat energy from the water to the ambient air. The body of water cools down in this way. If a heat transfer fluid is now pumped through the water heat exchanger, the temperature of which is higher than the temperature of the water surrounding the device, the heat transfer fluid can give off the heat energy, which was previously taken up in the structure, to the body of water via the water heat exchanger and, therefore, cools down. The cooled heat transfer fluid, after having passed through the water heat exchanger, is finally pumped back to the building via the pipe system and can cool the building via its cooling circuit.
It is also advantageous in this context when operating the fan, displacing the water originating from the body of water through the air heat exchanger, and/or displacing the heat transfer fluid through the water heat exchanger occur as a function of the cooling demand of the structure and/or of the temperature of the ambient air and/or of the temperature of the body of water.
Furthermore, the aforementioned methods can also be combined, of course, wherein the initially mentioned method should be carried out in times in which the structure is to be heated (for example, in the winter months), while the method described second should be implemented when the building is to be cooled (preferably, therefore, in the summer months).
Further advantages of the invention are described in the following exemplary embodiments. Schematically:
The body of water 2 is, in principle, a standing, preferably artificial body of water 2, such as a reservoir which can be connected to one or multiple wind turbine towers via an incoming line 20 and an outgoing line 21, with the aid of which water 25 can be pumped into the body of water 2 or out of the body of water, and therefore the body of water 2 can be utilized as a pumped-storage lake.
The device 1 utilized according to the invention is designed, in principle, to float, and therefore, as shown in
Furthermore, the device 1 is connected to a pipe system 16 (which preferably comprises at least two pipes) which, in turn, is connected to a heat pump 15 of a structure 17, for example, an office or apartment building, located on the land 22. The heat pump 15, in turn, can be connected to a heating circuit 18 and/or a cooling circuit 19, via which the structure 17 can be finally supplied with heat energy or can be cooled.
The device 1 itself will now be explained in greater detail with reference to
In principle, the device 1 comprises a main body 31 which is made, preferably entirely or in part, of concrete and delimits a hollow space 3 in order to provide the device 1 with the necessary buoyancy in the water 25 of the body of water 32.
Extending within the hollow space 3 is an air heat exchanger 7 which preferably comprises one or multiple heat exchanger tubes 32, through which water 25 of the body of water 2 can flow. For this purpose, the air heat exchanger 7 comprises an inlet 11 which is connected to a line 28 which is only incompletely represented and, in turn, is connected to a pump, with the aid of which water 25 can be pumped from the body of water 2 into the water heat exchanger 4. The water 25 flows through the heat exchanger tubes 32 and finally exits the water heat exchanger 4 via an outlet 12. The outlet 12 is preferably located in the region of a cover section 26 of the device 1, which faces upward and preferably extends below the water level 24, and therefore the exiting water 25 can be additionally heated with the aid of sunlight.
The main heat input into the body of water 2 takes place via the air heat exchanger 7, however, the fan 10 of which draws in ambient air via an air inlet 8 and conducts the air into the hollow space 3 during the operation of the device 1. In the hollow space 3, the air comes into contact with the outer wall of the heat exchanger tubes 32 acting as a partition 13, and therefore heat energy from the ambient air can be transferred to the water 25 flowing through the heat exchanger tubes 32. The body of water 2 is heated as a result (reference is made to the description provided above with respect to the second possible use of the device 1, in which the body of water 2 is cooled by giving off heat energy to the ambient air).
Finally, the cooled ambient air exits the device 1 via an air outlet 9, wherein the air inlet 8 and the air outlet 9 should be located in the region of a section 27 of the device 1 protruding from the water 25.
While the air heat exchanger 7 is utilized, in the described case, for introducing heat energy from the surroundings into the body of water 2, the water heat exchanger 4, which is also represented, is utilized for extracting heat energy from the body of water 2 in order to conduct the heat energy to the building (in the opposite application, which is not explicitly described here, the air heat exchanger 7 is utilized for cooling the body of water 2 and the water heat exchanger 4 is utilized for introducing heat energy into the body of water 2).
The water heat exchanger 4 comprises one or multiple tube sections 29 which are immersed, entirely or partially, into the water 25 of the body of water 2. The water heat exchanger 4 also comprises an intake 5, via which a heat transfer fluid (for example, glycol) can be pumped from the heat pump 15 via the pipe system 16 into the water heat exchanger 4. The heat transfer fluid flows through the tube sections 29 and returns, via an outlet 6, into the pipe system 16 and, finally, back to the heat pump 15. If the heat transfer fluid flowing in via the intake 5 has a temperature which is lower than the temperature of the water 25 surrounding the tube sections 29, heat energy from the water 25 is transferred to the heat transfer fluid and can finally be utilized for heating the structure 17 via the heat pump 15. At the same time, the water 25 in the body of water 2 cools down, wherein, depending on the starting temperature of the body of water 2 and the temperature of the heat transfer fluid, this can even result in the water 25 surrounding the tube sections 29 freezing.
As is also finally clear from
This second water heat exchanger 4 is therefore located in a region, in which it can extract heat energy from the water 25 of the body of water 2 located above the cover section 26. In this case, the cover section 26, together with the sections 27 of the device 1 protruding from the water, forms a type of basin 14 which at least partially delimits a volume of water.
If heat energy is extracted from this water 25 via the second water heat exchanger 4, this volume of water can freeze rapidly, depending on the particular conditions, and therefore, due to the phase transition, a particularly large amount of heat energy per volume of water 25 can be extracted.
A second possible embodiment is shown in
In contrast to the embodiment shown in the previous figures, the main body 31 of the device 1 shown in
Furthermore,
Moreover, as shown, the second water heat exchanger 4 disposed in the basin 14 can comprise a separate intake 5 and a separate discharge 6 for a heat transfer fluid. In principle, the aforementioned water heat exchanger 4 and the water heat exchanger 4 protruding downward into the body of water 2 can also be coupled, of course, and therefore the heat transfer fluid can flow through both water heat exchangers 4 in the manner of a series or parallel circuit.
The present invention is not limited to the exemplary embodiments which have been represented and described. Modifications within the scope of the claims are possible, as is any combination of the described features, even if they are shown and described in different parts of the description or the claims or in different exemplary embodiments.
1 device for introducing heat into a body of water and for extracting heat from the body of water
2 body of water
3 hollow space
4 water heat exchanger
5 intake of the water heat exchanger
6 discharge of the water heat exchanger
7 air heat exchanger
8 air inlet of the air heat exchanger
9 air outlet of the air heat exchanger
10 fan
11 inlet of the air heat exchanger for the water originating from the body of water
12 outlet of the air heat exchanger for the water originating from the body of water
13 partition
14 basin
15 heat pump
16 pipe system
17 structure
18 heating circuit of the structure
19 cooling circuit of the structure
20 incoming line
21 outgoing line
22 land
23 rib
24 water level
25 water
26 cover section
27 section protruding from the body of water
28 line
29 tube section
30 protective wall
31 main body
32 heat exchanger tube
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 121 177.7 | Dec 2015 | DE | national |
This application claims priority to International Application Serial No. PCT/EP2016/079481, filed Dec. 1, 2016, which claims priority to German Application No. 110 2015 121 1777, filed Dec. 4, 2015. International Application Serial No. PCT/EP2016/079481 is hereby incorporated herein in its entirety for all purposes by this reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/079481 | 12/1/2016 | WO | 00 |
