SYSTEM FOR EXTRACTING THERMAL ENERGY

Abstract

The invention relates to a system for extracting thermal energy, a method for operating such a system and a thermal module for such a system. More particularly, the system is for extracting thermal energy from sunlight or other thermic energy sources.

Claims

1.-15. (canceled)

16. A system for extracting thermal energy having a plurality of thermal modules, each module having a housing comprising: a radiation absorber; at least one flow channel for a heat extraction medium, wherein the at least one flow channel is arranged adjacent to the radiation absorber; a flow adjustment actuator for transporting and/or controlling the flow of the heat extraction medium through the at least one flow channel; and a receiver connected to the flow adjustment actuator for receiving an output signal of at least one controller, the at least one controller for controlling the flow adjustment actuators in the plurality of thermal modules; and wherein the at least one controller is adapted to individually regulate the flow adjustment actuators of the plurality of modules depending on data stored in a memory unit connected to the controller.

17. The system according to claim 16, wherein the system further comprises at least one sensor for measuring a parameter selected from the group of temperature, pressure, flow rate and light.

18. The system according to claim 17, wherein the at least one controller is adapted to individually regulate the flow adjustment actuators of the plurality of modules depending on one or more signal(s) received from the at least one sensor.

19. The system according to claim 17, wherein the system comprises at least two sensors configured for measuring a parameter, the at least two sensors selected from the group consisting of temperature, pressure, flow rate and light; wherein the at least one controller is adapted to periodically receive at least two input signals from the at least two sensors and to individually regulate the flow adjustment actuators of the plurality of modules depending on the at least two signals received from the at least two sensors.

20. The system according to claim 17, wherein the at least one controller is adapted to regulate the flow adjustment actuators of the plurality of modules such that the parameter remains within predetermined boundaries.

21. They system according to claim 16, wherein at least one sensor is comprised in each module and is for measuring a parameter of the heat extraction medium.

22. The system according to claim 20, wherein the at least one controller is adapted to regulate the flow adjustment actuators of the plurality of modules such that the pressure of the heat extraction medium in the flow channel remains below 10 bar.

23. They system according to claim 20, wherein the at least one controller is adapted to regulate the flow adjustment actuators of the plurality of modules such that the temperature of the heat extraction medium is between 20 and 30° C. in a proximity of a flow channel outlet of a module.

24. The system according to claim 17, wherein the at least one controller is adapted to regulate the flow adjustment actuators of the plurality of modules depending on the light intensity measured by the at least one sensor.

25. The system according to claim 16, wherein the thermal module is a hybrid photovoltaic-thermal module and adapted to generate electric energy.

26. The system according to claim 16, wherein the photovoltaic area is larger than 50% of the absorber area.

27. The system according to claim 16, wherein the flow adjustment actuator is selected from the group consisting of a pump and a valve.

28. The system according to claim 16, wherein the flow adjustment actuator is a pump and the pump is operable in reverse such that the thermal module is heated.

29. A method for operating a system for extracting thermal energy comprising the steps of: a) heating a heat extraction medium in a plurality of flow channels disposed within a plurality of thermal modules, wherein the flow channels are arranged adjacent to radiation absorbers of the modules; b) adjusting the flow of the heat extraction medium in the flow channels of the modules by means of at least one flow adjustment actuator per module; c) measuring a parameter selected from the group of temperature, pressure, flow rate and light; d) controlling the at least one flow adjustment actuator per module with at least one controller based on the parameter; and e) removing heat by collecting the heat extraction medium, and/or by collecting a heat removal fluid which has been in thermic exchange with the heat extraction medium, from the individual modules.

30. The method according to claim 29, wherein the parameter is selected from the group consisting of a temperature, a pressure and a flow rate of the heat extraction medium; and the at least one controller is controlled such that a parameter of the heat extraction medium remains within predetermined boundaries.

31. The method according to claim 29, wherein the flow adjustment actuator is a pump and the method additionally comprises the step of reversing the flow direction of the heat extraction medium by reversing the operation mode of the pump, such that the thermal module is heated.

32. A thermal module for a system according to claim 16 comprising: a) a radiation absorber; b) at least one flow channel for a heat extraction medium, wherein the at least one flow channel is arranged adjacent to the radiation absorber; c) a flow adjustment actuator for transporting and/or controlling the flow of the heat extraction medium through the at least one flow channel; and d) a receiver connected to the flow adjustment actuator for receiving an output signal of a controller.

33. The thermal module according to claim 32, additionally comprising a controller for controlling the flow adjustment actuators in the solar thermal module, which controller is adapted to receive input signal(s) from a sensor and to regulate the flow adjustment actuators based thereon.

34. The thermal module according to claim 32 further comprising a sensor for measuring a parameter selected from the group of temperature, pressure, flow rate and light.

Description

[0080] The following figures show:

[0081] FIG. 1: Schematic view of a system for extracting thermal energy from sunlight;

[0082] FIG. 2: Perspective view on selected components of a thermal module;

[0083] FIG. 3: Perspective view on selected components of thermal module, including a connecting tube;

[0084] FIG. 4: Schematic view of a cross section through a heat exchanger tube;

[0085] FIG. 5: Schematic view of a longitudinal section through a heat exchanger tube;

[0086] FIG. 6: Schematic representation of a closed-circuit arrangement of a thermal module;

[0087] FIG. 7: Perspective view on selected components of a thermal energy module including an insulating layer;

[0088] FIG. 8: Perspective view on selected components of thermal energy module including a cover layer;

[0089] FIG. 9: Perspective view on selected components of thermal energy module including a solar panel of photovoltaic cells;

[0090] FIG. 1 shows a schematic view of a system for extracting thermal energy from sunlight. The system has a plurality of thermal modules 1,1′, which are located on top of a saddle roof of a building. Each module 1 has a housing. The components comprised in the housing (radiation absorber, at least one flow channel for a heat ex-traction medium, a flow adjustment actuator, receiver connected to the flow adjustment actuator for receiving an output signal 70 of at least one controller, and optionally: at least one sensor) are not shown in FIG. 1. At least one controller 5 for controlling the flow control actuators in the plurality of solar thermal modules is comprised in the system. The controller 5 receives data, which is stored in a memory unit 23 connected to the controller, and which may consist of, e.g. astronomic, climatic or meteorological data. The controller 5 additionally or alternatively receives one or more signals 7,7′ from at least one sensor. The sensor(s) may be comprised in the housing of a module (6, not shown) or there may be an ambient sensor(s) 14, purposefully placed to detect a parameter which is relevant for an entire region or cluster of the system. The controller 5 is adapted to individually regulate the flow adjustment actuators 4 of the plurality of modules 1 depending on the data received from the memory unit 23, and/or on the signal(s) 7 received from a sensor 6 comprised in the housing of a module, and/or on the signal(s) 7′ received from an ambient sensor 14. In order to regulate the flow adjustment actuators 4 of the plurality of modules 1, the controller 5 sends out an output signal 70 to the receivers of the modules 1,1′.

[0091] FIG. 2 shows a perspective view on selected components of a thermal energy module. Shown is a meandering flow channel 3 for a heat extraction medium, which is to be arranged adjacent to the radiation absorber (not shown). In this embodiment, the module is based on a closed circuit set-up with a heat exchanger portion. The straight linear part of the flow channel 3 forms the inner chamber 12 of a heat exchanger pipe. Also shown is a flow adjustment actuator, in particular a pump 4, for transporting the heat extraction medium through the flow channel 3. The flow adjustment actuator is connected to a receiver (not shown) for receiving an output signal 70 of at least one controller 5. The controller may be comprised in the housing of each module or may be located elsewhere for processing the data centrally. The boxes allotted over the length of the meandering flow channel 3 are sensors 6,6′,6″,6′″ for measuring a parameter selected from the group of temperature, pressure, flow rate and light.

[0092] FIG. 3 shows a perspective view on selected components of thermal module 1 as depicted in FIG. 2. In addition is shown a heat exchanger tube, including the outer chamber 11. The outer chamber 11 now surrounds the inner chamber 12 over the length of the heat exchanger portion. The outer chamber 11 of the heat exchanger portion at the same time forms the inlet 9 and outlet 10 pieces for connecting neighboring modules 1,1′ in parallel and/or in series. Such connection may be provided by connecting the connecting tube outlet 10 of an upstream module to the connecting tube inlet 9 of a downstream module or the connecting tube inlet 9 of a first module to a connecting tube inlet 9 of a parallel module. The connecting tube inlet 9 and a connecting tube outlet 10 may be adapted such that the modules can be brought into fluidic communication with each other. Furthermore, the outer chamber 11 of the heat exchanger pipe has an inlet opening for a return line 20 of the meandering flow channel 3 and an outlet opening for a feed line 21 into the module's meandering flow channel 3.

[0093] FIG. 4 shows a schematic view of a cross section through a heat exchanger tube. FIG. 5 shows a schematic view of a cross section through a heat exchanger tube in a longitudinal direction. The heat exchanger's inner chamber 12 is in fluid communication with the flow channel 3 and is surrounded by the outer chamber 11 of the heat exchanger. In this particular embodiment, the outer chamber of the heat exchanger has three compartments: The cold heat removal medium of a larger circuit flows into the lower compartment 60,60′ of the heat exchanger. Via an opening 50, the cold heat removal medium 40 passes, at least partially, into an intermediate compartment 61,61′ where the main part of the heat exchange occurs. Via another opening 51, the warmed heat removal medium 41 passes into a third, warm compartment 62,62′ in the upper part of the Figures and eventually leaves the module.

[0094] FIG. 6 shows a schematic representation of a closed-circuit arrangement of a thermal module. Again, the flow channel 3 is provided as a meandering tube. The heat extraction medium is conveyed by means of two pumps 4,4′. The pump rate of the pump is determined by a controller (not shown) based on the signals received from sensors 6,6′. The shown set-up is particularly suitable for a feedback loop where, for example, the temperature of the heat extraction medium is monitored periodically and the controller is adapted to regulate the pumps 4,4′ such that the temperature of the extraction medium remains between 23 to 27° C. in a proximity of the main tube 11′ of the heat exchanger portion, specifically at the position of the sensor 6′. In this embodiment, the module has two heat exchanger portions. The outer chamber 11 of the cooling portion provides cooling medium 6 at its inlet. The outer chamber 11′ of a heat removal portion removes warm medium 9′ at its outlet 10.

[0095] FIG. 7 shows a perspective view on selected components of a thermal energy module. The components are the same as depicted in FIG. 2. However, the flow channel 3, sensors and pump are provided on an insulating layer 30. FIG. 8 shows a perspective view on the components of the thermal module, covered by the radiation absorber 2. The flow channel 3 is placed directly underneath the radiation absorber 2 in order to allow optimized heat transfer. The inlet 9 and outlet 10 of the outer chamber of the heat exchanger portion are further equipped with connecting pieces.

[0096] FIG. 9 shows a perspective view on selected components of thermal module including a panel of photovoltaic cells 31. The solar thermal module is a hybrid photovoltaic-thermal (PVT) module and adapted to generate electric energy. In the present case, the solar thermal module is equipped with a 2×3 wafer (6″) and may have a total output of 28 W. Typical dimensions of such photovoltaic surface are 520 mm×360 mm. The current produced by the PV-cells may be used to run the energy-consuming elements of the thermal module. The panel pf PV cells may be provided under a glass plate in an aluminum frame. Each module may contain a junction box with a separating diode and cables (MC4-EU standard). The thermal module is a flat plate collector and its main layers are: the insulating layer 30, the radiation absorber 2 and the panel of photovoltaic cells 31, placed on top of each other.