BASE TROUGH FOR A THERMAL MODULE, THERMAL MODULE COMPRISING SUCH BASE TROUGH, A SYSTEM FOR EXTRACTING THERMAL ENERGY AND THE USE OF SUCH BASE TROUGH FOR EXTRACTING THERMAL ENERGY FROM SUNLIGHT

Abstract

The invention relates to a base trough (4) for a thermal module (1), thermal module (1) comprising such base trough (4), a system for extracting thermal energy and the use of such base trough (4) for extracting thermal energy from sunlight.

Claims

1. A base trough for a thermal module, configured to be covered by a radiation absorber plate or by the outermost layer of a photovoltaic (PV) cell arrangement, the said layer facing away from the sun, to form a heat exchanger portion of a flow channel adjacent to the radiation absorber plate or to the outermost layer of the PV cell arrangement, for a heat exchanger medium to flow through; wherein the base trough comprises a plurality of wall portions for contacting said radiation absorber plate or said outermost layer of the PV cell arrangement in a fluid-tight manner; a recess for forming a heat exchanger portion of the flow channel; a recess or tube for forming a feeding channel; a recess or tube for forming an outlet channel; wherein the recess for the heat exchanger portion of the flow channel has at least an open inlet which communicates with the feeding channel and at least an open outlet which communicates with the collecting channel, wherein the feeding channel and the collecting channel extend along opposed heads of the base trough, and wherein the mean depth of the heat exchanger portion of the fluid channel is smaller than the mean diameter of a cross-section through the feeding channel and smaller than the mean diameter of a cross-section through the collecting channel by at least a factor of 1.2.

2. The base trough for a thermal module according to claim 1, wherein the heat exchanger portion of the flow channel has a plurality of grooves for the heat exchanger medium to flow through, wherein the grooves are arranged in parallel to each other; and are arranged such that neighboring grooves are separated from one another in a longitudinal direction by elongated protrusions.

3. The base trough for a thermal module according to claim 2, wherein the cross-section through an individual groove is substantially V-shaped, substantially U-shaped, or has the shape of a semi-ellipse.

4. The base trough for a thermal module according to claim 2, wherein the mean cross-sectional area of the feeding channel is 2 to 10 times larger than the cross-sectional area of an individual groove; and/or wherein the mean cross-sectional area of the collecting channel is 2 to 10 times larger than the cross-sectional area of an individual groove.

5. The base trough for a thermal module according to claim 2, wherein the elongated protrusions of the heat exchanger portion are spaced apart from the radiation absorber plate or from the outermost layer of a photovoltaic cell arrangement, such that the heat exchanger medium is allowed to pass from one groove to the other over an elongated protrusion and to substantially completely wet the surface of the radiation absorber or outermost layer of a PV cell arrangement which is directed towards the flow channel.

6. The base trough for a thermal module according to claim 2, wherein the edge of an elongated protrusion which points towards the flow channel and separates a groove from a neighboring groove is spaced apart from the radiation absorber plate or from the outermost layer of a photovoltaic cell arrangement by 0.1 to 15 mm, preferably by 0.5 to 10 mm, more preferably by 1 to 5 mm.

7. The base trough for a thermal module according claim 1, wherein the base trough is of a material selected from the group consisting of ceramics; polymers; biomaterials; and metals; or a combination thereof.

8. The base trough for a thermal module according to claim 1, wherein the base trough, including the plurality of wall portions, the heat exchanger portion, the feeding channel, and the collecting channel are formed of one piece.

9. A thermal module comprising a base trough according to claim 1 and a radiation absorber plate or a photovoltaic cell arrangement, wherein the radiation absorber plate or the PV cell arrangement is fixed on the plurality of wall portions of the base trough by means of adhesive bonding or mechanical fastening means.

10. The thermal module according to claim 9, wherein the thermal module is a hybrid photovoltaic-thermal module and adapted to generate electric energy.

11. The base trough for a thermal module according to claim 1, wherein the feeding channel and collecting channel each have an inlet port and an outlet port for connecting the feeding channel and the collecting channel to the inlet ports and outlet ports of one or more neighboring thermal modules.

12. The base trough for a thermal module according to claim 1, having a plurality of fastening recesses and/or protrusions for mounting the module on a surface.

13. A method for exchanging thermal energy by operating a thermal module according to claim 9, the method comprising the steps of: a. heating or cooling a heat exchanger medium in a heat exchanger portion of the flow channel of the thermal module; and b. collecting the heat exchanger medium; from the thermal module for reconditioning.

14. Use of a base trough according to claim 1 for extracting energy from sunlight.

15. A system for extracting thermal energy, in particular extracting thermal energy from sunlight, the system comprising: a plurality of thermal modules according to claim 9, wherein each module has a housing comprising a flow adjustment actuator for transporting and/or controlling the flow of the heat exchanger 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; at least one controller for controlling the flow control 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 and/or one or more signal(s) received from the at least one sensor.

16. The system according to claim 15, wherein the flow adjustment actuator is a pump and the pump is operable in reverse such that the thermal module is heated.

17. The base trough for a thermal module as in claim 1 wherein the mean depth of the heat exchanger portion of the fluid channel is smaller than the mean diameter of a cross-section through the feeding channel and smaller than the mean diameter of a cross-section through the collecting channel by a factor of 1.5 to 15.

18. The base trough for a thermal module as in claim 1 wherein the mean depth of the heat exchanger portion of the fluid channel is smaller than the mean diameter of a cross-section through the feeding channel and smaller than the mean diameter of a cross-section through the collecting channel by a factor of 2 to 10.

19. The base trough for a thermal module as in claim 6 wherein the edge of the elongated protrusion is spaced apart from the radiation absorber plate or from the outermost layer of a photovoltaic cell arrangement by 1 to 5 mm.

20. The base trough for a thermal module according to claim 7, wherein the ceramics are selected from the group consisting of clay, terra cotta, zeolite and/or glass, the polymers are selected from the group consisting of PP, PET, PA, ABS, PEEK, PC and/or PMMA, the biomaterials are selected from the group consisting of wood, lignin and/or wool, and the metals are selected from the group consisting of, in particular aluminum and/or copper.

Description

[0117] The following figures show:

[0118] FIG. 1 Perspective view on a base trough according to the invention (from diagonally above);

[0119] FIG. 1A Perspective view on a detail of FIG. 1;

[0120] FIG. 2A Top view on a base trough according to the invention;

[0121] FIG. 2B Lateral view (side extending along the flow path) on a base trough according to the invention;

[0122] FIG. 3 Perspective view on an alternative embodiment of a thermal module;

[0123] FIG. 4 Perspective view on a base trough according to the invention (from diagonally below);

[0124] FIG. 5 Bottom view on a base trough according to the invention;

[0125] FIG. 6 Bottom view on a base trough according to the invention indicating linear cuts AA, BB and CC;

[0126] FIG. 7 Cross-section of linear cut AA through the base trough of FIG. 6;

[0127] FIG. 8 Cross-section of linear cut BB through the base trough of FIG. 6;

[0128] FIG. 9 Cross-section of linear cut CC through the base trough of FIG. 6;

[0129] FIG. 10 Enlarged view on detail D of FIG. 9;

[0130] FIG. 11 Perspective view on a thermal module according to the invention, the base trough and a PV cell arrangement being assembled for the intended use;

[0131] FIG. 12 Schematic depiction of a system for extracting thermal energy from sunlight.

[0132] FIG. 1 shows a perspective view on a base trough according to the invention (from diagonally above). The base trough is for a thermal module and it is configured to be covered by a radiation absorber plate or by the outer-most layer of a photovoltaic (PV) cell arrangement, the said layer facing away from the sun. There is a heat exchanger portion of a flow channel 3 formed, the breadth of which is indicated by the curled bracket. When assembled for the intended use, the absorber plate or PV cell arrangement (not shown) would be lowered onto the heat exchanger portion to seal off the flow channel adjacent, preferably immediately adjacent, to the radiation absorber plate/the outermost layer of the PV cell arrangement, for a heat exchanger medium, preferably a heat extraction medium, to flow through. The base trough 4 comprises a plurality of wall portions 20,20′,20″,20′″ for contacting the said radiation absorber plate or the said outermost layer of the PV cell arrangement in a fluid-tight manner. The trough has a recess for forming a heat exchanger portion of the flow channel 3, a recess or tube for forming a feeding channel 7 and a recess or tube for forming an outlet channel 8. The recess for the heat exchanger portion of the flow channel has an open inlet 21 which communicates with the feeding channel 7 and an open outlet 22 which communicates with the collecting channel 8. The feeding channel and the collecting channel extend along opposed heads of the base trough 4.

[0133] As can be seen from the enlarged view of the transition between inlet tube and heat exchanger portion in FIG. 1A, the mean depth 23 of the heat exchanger portion of the fluid channel is smaller than the mean diameter of a cross-section through the feeding channel and also smaller than the mean diameter of a cross-section through the collecting channel by at least a factor 1.2, preferably by a factor 1.5 to 15, more preferably by a factor 2 to 10.

[0134] In the shown embodiment, the heat exchanger portion 3 of the flow channel has a plurality of grooves 5,5′,5″ for the heat extraction medium to flow through, wherein the grooves 5,5′,5″ are arranged in parallel to each other; and are arranged such that neighboring grooves are separated from one another in a longitudinal direction by elongated protrusions 6,6′,6″.

[0135] FIG. 2A shows a top view on a base trough according to the invention. It can again be seen that the heat exchanger portion 3 has an evenly corrugated surface, in the present case a rectangular plate having around 60 linear grooves extending between the head ends 7 and 8. FIG. 2B shows a lateral view (side extending along the flow path) on a base trough according to the invention. The diameter of the feeding channel's and collecting channel's inlet/outlet have a diameter of 17 mm each in the shown embodiment.

[0136] FIG. 3 shows a perspective view on an alternative embodiment of a thermal module, wherein the feeding channel 7 is provided in curved shape in order to accommodate a junction box with a separating diode and cables (MC4-EU standard), which allows to control operation of individual modules of a system independently of each other. As can be seen from the embodiment, the feeding and/or collecting channel(s) 7,8 need not be of a linear shape.

[0137] FIG. 4 shows a perspective view on a base trough according to the invention (from diagonally below). The base trough 4 for a thermal module 1 has a plurality of struts 24 for providing stability and fastening recesses 25,26 and/or protrusions 27 for mounting the module on a surface, in particular on a roof or a wall of a building. The same structures for stability and ease of mounting are visible in FIG. 5, which shows a bottom view on a base trough according to the invention.

[0138] FIG. 6 again shows a bottom view on a base trough according to the invention indicating linear cuts AA, BB and CC.

[0139] FIG. 7 shows a cross-section of linear cut AA through the base trough of FIG. 6. As can be seen from this Figure, the head wall portions have supports shoulder sections where the radiation absorber plate or outermost layer of the PV cell arrangement rests in an assembled state. In the present case, the base trough even includes circumferential shoulder sections such that the rectangular cover is supported on each side.

[0140] FIG. 8 shows a cross-section of linear cut BB through the base trough of FIG. 6 and FIG. 9 shows a cross-section of linear cut CC through the base trough of FIG. 6. The lateral shoulder portions as well as the mounting protrusions can be seen from these cross sections. Also, the maximum depth of the heat exchanger portion, which is here indicated as 5 mm, hence more than three times smaller than the feeding channel's and collecting channel's inlet/outlet diameter.

[0141] FIG. 10 shows an enlarged view on detail D of FIG. 9. The cross-section through an individual groove has the shape of a semi-ellipse opening towards the position of the absorber plate/the outermost layer of a PV cell arrangement. The curved arrow implies that in some embodiments, the elongated protrusions 6 of the heat exchanger portion may be spaced apart from the radiation absorber plate (not shown) or from the outermost layer of a PV cell arrangement (not shown), such that the heat exchanger medium is allowed to pass from one groove to the other over an elongated protrusion 6 and to substantially completely wet the surface of the radiation absorber or outermost layer of a PV cell arrangement which is directed towards the flow channel.

[0142] FIG. 11 shows a perspective view on a thermal module according to the invention, the base trough and a PV cell arrangement being assembled for the intended use. In the shown embodiment, the PV cell arrangement is a 2×3 wafer 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, e.g. flow adjustment actuators. The panel pf PV cells may be provided under a glass plate in an aluminum frame.

[0143] FIG. 12 shows a schematic view of a system for extracting thermal energy from sunlight. The system has a plurality of thermal modules according to the invention, which are located on top of a saddle roof of a building. Each module 101,101′ has a housing. The components comprised in the housing (radiation absorber, at least one flow channel for a heat extraction medium, a flow adjustment actuator, receiver connected to the flow adjustment actuator for receiving an output signal 104 of at least one controller 105, and optionally: at least one sensor) are not shown in FIG. 1. A controller 105 for controlling the flow control actuators in the plurality of solar thermal modules is comprised in the system. The controller 105 receives data, which is stored in a memory unit 140 connected to the controller, and which may consist of, e.g. astronomic, climatic or meteorological data. The controller 105 additionally or alternatively receives one or more signals 107,107′ from at least one sensor. The sensor(s) may be comprised in the housing of a module (not shown) or there may be an ambient sensor(s) 114, purposefully placed to detect a parameter which is relevant for an entire region or cluster of the system. The controller 105 is adapted to individually regulate the flow adjustment actuators of the plurality of modules 101,101′ depending on the data received from the memory unit 140, and/or on the signal(s) 107 received from a sensor comprised in the housing of a module, and/or on the signal(s) 107′ received from an ambient sensor 114. In order to regulate the flow adjustment actuators of the plurality of modules 101,101′, the controller 105 sends out an output signal 104 to the receivers of the modules 101,101′.