COGENERATION SYSTEM AND METHOD FOR THE COMBINED HEAT AND POWER GENERATION FROM SOLAR THERMAL ENERGY

Abstract

Cogeneration system for thermal and electric energy production from thermosolar energy, having a solar field connected to a power island, a piping system through which a heat transfer fluid flows is provided. The piping system has pipe collectors and a thermal insulating system. The system has at least a photovoltaic panel placed over the piping system, connected to at least a battery further connected to heating device placed at the pipe collectors configured to receive power from the battery and to heat the heat transfer fluid to a temperature suitable for the operation of the power island during periods of low or non-existent solar radiation. A cogeneration method is also provided, which has harvesting solar energy by photovoltaic panels, storing the energy in batteries and heating the heat transfer fluid by the heating device.

Claims

1. Cogeneration system for thermal and electric energy production from thermosolar energy, comprising a solar field connected to a power island by means of a piping system through which a heat transfer fluid flows, the piping system comprising a plurality of pipe collectors through which the heat transfer fluid flows, and a thermal insulating system covering the pipe collectors, said cogeneration system further comprising at least a photovoltaic panel placed over at least a section of the piping system, fixed to the thermal insulating system, and connected to at least a power storage battery, which is further connected to heating means placed at the pipe collectors configured to receive electric power from the power storage battery and to heat the heat transfer fluid to a temperature suitable for the operation of the power island during periods of low or non-existent solar radiation.

2. Cogeneration system for thermal and electric energy production from thermosolar energy, according to claim 1, wherein the heating means comprises an electric tracing system wound around at least a section of the pipe collectors.

3. Cogeneration system for thermal and electric energy production from thermosolar energy, according to claim 1, wherein the heating means comprises immersion heaters arranged on at least a section of the pipe collectors.

4. Cogeneration system for thermal and electric energy production from thermosolar energy, according to claim 1, wherein the thermal insulating system comprises an insulating material, a cladding system covering the insulating material, and a support structure supporting the insulating material and the cladding system, comprising in turn a plurality of spacer rings placed under the cladding system, and wherein the photovoltaic panels are fixed to the thermal insulating system by means of fixing structures placed over the cladding system and fixed to the spacer rings.

5. Cogeneration system for thermal and electric energy production from thermosolar energy, according to claim 1, wherein the piping system further comprises at least a vessel and/or a tank, and a thermal insulating system covering the vessel and/or tank, and wherein at least a photovoltaic panel is placed over the thermal insulating system covering the vessel and/or tank and connected to at least a power storage battery, which is further connected to heating means placed at the pipe collectors, vessels and/or tanks, configured to receive electric power from the power storage battery and to heat the heat transfer fluid to a temperature suitable for the operation of the power island during periods of low or non-existent solar radiation.

6. Cogeneration system for thermal and electric energy production from thermosolar energy, according to claim 1, wherein the photovoltaic panels are flexible.

7. Cogeneration system for thermal and electric energy production from thermosolar energy, according to claim 1, wherein the photovoltaic panels are rigid.

8. Cogeneration method for thermal and electric energy production from thermosolar energy, which comprises harvesting solar energy by means of a solar field and transferring said energy to a power island by means of a piping system through which a heat transfer fluid flows, said cogeneration method further comprising harvesting solar energy by means of at least a photovoltaic panel placed over at least a section of the piping system, storing the energy in at least a power storage battery connected to the photovoltaic panel heating the heat transfer fluid of the piping system by means of heating means placed at the piping system, said heating means connected to the photovoltaic panel, and configured to receive electric power from the power storage battery and to heat the heat transfer fluid to a temperature suitable for the operation of the power island during periods of low or non existent solar radiation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Next, in order to facilitate the comprehension of the invention, in an illustrative rather than limitative manner an embodiment of the invention with reference to a series of figures shall be made below.

[0032] FIG. 1 is a schematic perspective view of a section of the present invention showing a section of the piping system and a plurality of photovoltaic panels fixed to it. Part of the insulating system has been removed to show clearly the pipe collector.

[0033] FIG. 2 is a front view of the section of the piping system of FIG. 1 showing the fixing structures that fix the photovoltaic panels to the insulating system.

[0034] These figures refer to the following set of elements:

[0035] 1. pipe collectors

[0036] 2. thermal insulating system

[0037] 3. photovoltaic panels

[0038] 4. power storage battery

[0039] 5. heating means

[0040] 6. heat transfer fluid

[0041] 7. insulating material

[0042] 8. cladding system

[0043] 9. spacer rings

[0044] 10. fixing structures

[0045] 11. electric wiring system

DETAILED DESCRIPTION OF THE INVENTION

[0046] An object of the present invention is a cogeneration system for thermal and electric energy production from thermosolar energy.

[0047] This cogeneration system has a solar field connected to a power island by means of a piping system through which a heat transfer fluid (HTF) 6 flows.

[0048] As shown in the figures, the piping system comprises a plurality of pipe collectors 1 through which the heat transfer fluid 6 flows, a thermal insulating system 2 which covers the pipe collectors 1, and it may comprise additionally different vessels and/or tanks for storing the heat transfer fluid 6 when necessary.

[0049] Further, the cogeneration system of the present invention comprises one or more photovoltaic panels 3 placed over at least a section of the piping system, and fixed to the thermal insulating system 2. The photovoltaic panels 3 are connected to at least a power storage battery 4, which is further connected to heating means 5 placed at the pipe collectors 1. These heating means 5 are configured to receive electric power from the power storage battery 4 and to heat the heat transfer fluid 6 to a temperature suitable for the operation of the power island during periods of low or non-existent solar radiation.

[0050] Although the system can work with only a photovoltaic panel 3, a preferred embodiment of the invention comprises a plurality of photovoltaic panels 3, as disclosed in FIG. 1, which cover the entire surface of the piping system.

[0051] According to different particular embodiments of the invention, the photovoltaic panels 3 may be rigid or flexible.

[0052] For certain embodiments in which the piping system further has one or more vessels and/or tanks for storing the heat transfer fluid 6, the thermal insulating system 2 will cover said vessels and/or tanks, and according to the present invention, one or more photovoltaic panels 3 will be placed covering the vessels and/or tanks. These photovoltaic panels 3 will also be connected to heating means 5 placed at the pipe collectors 1, vessels and/or tanks, which are configured to receive electric power from the power storage battery 4 and to heat the heat transfer fluid 6 to a temperature suitable for the operation of the power island during periods of low or non-existent solar radiation.

[0053] According to different embodiments of the invention, the heating means 5 may be selected between an electric tracing system wound around at least a section of the pipe collectors 1, and immersion heaters that are immersed inside at least a section of the pipe collectors 1. FIG. 1 shows an electric tracing system wound around a section of the pipe collector 1.

[0054] The electric tracing system will wrap the outer surface of the pipe collectors 1, vessels and/or tanks that transport the heat thermal fluid 6 up to the power island, providing the suitable temperature for the operation of said power island, typically 300-600 C. In case of immersion heaters, they will be placed partially inside the pipe collectors 1, vessels and/or tanks to heat directly the heat thermal fluid 6. In both cases, the working hours of the thermosolar plant will increase, until batteries are completely discharged.

[0055] So, the photovoltaic panels 3 harvest solar energy during strong solar radiation, and it is transported through an electric wiring system 11 to the storage power storage batteries 4 located on lower part of the piping system. Therefore, during strong solar radiation periods the batteries 4 will be charged by the photovoltaic panels 3 and during periods of low or non-existent solar radiation, they will be activated to power the electric tracing system and/or immersion heaters previously installed around or inside the containment elements of the heat transfer fluid, e.g. pipe collectors 1, vessels and/or tanks.

[0056] In accordance with a preferred embodiment, the thermal insulating system 2 comprises an insulating material 7, a metal cladding system 8 that covers the insulating material 7, and a support structure supporting the insulating material and the cladding system. The support structure comprises in turn a plurality of spacer rings 9 placed under the cladding system 8. According to this preferred embodiment, the photovoltaic panels 3 are fixed to the thermal insulating system 2 by means of fixing structures 10 placed over the cladding system 8 and further fixed to the spacer rings 9. The rigid or flexible photovoltaic panels 3 are lightweight, less than 4 kg/m.sup.2, and so they can be supported on small fixing structures 10 directly located on the cladding system 8 and fixed to the spacer rings 9. Due to this low weight of the photovoltaic panels 3, the existing metal cladding system 8 and spacer rings 9 of the existing piping systems could admit this little overload with minimum resizing and alterations, without additional complex structures made of heavy steel and additional concrete bedplates that are usually needed to support conventional panels.

[0057] In this way, the solar radiation, which previously fell on the metal cladding of the piping system and was not actually used, now is harvested by the photovoltaic panels 3 and is stored to be used during periods of low or non-existent solar radiation. Additionally these photovoltaic panels 3 protect the metal cladding 8 from the solar radiation, as shown in FIG. 1, lengthening the life thereof.

[0058] Another object of the invention is a cogeneration method for thermal and electric energy production from thermosolar energy, as disclosed in claim 9 of the present application.

[0059] This cogeneration method provides both thermal and electric energy from thermosolar energy, and it comprises the steps of harvesting solar energy by means of a solar field and transferring said energy to a power island by means of a piping system through which a heat transfer 6 fluid flows.

[0060] Further, the method comprises the steps of harvesting solar energy by means of one or more photovoltaic panels 3 placed over at least a section of the piping system, storing the energy in at least a power storage battery 4 which is connected to the photovoltaic panels 3, and heating thus the heat transfer fluid 6 of the piping system by means of heating means 5 placed at the piping system. These heating means 5 are connected to the photovoltaic panels 3, and they are configured to receive electric power from the power storage battery 4 and to heat the heat transfer fluid 6 to a temperature suitable for the operation of the power island during periods of low or non existent solar radiation.

[0061] Once the invention has been clearly described, it is hereby noted that the particular embodiments described above can be the subject of detail modifications as long as they do not alter the fundamental principle and the essence of the invention.