WIND TURBINE WASTE HEAT RECOVERY SYSTEM

Abstract

A waste heat recovery system of a wind turbine is provided. A wind turbine is disclosed, including an electrical installation to transform wind energy into electrical energy, whereby the electrical installation produces waste heat. The wind turbine includes a waste heat recovery system to transform at least a part of the waste heat into electrical energy.

Claims

1. A wind turbine comprising: an electrical installation to transform wind energy into electrical energy, whereby the electrical installation produces waste heat; and a waste heat recovery system to transform at least a part of the waste heat into electrical energy.

2. The wind turbine according to claim 1, comprising a cooling system with a cooling circuit to cool the electrical installation that produces waste heat, whereby the waste heat recovery system is connected to the cooling circuit of the wind turbine in a way that thermal energy is transferred from the cooling circuit to the waste heat recovery system.

3. The wind turbine according to claim 2, wherein the waste heat recovery system comprises: a fluid circuit to transport thermal energy, wherein the thermal energy of the cooling circuit of the wind turbine is transferred to a fluid in the fluid circuit of the waste heat recovery system; a turbine to expand the fluid in the fluid circuit of the waste heat recovery system, and to transform thermal energy of the fluid into rotational energy of the turbine; and a waste heat recovery generator to transform the rotational energy of the turbine into electrical energy.

4. The wind turbine according to claim 3, wherein the fluid circuit of the waste heat recovery system comprises a fluid, and a boiling temperature of the fluid is below 100° C.

5. The wind turbine according to claim 4, wherein the boiling temperature of the fluid is below 80° C. and above 20° C.

6. The wind turbine according to claim 3, wherein the fluid is an organic liquid, and a process to transform the thermal energy into electrical energy is employing an Organic Rankine Cycle.

7. The wind turbine according to claim 6, wherein the waste heat recovery system comprises an evaporator to evaporate the fluid by the thermal energy transferred from the cooling circuit of the wind turbine.

8. The wind turbine according to claim 6, wherein the waste heat recovery system comprises a condenser to condense the fluid and to extract thermal energy from the fluid in the fluid circuit.

9. The wind turbine according to claim 6, wherein the waste heat recovery system comprises a pump to move the fluid in the fluid circuit of the waste heat recovery system.

10. The wind turbine according to claim 3, wherein the fluid is carbon dioxide, and a process to transform the thermal energy into electrical energy is employing a Carbon Transcritical Power Cycle.

11. The wind turbine according to claim 10, wherein the waste heat recovery system comprises a first heat exchanger that connects the cooling circuit of the wind turbine and the fluid circuit of the waste heat recovery system to transfer thermal energy from the cooling system to the fluid circuit.

12. The wind turbine according to claim 11, wherein the waste heat recovery system comprises a second heat exchanger, to transfer heat from the fluid after an exit of the turbine in a flow direction of the fluid, to the fluid before an entrance of the first heat exchanger, to re-use the thermal energy present in the fluid circuit.

13. The wind turbine according to claim 2, wherein the wind turbine comprises a rotor and a wind turbine electrical generator that is connected to the rotor in a way that a rotational energy of the rotor is transferred to the electrical generator to transform wind energy into electrical energy, and the cooling circuit of the wind turbine cools the wind turbine electrical generator.

14. The wind turbine according to claim 1, wherein the wind turbine comprises a nacelle, and the waste heat recovery system is located in the nacelle.

15. The wind turbine according to claim 14, wherein the nacelle comprises an housing, and thermal energy of a condenser of the waste heat recovery system is transferred to environmental air by a cooler that is connected to an outside of the housing of the nacelle.

Description

BRIEF DESCRIPTION

[0064] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0065] FIG. 1 shows a wind turbine comprising a waste heat recovery system;

[0066] FIG. 2 shows a detailed embodiment of a wind turbine with a waste heat recovery system;

[0067] FIG. 3 shows a detailed view of the waste heat recovery system; and

[0068] FIG. 4 shows an alternative embodiment of a waste heat recovery system.

DETAILED DESCRIPTION

[0069] FIG. 1 shows a wind turbine comprising a waste heat recovery system.

[0070] FIG. 1 shows a wind turbine comprising a waste heat recovery system 11.

[0071] A wind turbine transforms rotational energy into electrical energy. Therefore, a shaft 4 is connected to an electrical generator 5. The electrical energy from the generator 5 is transformed in a converter or transformer 6 to achieve the electrical energy output 7 that is needed.

[0072] The electrical installations 5, 6 are cooled by a cooling system 8, using a liquid or air, for example. The cooling system is connected to the waste heat recovery system 11 that transforms the thermal energy of the cooling system 8 into electrical energy 14.

[0073] Thus, the waste heat of the electrical installations 5, 6 is used to generate additional electrical energy.

[0074] FIG. 2 shows a detailed embodiment of a wind turbine with a waste heat recovery system.

[0075] The wind turbine 1 comprises a hub 2 and a nacelle 3. A rotor blade is connected to the hub 2 and the wind interacts with the rotor blade to cause a rotation of the hub 2 in respect to the nacelle 3. The rotation of the hub 2 is transferred by a shaft 4 to an electrical generator 5.

[0076] The electrical energy from the generator 5 is transferred to other electrical installations 6 to transform the electrical energy into the output power 7 needed. The electrical installations 5, 6 are cooled by a cooling circuit 8.

[0077] The cooling circuit 8 is connected by a heat exchanger 9 to the fluid circuit 10 of the waste heat recovery system 11. The waste heat recovery system 11 transforms the thermal energy transferred from the cooling system 8 into electrical energy 14.

[0078] A part of the remaining waste heat is transferred by a cooling circuit 12 to a cooler 13 that is arranged in a way that it can be cooled by environmental air in the vicinity of the nacelle 3 or by sea water.

[0079] FIG. 3 shows a detailed view of the waste heat recovery system.

[0080] The waste heat recovery system comprises a fluid circuit 10. The fluid in the fluid circuit 10 is carbon dioxide, for example.

[0081] A pump 15 moves the fluid in the fluid circuit 10. Waste heat is transferred to the waste heat recovery system by a cooling circuit 8 and a heat exchanger 9. The fluid in the fluid circuit 10 is heated by the thermal energy transferred from the cooling circuit 8.

[0082] The waste heat evaporates the fluid in the fluid circuit 10. The steam created in the heat exchanger 9 is expanded in a turbine 16. The thermal energy of the steam in the fluid circuit 10 is transformed into rotational energy of the turbine 16.

[0083] The rotational energy of the turbine 16 is transformed into electrical energy by the generator 17 of the waste heat recovery system.

[0084] The expanded steam of the cooling circuit 10 is condensed in a condenser 13. Thus, a part of the remaining thermal energy of the fluid in the fluid circuit 10 is removed by cooling the fluid.

[0085] The fluid then flows through the pump 15 towards the evaporator 9.

[0086] An additional internal heat exchanger 18 is present in the fluid circuit 10 to transfer a part of the remaining thermal energy of the steam after the expanded steam leaves the turbine 16 to the condensed fluid before it enters the evaporator 9.

[0087] The condenser 13 can be cooled by air, by sea water, or by an additional cooling circuit.

[0088] FIG. 4 shows an alternative embodiment of a waste heat recovery system.

[0089] The waste heat recovery system comprises a fluid circuit 10. The fluid and the fluid circuit 10 is an organic liquid and the waste heat recovery system is using an Organic Rankine Cycle.

[0090] The pump 15 is present in the fluid circuit 10 to move the liquid in the fluid circuit. The fluid enters an evaporator 19, the waste heat is transferred by a cooling circuit 8 to the evaporator and is used to evaporate the liquid.

[0091] The steam of the organic liquid is expanded in a turbine 16. The thermal energy of the fluid in the fluid circuit 10 is transformed into rotational energy of the turbine 16 and into electrical energy 14 by a generator connected to the turbine 16.

[0092] The expanded steam of the fluid is condensed in a condenser 20. A part of the remaining thermal energy is removed from the fluid. The condenser 20 can be cooled by ambient air or by an additional cooling circuit removing the thermal energy 21.

[0093] After being condensed in the condenser 20, the fluid comes back to the pump 15 and returns to the evaporator 19.

[0094] The illustration in the drawings is in schematic form. It is noted that in different figures, similar or identical elements are provided with the same reference signs.

[0095] Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.

[0096] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.