Advanced aircraft power generation applications require uninterrupted, reliable electric power availability during the full flight envelope to drive various electrical systems of the aircraft. Conventionally, the aircraft utilizes an electric power generator coupled to the main engines of the aircraft and an auxiliary power unit (APU) to generate the electrical power. These conventional power generation methods, however, include numerous large and complex rotational parts that increase the weight of the aircraft and may induce electrical noise, such as electromagnetic magnetic interference (EMI). As aircraft electrical systems become more complex and provide more electrical features, the demand for lightweight compact energy systems to generate additional power increases.
In at least one embodiment, an energy recovery and regeneration system comprises at least one pyroelectric energy recovery module (ERM), a coolant line, a valve and an energy storage module. The at least one pyroelectric ERM generates a voltage in response to realizing a temperature change. The coolant line includes a first end in fluid communication with a coolant source to receive a coolant and a second end disposed adjacent the at least one pyroelectric ERM to deliver the coolant thereto. The valve is interposed between the coolant source and the at least one pyroelectric ERM. The valve modulates the coolant delivered to the at least one pyroelectric ERM to generate the temperate change. The energy storage module is in electrical communication with the pyroelectric ERM to store the voltage generated by the at least one pyroelectric ERM.
In another embodiment, an energy recovery and regeneration system comprises at least one thermoelectric ERM that includes a first surface and a second surface. The thermoelectric ERM is configured to generate a voltage in response to realizing a temperature differential between the first surface and the second surface. The energy recovery and regeneration system further comprises at least one coolant line including a first end and a second end. The first end is in fluid communication with a coolant source to receive a coolant. The second end is disposed adjacent the second surface of the at least one thermoelectric ERM to deliver the coolant thereto such that the second surface has a temperature less than the first surface. An electronic device is in electrical communication with the at least one thermoelectric ERM, and operates in response to the voltage generated by the thermoelectric ERM.
In still another embodiment, an energy recovery and regeneration system comprises at least one piezoelectric ERM configured to generate a voltage in response to realizing a physical force. At least one coupling member includes a first linking end and a second linking end to deliver the physical force to the at least one piezoelectric ERM. The first linking end is formed at the at least one coupling member and the second linking end is formed against a vibration source. An energy storage module is in electrical communication with the piezoelectric ERM to store the voltage generated by the at least one piezoelectric ERM.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
The APU 110 may provide power to start the main turbine engines of the aircraft. For example, the main turbine engines must be accelerated to a high rotational speed in order to provide sufficient air compression for self-sustaining operation. The APU 110 may be used to provide electrical power to one or more accessory systems, such as electronic dashboard electronics, cabin air fans, cabin lighting, lavatory/galley power, etc., while the main engines are shut down. The APU 110 may also be connected to a hydraulic pump, allowing crews to operate hydraulic equipment (such as flight controls or flaps) prior to the main engine(s) start. As previously mentioned, however, the APU 110 requires a variety of moveable and rotational parts.
In at least one embodiment, the aircraft's rear bulkhead 100 contains an energy recovery and regeneration system 102 configured to harness/recover energy existing in the aircraft. The recovered energy may be stored and/or supplied to various electrical sub-systems to increase the energy efficiency of the aircraft. Although at least one embodiment described going forward illustrates the energy recovery and regeneration system 102 contained in the rear bulkhead 100, the location of the energy recovery and regeneration system 102 is not limited thereto. Accordingly, it is appreciated that the energy recovery and regeneration system 102 may be formed at one or more alternative locations of the aircraft.
Referring again to
The pyroelectric energy recovery and regeneration system 102 includes one or more pyroelectric energy recovery modules (ERMs) 126, a coolant line 128, a fast-acting valve 130, and an energy storage module 132. The pyroelectric ERMs 126 generate a temporary voltage when realizing a temperature change (i.e., when being heated or cooled), as discussed in greater detail below. The pyroelectric ERMs 126 may be disposed against the heated external surface of the APU exhaust duct 122, for example. According to the embodiment illustrated in
As mentioned above, a single temperature change realized by the pyroelectric ERMs 126 generates a temporary voltage. To maintain a continuous voltage output, the pyroelectric ERMs 126 must realize a continuous temperature change, i.e., the pyroelectric ERMs 126 must be heated and cooled in a continuous and alternating manner. Accordingly, the fast-acting valve 130 may be interposed between the air inlet 112 and the pyroelectric ERMs 126 to open and/or close the air delivery path to the pyroelectric ERMs 126. The fast-acting valve 130 may be controlled by, for example, a microprocessor. The continuous opening and closing of the valve 130 causes the cool inlet air to be modulated across the pyroelectric ERMs 126. The continuous modulation of cool air generates a continuous alternating temperature differential across the pyroelectric ERMs 126 to maintain a continuous output voltage. Accordingly, the inlet air that is provided to the APU compressor 120 may be leveraged and harnessed to generate additional energy that may be stored and/or utilized by one or more sub-systems of the aircraft.
Although cool inlet air is used as the coolant supplied to the pyroelectric ERMs 126, other coolants may be used. Referring to
Turning to
Referring now to
The pyroelectric material of the ERM semiconductor element 164 is configured to generate voltage when the pyroelectric material is subjected to alternating heating and cooling. The heat absorbed by the pyroelectric material then changes the positions of the atoms in the material's crystal lattice structure. This leads to a polarization change which in turn, causes a voltage rise across the ERM semiconductor element. Typical energy densities for pyroelectric devices are quoted in the range of approximately 5 Watts per kilogram (W/kg) to approximately 30 W/kg) using, for example, Poly(Vinylidene Fluoride-TriFluoro-Ethylene (P(VDF-TrFE)). Accordingly, the pyroelectric ERM 164 regenerates energy that is typically “unused” or lost from the system. Thus, energy may be recaptured and regenerated without any large or complex rotating and/or moving parts.
The plurality of semiconductor elements 164 includes at least one P-type semiconductor element (P) and at least one N-type semiconductor element (N). The P-type element (P) is formed by doping a semiconductor element with a P-type material such as, for example, phosphorus (P). The N-type element N is formed by doping a semiconductor element with a N-type material such as, for example, boron (B). Further, the semiconductor elements 164 may have a temperature threshold (TTH). In at least one embodiment, the ERM semiconductor elements 164 are formed as thin strips that may be formed against a heated surface, such as the APU exhaust duct 122. The strips may be thin enough such that they conform to the shape of the heated surface. Accordingly, a maximum surface area of the ERM may be disposed against the heat source to receive a maximum amount of heat, thereby maximizing the voltage generated by the pyroelectric ERM 126.
The first thermally conductive surface 166 may be cooled below (TTH), while the second thermally conductive surface may be heated above (TTH) 166 (See
Based on the energy recovery and regeneration system 102 discussed above, a method of recovery and regenerating energy may be achieved. More specifically, a coolant may be provided to a first surface of the pyroelectric ERMs 126, which generate a voltage in response to realizing a temperature change as discussed above. The coolant may be modulated, for example by continuously opening and closing a fast-acting valve 130, such that the pyroelectric ERMs 126 realize a continuous temperature change, thereby generating a continuous voltage. The voltage output by the pyroelectric ERMs 126 may then be delivered to an energy storage module 132 to be stored, or to an electrical system to power one or more electronic devices.
Turning now to
Unlike the pyroelectric ERMs 126, a continuous alternating temperature change is not necessary to maintain an output voltage. The coolant lines 176 include a first end that is in fluid communication with an inlet 180 of the SCU 178. The coolant lines 176 may then be formed adjacent a thermally conductive surface of the thermoelectric ERMs 174 to deliver cooler temperature to thereto. The opposite surface of the thermoelectric ERMs 174 may be heated. For example, the opposite surface of the thermoelectric ERMs 174 may be disposed against the heated exterior surface of the APU exhaust duct 122. Accordingly, the thermoelectric ERMs 174 realize a temperature change, thereby generating an output voltage (VOUT) that may be stored by an energy storage module 132 as discussed above. The coolant lines 176 may be returned to the SCU 178, which re-cools the coolant and returns cooled coolant back to the thermoelectric ERMs 174 to maintain the temperature difference. Although coolant lines 176 and an SCU 178 is described with respect to the thermoelectric energy recovery and regeneration system 102′, it is appreciated that the bleed air line 124 and valve 130 as discussed above may be used to provide cool air to the thermoelectric ERMs 174, and vice versa. It is also appreciated that combination of the SCU 178, the coolant lines, the bleed air line 124 and the valve 130 may also be used.
Referring now to
Turning to
Based on another embodiment of an energy recovery and regeneration system 102 discussed above, a method of recovery and regenerating energy may be achieved. More specifically, a first thermally conductive surface 200 of the thermoelectric ERMs 174 is heated while a second thermally conductive surface 202 of the thermoelectric ERMs is cooled. Accordingly, a temperature differential between the first and second surfaces 200, 202 is generated, which causes thermoelectric ERMs 174 to generate a voltage as discussed above. The voltage output (VOUT) by the thermoelectric ERMs 174 may then be delivered to an energy storage module 132 to be stored, or to an electrical system to power one or more electronic devices.
Turning now to
In another embodiment, a first linking end of a first coupling member 210 is formed at a first end of the piezoelectric ERM 208, while a first linking end of a second coupling member 210 is formed at an opposite end of the piezoelectric ERM 208. The second linking ends of the first and second coupling members may be formed against a vibration source, such as the exhaust struts 218 for example. As the struts 218 vibrate, the first and second coupling members 210 are forced toward and/or away from each other. The piezoelectric ERM 208 therefore realizes a vibration that that deforms (i.e., pushes or pulls) the piezoelectric material thereby generating the output voltage (see
Referring to
Turning to
Therefore, based on yet another embodiment of an energy recovery and regeneration system 102 as discussed above, a method of recovery and regenerating energy may be achieved. More specifically, a vibration may be delivered to the piezoelectric ERM 208. The vibration may be applied to the piezoelectric ERM, 208 or may be applied to ends of the piezoelectric ERM 208 to deform the piezoelectric material. In response to realizing the vibration and/or deformation, the piezoelectric ERMs 208 generate a voltage as discussed above. The voltage output (VOUT) generated by the piezoelectric ERMs 208 may then be delivered to an energy storage module 132 to be stored, or to an electrical system to power one or more electronic devices.
Accordingly, at least one embodiment described in detail above provides an energy recovery and regeneration system configured to harness/recover energy existing at the aircraft, and convert the energy without any large rotational and/or complex moving parts. The energy recovery and regeneration system includes a ERM that is configured to harness/recapture energy lost by one or more systems of an aircraft, and regenerate the energy which may be stored in an energy storage module and/or used to power one or more electrical sub-systems without the use of large and/or complex moving parts.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.