DE102014010885B4 - Method and device for converting thermal energy into electrical energy - Google Patents

Abstract

Method for converting thermal energy into electrical energy in a circuit (20) having a voltage source (6, 28) and consuming device (7), comprising the following steps: coating at least one insulating dielectric material (3) having a crystalline and a defect concentration structure metallic electrodes (4, 5) for forming at least one metal-insulator-metal stack (43), the metal-insulator-metal stack (43) being connected to the circuit (20) with voltage source (6, 28) and consumer device ( 7), applying / switching a voltage UPE from the voltage source (6, 28) to lower the crystal symmetry by forming a defect concentration gradient in the insulating dielectric material (3), the insulating dielectric material (3) becoming a switchable pyroelectric material, and thus producing pyroelectric phases in the insulating dielectric material (3) having a polarization in the mate 3), coupling high temperature heat fluxes T and low temperature heat fluxes T as introduced thermal energy in a predetermined change by means of a heat exchanger (8) to the generated pyroelectric phases, wherein the metal-insulator-metal stack (43), the voltage source (6, 28), the consumption device (7) and the thermally coupled heat exchanger (8) form a switchable pyroelectric converter (2), and tapping an electric current as electrical energy from the circuit (20) after the mutual thermal coupling of the heat flows as a result of a polarization change of the previously generated pyroelectric phases, characterized in that a pyroelectric material is provided with a defect insulating dielectric material (3) having a centrosymmetric crystal symmetry and a defect concentration at which pyroelectricity is built up by the voltage connection and the is formed voltage switchable beyond a conventional Olsen cycle for pyroelectric material, wherein the conventional Olsen cycle is used for switching the voltages, wherein the conventional Olsen cycle comprises the following steps: In a first step (AB) is an electrode-contacted pyroelectric material of the pyroelectric transducer (2) at a predetermined high voltage by means of a heat exchanger and a high-temperature fluid (10) flowing through the heat exchanger until the polarization curve of a high temperature is reached, • in a second step (BC) an isothermal discharge of the surface charge takes place OPE via a voltage applied to the electrode-contacting pyroelectric material voltage source until a predetermined low voltage U is reached, • in a third step (CD) by means of a heat exchanger flowing through low-temperature fluid (11) a cooling step in the range of the predetermined low voltage Usolange until the polarization curve of a lower temperature is reached, and in a step (DA) closing the cycle, an isothermal charging of the surface charge OPE takes place up to the originally predetermined high voltage U, the area (ABCDA ) is the work done and thus the electrical energy in the conversion of thermal energy into electrical energy, wherein in further development of the conventional Olsen cycle at least the following modified steps are performed: • the original second step (BC) is controlled by a controller (12) so modified to a voltage difference-enlarged step (BF), being switched from the high voltage U out the predetermined low voltage Uunterschreitend down to a minimum voltage U, wherein during the modified second step (BF) stepwise parallel is otherme discharging the surface charge OPE via the applied voltage source (6, 28) until the minimum voltage Uim point (F) is reached, the original third step (CD) is modified to a step (FD) such that by means of the during the modified third step (FD), a cooling step is performed from the range of the minimum voltage U from the point (F) until the polarization curve of the original low temperature Tim point (D) with the surface charge OPE is achieved, whereby by means of the voltage change of Unach Ubei surface reached (ABFDA) by the area (BFDCB) increased work and thus increased electrical energy through the switchable pyroelectric material (3) in the switchable pyroelectric transducer (2) is performed.

Description

The invention relates to a method and a device for converting thermal energy into electrical energy.

Pyroelectric materials respond to temperature changes by providing electrical charges on their surface and thereby with the formation of strong electric fields at voltages up to the megavolt range. Thus, they are predestined for applications that require a conversion of thermal energy into other forms of energy.

In the publication US Pat. No. 4,620,262 A a pyroelectric energy converter element is described in which a conversion of thermal energy into electrical energy is described. It discloses a film stack for use in a pyroelectric energy converter, wherein the films of a copolymer of vinylidene fluoride and trifluoroethylene are in a predetermined ratio, wherein the surfaces of the films are covered on both sides with thin metallic electrodes, wherein the films around a central cylindrical core are spirally wound around the stack in a cylindrical shape.
The transducer elements are suitable for the use of waste heat streams. Applications include the use of low-temperature waste heat in fossil and regenerative power plants. Further applications are in areas of material synthesis in which waste heat is present as an unused form of energy, for example in the metal, chemical and food industries.

Pyroelectric materials are already being used commercially in the field of sensor technology as thermal detectors.
In the publication WO 2009/083 181 A1 For example, a device for detecting thermal radiation with a pyroelectric detector arrangement and a method for producing and using the device are described.

The thermal detectors may be designed, for example, as motion detectors. They can be used to count people entering and leaving buildings.
Further applications relate to non-dispersive infrared sensors for the detection of gas or fire. These are used, for example, in the medical sector, in industry, in automotive engineering, in oil and gas production and in aerospace.

The disadvantages of the stated methods and devices are that the efficiency of the conversion of thermal energy into electrical energy on the basis of the so-called Olsen cycle by the process temperature spread described in the Publication MOHAMMADI, Saber; KHODAYARI, Akram: Pyroelectric Energy Harvesting with Thermodynamic-Based Cycles. In: Smart Materials Research, Vol. 2012, Article ID 160956, p.1-5 , by the lower voltage applied to the pyroelectric material described in the document OLSEN, Randall B.; BRUNO, David A.; BRISCOE, J. Merv: Pyroelectric conversion cycles. In: Journal of Applied Physics, Vol. 58, 1985, no. 12, pp. 4709-4716 , as well as by the irreducible heat capacity and not least by the spontaneous polarization and its temperature dependence (pyroelectric coefficient) is limited.

• • In einem ersten Schritt (A-B) wird ein elektrodenkontaktiertes pyroelektrisches Material des pyroelektrischen Wandlers bei einer vorgegebenen hohen Spannung U_H mittels eines Wärmeübertragers und eines den Wärmeübertrager durchströmenden hochtemperierten Fluids solange aufgeheizt, bis die Polarisationskurve einer hohen Temperatur T_H erreicht ist,
• • in einem zweiten Schritt (B-C) erfolgt eine isotherme Entladung der Oberflächenladung OPE über eine an das elektrodenkontaktierende pyroelektrische Material angelegte Spannungsquelle solange, bis eine vorgegebene niedrige Spannung U_L erreicht ist,
• • in einem dritten Schritt (C-D) erfolgt mittels eines den Wärmeübertrager durchströmenden hochtemperierten Fluids ein Abkühlungsschritt im Bereich der vorgegebenen niedrigen Spannung U_L solange, bis die Polarisationskurve einer niedrigeren Temperatur T_L erreicht ist, und
• • in einem den Kreisprozess schließenden Schritt (D-A) erfolgt eine isotherme Aufladung der Oberflächenladung OPE bis zur ursprünglich vorgegebenen hohen Spannung U_H ,

wobei die Fläche (A-B-C-D-A) 44 in 3a die verrichtete Arbeit und damit die erzeugte elektrische Energie bei der Umwandlung von thermischer Energie in elektrische Energie darstellt.The in the publication OLSEN, Randall B.; BRUNO, David A.; BRISCOE, J. Merv: Pyroelectric conversion cycles. In: Journal of Applied Physics, Vol. 58, 1985, no. 12, pp. 4709-4716 described and in the 3a shown conventional Olsen cycle 25 is described in four steps below:

• In a first step (AB), an electrode-contacted pyroelectric material of the pyroelectric transducer is at a predetermined high voltage U _H by means of a heat exchanger and a high-temperature fluid flowing through the heat exchanger until the polarization curve of a high temperature T _H is reached,
• In a second step (BC) an isothermal discharge of the surface charge OPE takes place via a voltage source applied to the electrode-contacting pyroelectric material until a predetermined low voltage is reached U _L is reached,
• In a third step (CD), a cooling step takes place in the range of the predetermined low voltage by means of a high-temperature fluid flowing through the heat exchanger U _L until the polarization curve of a lower temperature T _L is reached, and
• • In a step (DA) closing the cycle process, an isothermal charging of the surface charge OPE takes place up to the originally specified high voltage U _H .

where the area (ABCDA) 44 in 3a represents the work done and thus the electrical energy generated in the conversion of thermal energy into electrical energy.

In presently used thermal detection systems based on pyroelectric materials, a polarization change is induced by an incident infrared radiation in a pyroelectric crystal, whereby a voltage is applied to the surfaces of the crystal by means of electrodes can be detected. To acquire the signal, downstream amplifier electronics are required. As a matter of principle, such amplifier electronics also amplify the signal background, which leads to an increasingly poorer signal in relation to the signal background ratio, especially in the case of weak signals.

The invention has for its object to provide a method and apparatus for converting thermal energy into electrical energy, which are designed so that the efficiency of the conversion of thermal energy into electrical energy is increased. In addition, the work done is to be increased on the basis of the conventional Olsen cycle and the signal to signal background ratio improved.

• - Beschichten mindestens eines isolierenden dielektrischen Materials mit einer kristallinen und eine Defektkonzentration aufweisenden Struktur mit metallischen Elektroden zur Ausbildung mindestens eines Metall-Isolator-Metall-Stapels, wobei der Metall-Isolator-Metall-Stapel zu dem Stromkreis mit Spannungsquelle und Verbrauchseinrichtung gehört,
• - Anlegen/Schalten einer Spannung UPE aus der Spannungsquelle zur Erniedrigung der Kristallsymmetrie durch Ausbildung eines Defektkonzentrationsgradienten im isolierenden dielektrischen Material, wobei das isolierende dielektrische Material zu einem schaltbaren pyroelektrischen Material wird, und damit
• - Erzeugen von pyroelektrischen Phasen im isolierenden dielektrischen Material, die eine Polarisation im Material aufweisen,
• - Ankoppeln von Wärmeströmen hoher Temperatur T_H und Wärmeströmen niedriger Temperatur T_L als eingebrachte thermische Energie im vorgegeben Wechsel mittels eines Wärmeübertragers an die erzeugten pyroelektrischen Phasen, wobei der Metall-Isolator-Metall-Stapel, die Spannungsquelle, der Verbrauchseinrichtung und der thermisch ankoppelbare Wärmeübertrager einen schaltbaren pyroelektrischen Wandler bilden, und
• - Abgreifen eines elektrischen Stromes als elektrische Energie aus dem Stromkreis nach dem wechselseitigen thermischen Ankoppeln der Wärmeströme als Folge einer Polarisationsänderung der vorher erzeugten pyroelektrischen Phasen.

The object of the invention is solved by the features of claims 1 and 9.
The method for converting thermal energy into electrical energy in a circuit with voltage source and consumer device, according to claim 1, the following steps:

• Coating at least one insulating dielectric material having a crystalline and a defect concentration structure with metallic electrodes to form at least one metal-insulator-metal stack, the metal-insulator-metal stack belonging to the circuit comprising the voltage source and the consumable device,
• Applying a voltage UPE from the voltage source to lower the crystal symmetry by forming a defect concentration gradient in the insulating dielectric material, wherein the insulating dielectric material becomes a switchable pyroelectric material, and thus
• Generating pyroelectric phases in the insulating dielectric material having a polarization in the material,
• - Coupling of high temperature heat flows T _H and low temperature heat flows T _L as introduced thermal energy in the predetermined change by means of a heat exchanger to the generated pyroelectric phases, wherein the metal-insulator-metal stack, the voltage source, the consumption device and the thermally coupled heat exchanger form a switchable pyroelectric converter, and
• - Picking up an electric current as electrical energy from the circuit after the mutual thermal coupling of the heat flows as a result of a polarization change of the previously generated pyroelectric phases.

The intrinsic defect concentration present in the insulating dielectric material can be increased relative to room temperature 20 ° C. and normal pressure by means of a treatment at higher temperature and / or under reduced pressure or by ion bombardment.

In this case, a pyroelectric material provided with a defect, insulating dielectric material having a preferably centrosymmetric crystal symmetry is used, on which by connecting a pyroelectricity is built up and which is formed over a conventional Olsen cycle for pyroelectric material out voltage switchable.

• • In einem ersten Schritt (A-B) wird ein elektrodenkontaktiertes pyroelektrisches Material des pyroelektrischen Wandlers bei einer vorgegebenen hohen Spannung U_H mittels eines Wärmeübertragers und eines den Wärmeübertrager durchströmenden hochtemperierten Fluids solange aufgeheizt, bis die Polarisationskurve einer hohen Temperatur T_H erreicht ist,
• • in einem zweiten Schritt (B-C) erfolgt eine isotherme Entladung der Oberflächenladung OPE über eine an das elektrodenkontaktierende pyroelektrische Material angelegte Spannungsquelle solange, bis eine vorgegebene niedrige Spannung U_L erreicht ist,
• • in einem dritten Schritt (C-D) erfolgt mittels eines den Wärmeübertrager durchströmenden niedrigtemperierten Fluids ein Abkühlungsschritt im Bereich der vorgegebenen niedrigen Spannung U_L solange, bis die Polarisationskurve einer niedrigeren Temperatur T_L erreicht ist, und
• • in einem den Kreisprozess schließenden Schritt (D-A) erfolgt eine isotherme Aufladung der Oberflächenladung OPE bis zur ursprünglich vorgegebenen hohen Spannung U_H ,

wobei die Fläche (A-B-C-D-A) die verrichtete Arbeit und damit die elektrische Energie bei der Umwandlung von thermischer Energie in elektrische Energie darstellt,
wobei in Weiterentwicklung des Olsen-Zyklus zumindest folgende modifizierte Schritte durchgeführt werden:

• • der ursprüngliche zweite Schritt (B-C) wird durch eine Steuer-/Regeleinrichtung derart zu einem spannungsdifferenzvergrößerten Schritt (B-F) modifiziert, wobei die hohe Spannung U_H die vorgegebene niedrige Spannung U_L unterschreitend bis auf eine Mindestspannung U_L* verringert geschaltet wird, wobei während des modifizierten zweiten Schrittes (B-F) schrittparallel eine isotherme Entladung der Oberflächenladung OPE über die angelegte Spannungsquelle solange durchgeführt wird, bis die Mindestspannung U_L* im Punkt (F) erreicht wird,
• • der ursprüngliche dritte Schritt (C-D) wird derart zu einem Schritt (F-D) modifiziert, wobei mittels des den Wärmeübertrager durchströmenden niedrigtemperierten Fluids während des modifizierten dritten Schrittes (F-D) ein Abkühlungsschritt aus dem Bereich der Mindestspannung U_L* vom Punkt (F) aus solange erfolgt, bis die Polarisationskurve der ursprünglichen niedrigen Temperatur T_L im Punkt (D) der Oberflächenladung OPE erreicht ist,

wodurch mittels der Spannungsänderung von U_H nach U_L* bei erreichter Fläche (A-B-F-D-A) eine um die Fläche (B-F-D-C-B) erhöhte Arbeit und damit erhöhte elektrische Energie durch das schaltbare pyroelektrische Material im schaltbaren pyroelektrischen Wandler verrichtet wird.For switching the voltages, a conventional Olsen cycle is used, the conventional Olsen cycle comprising the following steps:

• In a first step (AB), an electrode-contacted pyroelectric material of the pyroelectric transducer is at a predetermined high voltage U _H by means of a heat exchanger and a high-temperature fluid flowing through the heat exchanger until the polarization curve of a high temperature T _H is reached,
• In a second step (BC) an isothermal discharge of the surface charge OPE takes place via a voltage source applied to the electrode-contacting pyroelectric material until a predetermined low voltage is reached U _L is reached,
• In a third step (CD), a cooling step takes place in the range of the predetermined low voltage by means of a low-temperature fluid flowing through the heat exchanger U _L until the polarization curve of a lower temperature T _L is reached, and
• • In a step (DA) closing the cycle process, an isothermal charging of the surface charge OPE takes place up to the originally specified high voltage U _H .

wherein the area (ABCDA) represents the work done and thus the electrical energy in the conversion of thermal energy into electrical energy,
wherein in further development of the Olsen cycle at least the following modified steps are carried out:

• The original second step (BC) is modified by a controller in such a way to a voltage difference enlarged step (BF), wherein the high voltage U _H the predetermined low voltage U _L below a minimum voltage U _L * is switched off, while during the modified second step (BF) is carried out step-by-step an isothermal discharge of the surface charge OPE via the applied voltage source until the minimum voltage U _L * reached in point (F),
• The original third step (CD) is modified in such a way to a step (FD), wherein by means of the low-temperature fluid flowing through the heat exchanger during the modified third step (FD), a cooling step from the range of the minimum voltage U _L * from the point (F) until the polarization curve of the original low temperature T _L reached in point (D) of the surface charge OPE,

whereby by means of the voltage change of U _H after U _L * when the area reached (ABFDA) is increased by the surface (BFDCB) work and thus increased electrical energy is performed by the switchable pyroelectric material in the switchable pyroelectric converter.

The specified high voltage U _H can be as maximum voltage and the given low voltage U _L can be designed as minimum voltage.

Due to the existing switchable pyroelectricity voltage UPE, the applied low voltage U _L to a minimum voltage U _L * be reduced.

By means of a regulation of the voltage applied to the insulating dielectric material, the voltage source can locally adjust the polarization as a result of the crystal symmetry reduction with respect to the charged intrinsic defects or introduced defects, and redistribute charged intrinsic defects through the switching of the voltage introduced defects and thereby the crystal symmetry are lowered, whereby in the insulating dielectric material voltage-related pyroelectric phases are formed, which form a polarization of the insulating dielectric material and are used for the conversion of thermal energy into electrical energy.

The heat flow of the fluid at high temperature T _H can alternate with the heat flow of the low temperature fluid T _L be thermally coupled by a heat exchanger and an associated valve assembly, wherein a respective tempered outflow of the valve assembly flows through the heat exchanger.

The conversion of thermal energy into electrical energy can enable a return of electrical energy into an energy conversion process.

As the insulating dielectric material, an insulating dielectric single crystal may be used, and the insulating dielectric single crystal may be coated with thin-film electrodes for electrical contacting by means of preferably physical vapor deposition.

• - einen pyroelektrischen Wandler, der zumindest aus mindestens einem isolierenden dielektrischen Material mit einer kristallinen und eine Defektkonzentration aufweisenden Struktur besteht, und der zu einem schaltbaren pyroelektrischen Wandler zur Durchführung eines modifizierten Olsen-Zyklus ausgebildet ist, wobei der pyroelektrische Wandler zumindest umfasst
  • - das isolierende dielektrische Material mit einer kristallinen und eine Defektkonzentration aufweisenden Struktur, das mit Elektroden kontaktiert ist,
  • - eine Spannungsquelle,
  • - eine zur Signalerfassung dienende Verbrauchseinrichtung, wobei das elektrodenkontaktierte Material, die Spannungsquelle und die Verbrauchseinrichtung miteinander zu einem Stromkreis verschaltet sind, und
  • - einen Wärmeübertrager, der mit dem elektrodenkontaktierten Material wärmegekoppelt beabstandet in Verbindung steht,
• - eine außerhalb des schaltbaren pyroelektrischen Wandlers befindliche Ventilanordnung zur Steuerung des Zuflusses von hochtemperiertem Fluid und niedrigtemperiertem Fluid in den Wärmeübertrager, sowie
• - eine Steuer-/Regeleinrichtung, die mit der Ventilanordnung, der Verbrauchseinrichtung und der Spannungsquelle in signaltechnischer Verbindung steht, wobei mit den Signalen der Steuer-/Regeleinrichtung zumindest die Spannungsquelle zur Einstellung der Pyroelektrizitätsspannung UPE am elektrodenkontaktierten pyroelektrischen Material auf eine Mindestspannung U_L*, die gemäß dem modifizierten Olsen-Zyklus geringer als die vorgegebene, zum konventionellen Olsen-Zyklus gehörende, niedrige Spannung U_L mit U_L* < U_L ist, gesteuert wird.

In the device for converting thermal energy into electrical energy, there is a pyroelectric converter for converting thermal energy into electrical energy after the conventional Olsen cycle with a predetermined high voltage U _H and a predetermined low voltage U _L the pyroelectricity voltage UPE for the realization of the aforementioned method,
wherein according to the characterizing part of claim 9
at least the device contains

• a pyroelectric transducer comprising at least one insulating dielectric material having a crystalline and defect concentration structure and being formed into a switchable pyroelectric transducer for performing a modified Olsen cycle, the pyroelectric transducer at least comprising
  • the insulating dielectric material having a crystalline and a defect concentration structure contacted with electrodes,
  • a voltage source,
  • - A serving for signal detection consumption device, wherein the electrode-contacted material, the voltage source and the consumption device are interconnected to form a circuit, and
  • a heat exchanger which communicates with the electrode-contacted material in a heat-coupled manner,
• - A located outside of the switchable pyroelectric transducer valve assembly for controlling the inflow of high-temperature fluid and low-temperature fluid in the heat exchanger, and
• - A control / regulating device, which is in signal communication with the valve assembly, the consumption device and the voltage source, wherein at least the voltage source for adjusting the pyroelectricity voltage UPE on the electrode-contacted pyroelectric material to a minimum voltage with the signals of the control / regulating device U _L * . in accordance with the modified Olsen cycle, less than the predetermined low voltage associated with the conventional Olsen cycle U _L With U _{L *} < U _L is, is controlled.

The defective, insulating dielectric material preferably has a centrosymmetric crystal symmetry and a defect concentration at which pyroelectricity is built up by the voltage connection and which is designed to be voltage-switchable beyond the conventional Olsen cycle for pyroelectric material.

The control / regulating device can each have control lines for signal-technical connection with the valve arrangement, the consumption device and the voltage source.

The defective, insulating dielectric material may be an insulating dielectric single crystal and be occupied for electrical contacting by means of preferably physical vapor deposition with thin-film electrodes.

A first metallic electrode, the pyroelectric material as a dielectric insulator, and the second metallic electrode may form a metal-insulator-metal stack.

The heat exchanger may be connected to the valve assembly via an inlet conduit for the alternate flow of fluids through the heat exchanger and having a drain line for the fluids.

The switchable pyroelectric converter may be formed with a parallel connection of a plurality of pyroelectric materials to form a circuit, wherein the occurring pyroelectric currents add.

The switchable pyroelectric converter may be provided with a series connection of voltage source and a plurality of pyroelectric material elements, wherein the series circuit, a division of the voltage applied from the control voltage is possible to apply different voltages to the individual pyroelectric material elements, wherein the pyroelectric occurring Add voltages.

The switchable pyroelectric converter can be used in conjunction with a power supply unit for an energy converter, such as an electrolysis device as a waste heat source, wherein the switchable pyroelectric converter by means of a pump alternately controlled by the control / regulating device, the fluid at high temperature T _H and the low temperature fluid T _L is supplied by means of the valve arrangement.

The switchable pyroelectric transducer may be included in a detector for receiving radiation from the infrared region, wherein the detector consists of a thermally insulating housing or alternatively contains an additional detection element, which is located between the pyroelectric material and the housing and thus in differential circuit external interference compensated.

In the housing, an infrared transparent window, behind which the switchable pyroelectric material is disposed, are located, wherein the electrodes are connected to bushings, which allow an electrical contact or an electrical connection outside the housing, wherein outside the housing, a voltage source for Circuit and control of the pyroelectricity voltage UPE of the switchable pyroelectric material is located and wherein the controller is in communication with a parallel to the voltage source controlled signal amplification unit, for tuning the signal amplification of the electrical signals generated by the controlled / controlled pyroelectricity UPE.

The invention is based on a switchable and controllable pyroelectricity, which may occur, inter alia, even at room temperature. Thus, a broader pyroelectric material base having a wide range of thermal, dielectric and optical properties, among others, can be provided to enhance pyroelectric applications. The active material zone can be concentrated in a thermally sensitive layer and then allows a short excitation or response time, since not the entire material must be thermally tempered.
Switchability is understood to mean the generation of pyroelectric phases in the insulating dielectric material.

Controllability is understood to mean the continuous adjustment of a spontaneous polarization on the insulating dielectric material as a function of the applied voltage.

The work done by existing Olsen cycle based transducers can be increased by using voltage-switched pyroelectric materials.

In areas of energy conversion and storage, switchable pyroelectric transducers can be used to increase the efficiency of processes through waste heat recovery. At the same time synergy effects can be achieved by sharing a voltage source, eg in electrolysis processes or accumulators.

The quality factor of pyroelectric detectors defined by the ratio: signal to signal background increases with the increase of the pyroelectric coefficient, with the reduction of the specific heat capacity and with the lowering of the permittivity. The broader material basis based on the aforementioned switchable pyroelectricity makes it possible to use materials that lead to a significant increase in the quality factor. An additional control / controllability of the pyroelectric effect also enables an improved sensitivity of the detector.

Further developments and special embodiments of the invention are specified in further subclaims.

• 1 eine schematische Darstellung einer Vorrichtung zu Umwandlung von thermischer Energie in elektrische Energie mit einem schaltbaren pyroelektrischen Wandler zur Umwandlung thermischer Energie in elektrische Energie,
• 2a eine schematische Darstellung einer Parallelschaltung mehrerer Kristalle zu einem Stromkreis innerhalb des schaltbaren pyroelektrischen Wandlers,
• 2b eine schematische Darstellung einer Reihenschaltung mehrerer Kristalle zu einem Stromkreis innerhalb des schaltbaren pyroelektrischen Wandlers,
• 3a einen konventionellen Olsen-Zyklus,
• 3b eine Anwendung des in 1 dargestellten schaltbaren pyroelektrischen Wandlers mittels eines den konventionellen Olsen-Zyklus modifizierten arbeitsverbessernden Kreisprozesses,
• 4 einen Einsatz eines schaltbaren pyroelektrischen Wandlers in Verbindung mit einer Spannungsversorgungseinheit eines Energiewandlers, z.B. einer Elektrolyse-Einrichtung, als Abwärmequelle und
• 5 eine Anwendung eines spannungsschaltbaren pyroelektrischen Materials innerhalb eines Detektors zur Erfassung von Strahlung eines Infrarot-Wellenlängenbereiches (Wärmequelle).

The invention will be illustrated by means of several embodiments with reference to drawings.
Show it:

• 1 a schematic representation of a device for converting thermal energy into electrical energy with a switchable pyroelectric converter for converting thermal energy into electrical energy,
• 2a a schematic representation of a parallel connection of several crystals to a circuit within the switchable pyroelectric converter,
• 2 B a schematic representation of a series connection of several crystals to a circuit within the switchable pyroelectric converter,
• 3a a conventional Olsen cycle,
• 3b an application of the in 1 illustrated switchable pyroelectric transducer by means of a conventional Olsen cycle modified work-enhancing cycle,
• 4 a use of a switchable pyroelectric transducer in conjunction with a power supply unit of an energy converter, such as an electrolysis device, as a waste heat source and
• 5 an application of a voltage switchable pyroelectric material within a detector for detecting radiation of an infrared wavelength range (heat source).

• -den pyroelektrischen Wandler 2, der zumindest aus mindestens einem isolierenden dielektrischen Material (3) mit einer kristallinen und eine Defektkonzentration aufweisenden Struktur besteht und der zu einem schaltbaren pyroelektrischen Wandler (2) zur Durchführung eines modifizierten Olsen-Zyklus ausgebildet ist, der zumindest umfasst
  • - das isolierende dielektrische Material 3 mit einer kristallinen und eine Defektkonzentration aufweisenden Struktur, wobei das Material 3 mit Elektroden 4, 5 kontaktiert ist,
  • - eine Spannungsquelle 6,
  • - eine zur Signalerfassung dienende Verbrauchseinrichtung 7, wobei das elektrodenkontaktierte Material 3, die Spannungsquelle 6 und die Verbrauchseinrichtung 7 miteinander zu einem Stromkreis 20 verschaltet sind, und
  • - einen Wärmeübertrager 8, der mit dem elektrodenkontaktierte Material 3 beabstandet in Verbindung steht,
• - eine außerhalb des schaltbaren pyroelektrischen Wandlers 2 befindliche Ventilanordnung 9 zur Steuerung des Zuflusses von hochtemperiertem Fluid 10 und von niedrigtemperiertem Fluid 11 in den Wärmeübertrager 8, sowie
• - eine Steuer-/Regeleinrichtung 12, die mit der Ventilanordnung 9, der Verbrauchseinrichtung 7 und der Spannungsquelle 6 in signaltechnischer Verbindung steht, wobei mit den Signalen der Steuer-/Regeleinrichtung 12 zumindest die Spannungsquelle 6 zur Einstellung der Pyroelektrizitätsspannung UPE am elektrodenkontaktierten pyroelektrischen Material 3 auf eine in einem modifizierten Olsen-Zyklus gemäß 3b eingestellte Mindestspannung U_L*, die geringer als die vorgegebene, zum konventionellen Olsen-Zyklus gehörende niedrige Spannung U_L mit U_L* < U_L ist, gesteuert wird.

In 1 is a schematic representation of a device 1 for converting thermal energy into electrical energy, in which a pyroelectric transducer for converting thermal energy into electrical energy after the conventional Olsen cycle with a predetermined maximum voltage U _H and a predetermined minimum voltage U _L the pyroelectricity voltage UPE is located. According to the invention, at least the device contains 1

• the pyroelectric converter 2 at least comprising at least one insulating dielectric material ( 3 ) having a crystalline and a defect concentration structure and which is a switchable pyroelectric transducer ( 2 ) is designed to carry out a modified Olsen cycle, which comprises at least
  • - The insulating dielectric material 3 having a crystalline and a defect concentration structure, wherein the material 3 with electrodes 4 . 5 is contacted,
  • - a voltage source 6 .
  • - A serving for signal acquisition consumer device 7 wherein the electrode-contacted material 3 , the voltage source 6 and the consumer device 7 together to form a circuit 20 are interconnected, and
  • - a heat exchanger 8th that with the electrode-contacted material 3 spaced communicates,
• - One outside the switchable pyroelectric converter 2 located valve assembly 9 for controlling the inflow of high-temperature fluid 10 and low-temperature fluid 11 in the heat exchanger 8th , such as
• - a control / regulating device 12 connected to the valve assembly 9 , the consumer device 7 and the voltage source 6 is in signal communication, with the signals of the control / regulating device 12 at least the voltage source 6 for adjusting the pyroelectricity voltage UPE at the electrode-contacted pyroelectric material 3 to one in a modified Olsen cycle according to 3b set minimum voltage U _L * which is lower than the predetermined low voltage associated with the conventional Olsen cycle U _L with U _{L *} <U _L is controlled.

In the insulating dielectric material 3 With reference to room temperature 20 ° C. and normal pressure, the defect concentration can be increased by means of a treatment at higher temperature and / or under reduced pressure or by ion bombardment.

The control device 12 according to 1 for signaling connection with the valve arrangement 9 , the consumer device 7 and the voltage source 6 each control lines 13 . 14 . 15 on.

The metallic electrode 4 , the pyroelectric crystal material 3 as insulator and the metallic electrode 5 Form a Metal Insulator Metal Stack 43 ,

In this case, a pyroelectric material provided with defects, insulating dielectric material 3 used with a preferably centrosymmetric crystal symmetry and with a defect concentration at which a pyroelectricity is built up by voltage connection and which is designed to be voltage switchable beyond the conventional Olsen cycle for pyroelectric material.

The insulating dielectric material 3 may be an insulating dielectric single crystal used for electrical contacting by means of preferably physical vapor deposition with thin-film electrodes 4 . 5 is occupied.

The heat exchanger 8th is with the valve assembly 9 via an inflow line 16 for the alternate flow of fluids 10 and 11 connected and has a drain line 17 for the fluids 10 and 11 on.

• - Beschichten mindestens eines isolierenden dielektrischen Materials 3 mit einer kristallinen und eine Defektkonzentration aufweisenden Struktur mit metallischen Elektroden 4, 5 zur Ausbildung mindestens eines Metall-Isolator-Metall-Stapels 43, wobei der Metall-Isolator-Metall-Stapel 43 zu dem Stromkreis 20 mit Spannungsquelle 6, 28 und Verbrauchseinrichtung 7 gehört,
• - Anlegen/Schalten einer Spannung UPE aus der Spannungsquelle 6, 28 zur Erniedrigung der Kristallsymmetrie durch Ausbildung eines Defektkonzentrationsgradienten im isolierenden dielektrischen Material 3, wobei das isolierende dielektrische Material 3 zu einem schaltbaren pyroelektrischen Material wird, und damit
• - Erzeugen von pyroelektrischen Phasen im isolierenden dielektrischen Material 3, die eine Polarisation im Material 3 erzeugen,
• - Ankoppeln von Wärmeströmen hoher Temperatur T_H und Wärmeströmen niedriger Temperatur T_L als eingebrachte thermische Energie im vorgegeben Wechsel mittels eines Wärmeübertragers 8 an die erzeugten pyroelektrischen Phasen, wobei der Metall-Isolator-Metall-Stapel 43, die Spannungsquelle 6, 28, die Verbrauchseinrichtung 7 und der thermisch ankoppelbare Wärmeübertrager 8 einen schaltbaren pyroelektrischen Wandler 2 bilden, und
• - Abgreifen eines elektrischen Stromes als elektrische Energie aus dem Stromkreis 20 nach dem wechselseitigen thermischen Ankoppeln der Wärmeströme als Folge einer Polarisationsänderung der vorher erzeugten pyroelektrischen Phasen.

The process of converting thermal energy into electrical energy in a circuit 20 with voltage source 6 . 28 and consumption device 7 has at least the following steps

• Coating at least one insulating dielectric material 3 having a crystalline and a defect concentration structure with metallic electrodes 4 . 5 for forming at least one metal-insulator-metal stack 43 where the metal-insulator-metal stack 43 to the circuit 20 with voltage source 6 . 28 and consumption device 7 belongs,
• - Apply / switch a voltage UPE from the voltage source 6 . 28 for lowering the crystal symmetry by forming a defect concentration gradient in the insulating dielectric material 3 wherein the insulating dielectric material 3 becomes a switchable pyroelectric material, and thus
• - Creating pyroelectric phases in the insulating dielectric material 3 that has a polarization in the material 3 produce,
• - Coupling of high temperature heat flows T _H and low temperature heat flows T _L as introduced thermal energy in the predetermined change by means of a heat exchanger 8th to the generated pyroelectric phases, the metal-insulator-metal stack 43 , the voltage source 6 . 28 , the consumer device 7 and the thermally coupled heat exchanger 8th a switchable pyroelectric converter 2 form, and
• - Picking up an electric current as electrical energy from the circuit 20 after the mutual thermal coupling of the heat flows as a result of a polarization change of the previously generated pyroelectric phases.

In insulating the dielectric material 3 can be increased based on room temperature 20 ° C and normal pressure, the defect concentration by means of a treatment at a higher temperature and / or at reduced pressure or by ion bombardment.

As a pyroelectric material may be provided with a defective, insulating dielectric material 3 can be used with a preferably centrosymmetric crystal symmetry and a defect concentration at which a pyroelectricity is built up by voltage connection and which is formed over a conventional Olsen cycle for pyroelectric material out voltage switchable.

• • In einem ersten Schritt (A-B) wird ein elektrodenkontaktiertes pyroelektrisches Material des pyroelektrischen Wandlers 2 bei einer vorgegebenen hohen Spannung U_H mittels eines Wärmeübertragers und eines den Wärmeübertrager durchströmenden hochtemperierten Fluids 10 solange aufgeheizt, bis die Polarisationskurve einer hohen Temperatur T_H erreicht ist,
• • in einem zweiten Schritt (B-C) erfolgt eine isotherme Entladung der Oberflächenladung OPE über eine an das elektrodenkontaktierende pyroelektrische Material angelegte Spannungsquelle solange, bis eine vorgegebene niedrige Spannung U_L erreicht ist,
• • in einem dritten Schritt (C-D) erfolgt mittels eines den Wärmeübertrager durchströmenden niedrigtemperierten Fluids 11 ein Abkühlungsschritt im Bereich der vorgegebenen niedrigen Spannung U_L solange, bis die Polarisationskurve einer niedrigeren Temperatur T_L erreicht ist, und
• • in einem den Kreisprozess schließenden Schritt (D-A) erfolgt eine isotherme Aufladung der Oberflächenladung OPE bis zur ursprünglich vorgegebenen hohen Spannung U_H ,

wobei die Fläche (A-B-C-D-A) die verrichtete Arbeit und damit die elektrische Energie bei der Umwandlung von thermischer Energie in elektrische Energie darstellt,
wobei in Weiterentwicklung des konventionellen Olsen-Zyklus zu einem modifizierten Olsen-Zyklus/arbeitsverbesserten Kreisprozess zumindest folgende modifizierte Schritte durchgeführt werden:

• • der ursprüngliche zweite Schritt (B-C) wird durch eine Steuer-/Regeleinrichtung 12 derart zu einem spannungsdifferenzvergrößerten Schritt (B-F) modifiziert, wobei von der hohen Spannung U_H aus die vorgegebene niedrige Spannung U_L unterschreitend bis auf eine Mindestspannung U_L* verringert geschaltet wird, wobei während des modifizierten zweiten Schrittes (B-F) schrittparallel eine isotherme Entladung der Oberflächenladung OPE über die angelegte Spannungsquelle 6, 28 solange durchgeführt wird, bis die Mindestspannung U_L* im Punkt F erreicht wird,
• • der ursprüngliche dritte Schritt (C-D) wird derart zu einem Schritt (F-D) modifiziert, wobei mittels des den Wärmeübertrager 8 durchströmenden niedrigtemperierten Fluids 11 während des modifizierten dritten Schrittes (F-D) ein Abkühlungsschritt aus dem Bereich der Mindestspannung U_L* vom Punkt F aus solange erfolgt, bis die Polarisationskurve der ursprünglichen niedrigen Temperatur T_L im Punkt D mit der Oberflächenladung OPE erreicht ist,

wodurch mittels der Spannungsänderung von U_H nach U_L* bei erreichter Fläche A-B-F-D-A eine um die Fläche B-F-D-C-B erhöhte Arbeit und damit erhöhte elektrische Energie durch das schaltbare pyroelektrische Material 3 im schaltbaren pyroelektrischen Wandler 2 verrichtet wird.For switching the voltages, the conventional Olsen cycle is used, the conventional Olsen cycle comprising the following steps:

• In a first step (AB) becomes an electrode-contacted pyroelectric material of the pyroelectric transducer 2 at a given high voltage U _H by means of a heat exchanger and a heat exchanger flowing through high-temperature fluid 10 heated up until the polarization curve of a high temperature T _H is reached,
• In a second step (BC) an isothermal discharge of the surface charge OPE takes place via a voltage source applied to the electrode-contacting pyroelectric material until a predetermined low voltage is reached U _L is reached,
• In a third step (CD) takes place by means of a low-temperature fluid flowing through the heat exchanger 11 a cooling step in the range of the predetermined low voltage U _L until the polarization curve of a lower temperature T _L is reached, and
• • In a step (DA) closing the cycle process, an isothermal charging of the surface charge OPE takes place up to the originally specified high voltage U _H .

wherein the area (ABCDA) represents the work done and thus the electrical energy in the conversion of thermal energy into electrical energy,
wherein, as a further development of the conventional Olsen cycle to a modified Olsen cycle / improved work cycle, at least the following modified steps are carried out:

• • The original second step (BC) is controlled by a controller 12 thus modified to a voltage difference magnified step (BF), wherein the high voltage U _H from the given low voltage U _L below a minimum voltage U _{L *} is reduced, wherein during the modified second step (BF) stepwise parallel an isothermal discharge of the surface charge OPE on the applied voltage source 6 . 28 as long as is carried out until the minimum voltage U _{L *} reached in point F,
• The original third step (CD) is thus modified to a step (FD) using the heat exchanger 8th flowing low-temperature fluid 11 during the modified third step (FD) a cooling step from the range of the minimum voltage U _{L *} from point F until the polarization curve is at the original low temperature T _L at the point D reached with the surface charge OPE,

whereby by means of the voltage change of U _H after U _{L *} when the area ABFDA is reached, work increased by the area BFDCB and thus increased electrical energy through the switchable pyroelectric material 3 in the switchable pyroelectric converter 2 is done.

The specified high voltage U _H can be as maximum voltage and the given low voltage U _L can be designed as minimum voltage.

Due to the existing switchable pyroelectricity voltage UPE, the applied low voltage U _L to a minimum voltage U _{L *} be reduced.

By means of a regulation of the insulating dielectric material 3 applied voltage from the voltage source 6 . 28 in the pyroelectric material 3 For example, locally a stepless adjustment of the polarization resulting from the crystal symmetry decrease with respect to the charged intrinsic defects or introduced defects can be made, and the circuit can redistribute charged intrinsic defects or introduced defects, thereby lowering the crystal symmetry, thereby resulting in the insulating dielectric material 3 Voltage-related pyroelectric phases arise which cause polarization in the insulating dielectric material 3 training and be used to convert thermal energy into electrical energy.

The heat flow of the fluid 10 with high temperature T _H becomes alternating with the heat flow of the fluid 11 with low temperature T _L by means of the heat exchanger 8th and the associated valve assembly 9 thermally coupled, wherein a respective outflow stream of the valve assembly 9 the heat exchanger 8th flows.

The conversion of thermal energy into electrical energy can enable a return of electrical energy into an energy conversion process.

As insulating dielectric material 3 For example, an insulating dielectric single crystal and the insulating dielectric single crystal may be used 3 can for electrical contacting by means of preferably physical vapor deposition with thin-film electrodes 4 . 5 be occupied.

The procedure is as follows:

An insulating dielectric material 3 , For example, a single crystal (thickness between 100nm and 1mm), for example, from strontium titanate, is for electrical contacting by physical vapor deposition with thin-film electrodes 4 . 5 busy. By controlled application of the pyroelectricity voltage UPE from the voltage source 6 to the crystal 3 can in the crystal 3 locally a circuit of symmetry by redistribution of charged intrinsic defects or introduced defects in the electric field (in the order of 1MV / m) are lowered. Consequently, arise in the single crystal 3 Voltage-related pyroelectric phases that can be used to convert thermal energy into electrical energy.

The metal (4) insulator (3) metal (5) stack 43 is part of a circuit formed by means of electrical lines 20 , which additionally a voltage source 6 and a consumer device 7 , Contains eg a consumer and / or a measuring device.

A heat flow of the fluid 10 with high temperature T _H can alternate with a heat flow of the fluid 11 with low temperature T _L by means of the heat exchanger 8th and the valve assembly 9 be thermally coupled. The outflow stream of the valve assembly 9 flows through wire 16 the heat exchanger 8th ,
The assembly of circuit 20 , Crystal material 3 and heat exchangers 8th as well as voltage source 6 is used as a switchable pyroelectric converter 2 designated (SPW).

The 2a shows an inner part of a switchable pyroelectric transducer 2 with a possible parallel interconnection of several crystal materials 3 . 18 . 19 to a circuit 20 , The illustration includes a parallel connection 21 from voltage source 6 and the electrode-contacting crystal materials / elements 3 . 18 . 19 , This allows the individual material elements 3 . 18 . 19 an identical voltage from the controller 12 are applied while the occurring pyroelectric currents add up.

Furthermore, in 2 B a series connection 22 from voltage source 6 and the material elements 3 . 18 . 19 shown. Through the series connection 22 is a breakdown of the control 12 applied voltage possible to different voltages on the individual material elements 3 . 18 . 19 create, with the occurring pyroelectric voltages add up.

• • Im ersten Schritt (A-B) wird das elektrodenkontaktierte schaltbare pyroelektrische Kristallmaterial 3 bei einer hohen Spannung U_H mittels des Wärmeübertragers 8 und des den Wärmeübertrager 8 durchströmenden hochtemperiertem Fluids 10 solange aufgeheizt, bis die Polarisationskurve einer hohen Temperatur T_H im Punkt B erreicht ist.
• • Im zweiten Schritt (B-C) wird durch die Steuer-/Regeleinrichtung 12 gesteuert die niedrige Spannung U_L bis auf die Mindestspannung U_L* verringert.
• • Während des zweiten Schrittes (B-C) erfolgt zeitparallel eine isotherme Entladung der Oberflächenladung OPE über die angelegte Spannungsquelle 6 solange, bis die Mindestspannung U_L* erreicht ist.
• • Im dritten Schritt (C-D) erfolgt mittels des den Wärmeübertrager 8 durchströmenden niedrigtemperierten Fluids 11 ein Abkühlungsschritt im Bereich der Mindestspannung U_L* solange, bis die Polarisationskurve der ursprünglichen niedrigen Temperatur T_L im Punkt F erreicht ist.
• • In einem den Kreisprozess 24 schließenden vierten Schritt (D-A) erfolgt eine isotherme Aufladung der Oberflächenladung OPE von der Mindestspannung U_L* aus bis zur maximalen Spannung U_H .

In the 3b is an application of in 1 shown switchable pyroelectric transducer 2 in the form of a versus the conventional Olsen cycle 25 who in 3a is presented, modified and improved work cycle 24 shown. The illustrated, provided with arrows for an aligned process direction direction modified work improved cycle 24 consists of the four steps:

• In the first step (AB) becomes the electrode-contacted switchable pyroelectric crystal material 3 at a high voltage U _H by means of the heat exchanger 8th and of the heat exchanger 8th flowing through high-temperature fluid 10 heated up until the polarization curve of a high temperature T _H at the point B is reached.
• • In the second step (BC) is by the control 12 controls the low voltage U _L to the minimum voltage U _{L *} reduced.
• During the second step (BC), an isothermal discharge of the surface charge OPE takes place parallel to time via the applied voltage source 6 until the minimum voltage U _{L *} is reached.
• • In the third step (CD) takes place by means of the heat exchanger 8th flowing low-temperature fluid 11 a cooling step in the range of the minimum voltage U _{L *} until the polarization curve of the original low temperature T _L at the point F is reached.
• • In one the cycle process 24 closing fourth step (DA) there is an isothermal charge of the surface charge OPE from the minimum voltage U _{L *} off to the maximum voltage U _H ,

By means of the infinitely adjustable voltage of U _H after U _{L *} In addition to the surfaces ABCDA of the conventional Olsen cycle, with the modified surface ABFDA, work increased by the surface BFDCB and thus increased energy is performed and tapped.

Thus, the set goal is achieved that in 3a illustrated conventional area 44 the associated work in comparison between the 3a and 3b in 3b through the switchable pyroelectric converter 2 around the additional area 45 to a total area 46 can be increased. Due to the switchable pyroelectricity, the applied low voltage U _L to an applied minimum voltage U _L * , at no surface charge O _PE exists, can be reduced.
In addition, the absolute temperature range can be chosen freely, since the effect can be used at any temperature which would otherwise be fixed to a temperature interval close to below the intrinsic Curie temperature.
In the point F the original state of a preferably centrosymmetric crystal symmetry is present in the insulating dielectric material. In the area between the point F and the point D become at the low temperature T _L built up by the applied voltage UPE pyroelectric phases, so starting from point D by increasing the voltage and in the point A by a heating step, the conversion of thermal energy based on the high temperature T _H is performed in electrical energy in the modified cycle FDABF. Upon reaching the point F again is the variable polarization on the insulating dielectric material 3 significantly reduced or no longer available.

In summary, as in 3b is represented by the cycle according to the invention 24 in 3b enclosed area 46 , that is, the total work done, compared to the enclosed dotted area 44 in 3a the conventional Olsen cycle 25 around the additional area hatched 45 increase.

In the 4 is an application of the switchable pyroelectric transducer 2 in conjunction with a power supply unit 28 an energy converter, eg an electrolysis device 37 as waste heat source, shown. The switchable pyroelectric converter 2 be by means of a pump 27 alternately controlled by the controller 12 the fluid 10 with the high temperature T _H (H-High) and the fluid 11 with low temperature T _L (L-Low) by means of the valve assembly 9 fed. By means of electrolysis in the electrolysis facility 37 can be achieved by the supply of electrical energy from the switchable pyroelectric converter 2 at least one input material 38 in split / separated products 39 be transferred. The by means of the control / regulating device 12 switchable pyroelectric converters 2 is via at least one electrical line 40 with the electrolysis device 37 for transmitting in the converter 2 connected electrical energy. Also the voltage source 28 stands with the electrolysis facility 37 via wire 41 and the converter 2 via wire 42 in connection. The control device 12 is via assigned connection lines / control lines 23 with the voltage source 28 , the converter 2 , the pump 27 , the valve assembly 9 and the electrolysis device 37 in connection.

In the 3b represented and controlled conversion of thermal energy into electrical energy also allows a return of electrical energy in the in 4 illustrated energy conversion process. By using a common voltage source 6 . 28 Synergy effects can be achieved. A control device 12 is used to control the connection of the heat flows and the pump power. By additional control of the performance of the energy converter 7 , the switchable pyroelectric converter 2 and the voltage source 6 . 28 can the energy efficiency of the device 1 increase.

This is what the 5 a second application of a voltage switchable pyroelectricity insulating dielectric crystal material 2 in a detector 29 for receiving radiation 33 from the infrared range. The detector 29 consists of a thermally insulating housing 30 or alternatively includes an additional detection element 31 which is not lit, between the crystal material 3 and the housing 30 is located and thus compensated in differential circuit external interference. To the housing 30 heard an infrared transparent window 32 behind which is the switchable pyroelectric crystal material 3 located. At the same time is the switchable pyroelectric crystal material 3 on the detection element 31 , The contacting of the crystal material (eg an insulating dielectric single crystal) 3 takes place as in 1 shown and described. The infrared-transparent window 32 of the housing 30 facing electrode 4 is characterized by being the infrared radiation 33 strongly absorbed and direct, with the pyroelectric crystal material 3 related heat source 33 , which serves to realize the modified Olsen cycle represents. The electrode 5 on the back of the crystal material 3 acts as an ohmic contact in conjunction with the detection element 31 , The electrodes 4 . 5 are with bushings 34 . 35 connected, the electrical contact or an electrical connection outside the housing 30 enable. Outside the case 30 there is a voltage source 6 for switching and controlling the pyroelectricity voltage UPE of the pyroelectric crystal material 3 , The control device 12 connected to a parallel to the voltage source 6 controlled signal amplification unit 36 is used to tune the signal gain of the electrical signals generated by the controlled pyroelectricity.

The invention is intended to contribute to the generation and switching of pyroelectricity in insulating dielectric materials 3 which, for reasons of symmetry, do not appear pyroelectric with respect to their atomic arrangement in nature. This happens in that targeted by atomic design and defect control or defect control, the preferably centrosymmetric crystal symmetry is locally lowered or increased.

The modification and switching of the original non-pyroelectric materials 3 can also be realized by means of external electric fields.

As a result, a broader pyroelectric material base having a wide range of thermal, dielectric and optical properties can be provided for energy converter and sensor applications.

Through the use of switchable pyroelectric materials 3 In already existing applications, an increase in efficiencies and performance indicators can be achieved.

LIST OF REFERENCE NUMBERS

1

device

2

Switchable pyroelectric converter

3

Switchable pyroelectric material / pyroelectric crystal material

4

First electrode

5

Second electrode

6

voltage source

7

consuming device

8th

Heat exchanger

9

valve assembly

10

High temperature fluid

11

Low-temperature fluid

12

Control / regulating device

13

First control line

14

Second control line

15

Third control line

16

inflow line

17

drain line

18

Second crystal

19

Third crystal

20

circuit

21

parallel connection

22

series connection

23

interconnectors

24

modified Olsen cycle / cycle process

25

conventional Olsen cycle

26

Facility

27

pump

28

Power supply unit

29

radiation detector

30

casing

31

detection element

32

window

33

Infrared radiation

34

First implementation element

35

Second implementation element

36

Signal amplification unit

37

Electrolyzer

38

feedstock

39

Products

40

Electrical line

41

Electrical line

42

Electrical line

43

Metal-insulator-metal stack

44

Area of the conventional Olsen cycle

45

Additional surface due to switchable pyroelectricity

46

Area of the modified cycle process

U _L

Low voltage / minimum voltage

U _{L *}

minimum voltage

U _H

High voltage / maximum voltage

T _H

High temperature (high)

T _L

Low temperature

PE

pyroelectricity

U _PE

Pyroelektrizitätsspannung

O _PE

pyroelectric surface charge

A

Point of an Olsen cycle / cycle process

B

Point of an Olsen cycle / cycle process

C

Point of an Olsen cycle / cycle process

D

Point of an Olsen cycle / cycle process

F

Point of a modified Olsen cycle / cycle process

Claims (20)

Method for converting thermal energy into electrical energy in a circuit (20) having a voltage source (6, 28) and consuming device (7), comprising the following steps: - coating at least one insulating dielectric material (3) having a crystalline and a defect concentration structure metallic electrodes (4, 5) for forming at least one metal-insulator-metal stack (43), the metal-insulator-metal stack (43) being connected to the circuit (20) with voltage source (6, 28) and consumer device ( 7), applying / switching a voltage UPE from the voltage source (6, 28) to lower the crystal symmetry by forming a defect concentration gradient in the insulating dielectric material (3), the insulating dielectric material (3) becoming a switchable pyroelectric material, and thus - generating pyroelectric phases in the insulating dielectric material (3) having a polarization in the Material (3), coupling high temperature heat flows T _H and low temperature heat flows T _L as introduced thermal energy in a predetermined change by means of a heat exchanger (8) to the generated pyroelectric phases, wherein the metal-insulator metal stack (43 ), the voltage source (6, 28), the consumption device (7) and the thermally coupled heat exchanger (8) form a switchable pyroelectric converter (2), and - tapping an electric current as electrical energy from the circuit (20) to the mutual thermal coupling of the heat flows as a result of a change in polarization of the previously generated pyroelectric phases, characterized in that the pyroelectric material is provided with a defect, insulating dielectric material (3) with a centrosymmetric Crystal symmetry and a defect concentration is used, is built on the by turn-on a pyroelectricity and is made voltage switchable over a conventional Olsen cycle for pyroelectric material, wherein the switching of the voltages of the conventional Olsen cycle is used, the conventional Olsen cycle comprises the following steps: In a first step (AB), an electrode-contacted pyroelectric material of the pyroelectric transducer (2) is heated at a predetermined high voltage U _H by means of a heat exchanger and a high-temperature fluid (10) flowing through the heat exchanger until the polarization curve of a high temperature T _{H is} reached, • in a second step (BC), an isothermal discharge of the surface charge OPE via a voltage applied to the electrode-contacting pyroelectric material voltage source until a predetermined low Voltage U _{L is} reached, • in a third step (CD) by means of a low-temperature fluid (11) flowing through the heat exchanger, a cooling step in the range of the predetermined low voltage U _L until the polarization curve of a lower temperature T _{L is} reached, and in a step (DA) closing the cycle process, an isothermal charge of the surface charge OPE is made up to the originally predetermined high voltage U _H , the area (ABCDA) representing the work done and thus the electrical energy in the conversion of thermal energy into electrical energy, wherein, as a further development of the conventional Olsen cycle, at least the following modified steps are carried out: the original second step (BC) is modified by a control device (12) in such a way to a voltage difference-enlarged step (BF), wherein the high voltage U _H from the given low sp oltage U _L is switched among border to a minimum voltage U _L reduces _*, where during the modified second step (BF) step parallel isothermal discharge the surface charge OPE on the applied voltage source (6, 28) is carried out until the minimum voltage U _{L *} is reached in point (F), the original third step (CD) is modified to a step (FD) such that by means of the low-temperature fluid (11) flowing through the heat exchanger (8) during the modified third step (FD) a cooling step from the range of the minimum voltage U _{L *} from the point (F) until the polarization curve of the original low temperature T _{L is reached} in the point (D) with the surface charge OPE, whereby by means of the voltage change from U _H to U _{L *} at surface area (BFDCB) increased work and thus increased electrical energy through the switchable pyroe lektrische material (3) in the switchable pyroelectric transducer (2) is performed. Method according to Claim 1 , characterized in that the defect concentration is increased by means of a treatment at a higher temperature and / or at reduced pressure or by means of ion bombardment in the insulating diektrischen material (3) based on room temperature (20 ° C) and normal pressure. Method according to Claim 1 , characterized in that the predetermined high voltage U _{H are formed} as the maximum voltage and the predetermined low voltage U _L as the minimum voltage. Method according to one of Claims 1 to 3 , characterized in that due to the existing switchable pyroelectricity voltage UPE the applied low voltage U _{L is} reduced to a minimum voltage U _{L *} . Method according to one of Claims 1 to 4 characterized in that by means of a regulation of the voltage applied to the insulating dielectric material (3) from the voltage source (6, 28) in the pyroelectric material (3) locally a stepless adjustment of the polarization resulting from the crystal symmetry reduction with respect to charged intrinsic defects or introduced defects and the circuit is a redistribution of charged intrinsic defects or introduced defects and thereby the crystal symmetry is lowered, whereby in the insulating dielectric material (3) voltage-related pyroelectric phases are formed, the one polarization in the insulating dielectric material (3 ) and used to convert thermal energy into electrical energy. Method according to Claim 1 Characterized in that the heat flow of the fluid (10) at a high temperature T _H alternating with the heat flow of the fluid (11) low temperature T _L by means of the heat exchanger (8) and the associated valve arrangement (9) is thermally coupled, wherein a respective Outflow of the valve assembly (9) flows through the heat exchanger (8). Method according to one of Claims 1 to 6 , characterized in that the conversion of thermal energy into electrical energy allows a return of electrical energy in an energy conversion process. Method according to one of Claims 1 to 7 , characterized in that as insulating Dielectric material (3) is an insulating dielectric single crystal is used and the insulating dielectric single crystal (3) for electrical contacting by means of physical vapor deposition with thin-film electrodes (4, 5) is occupied. Device (1) for converting thermal energy into electrical energy, in which a pyroelectric converter for converting thermal energy into electrical energy after the conventional Olsen cycle with a predetermined high voltage U _H and a predetermined low voltage U _{L of} the pyroelectricity voltage U _PE is to implement the method according to one of Claims 1 to 8th in which the device (1) contains at least - a pyroelectric transducer, which consists of at least one insulating dielectric material (3) with a crystalline structure and a defect concentration, and which leads to a switchable pyroelectric transducer (2) for carrying out a modified olsenic Cycle is formed, which comprises at least - the insulating dielectric material (3) having a crystalline structure, which is contacted with electrodes (4, 5), - a voltage source (6), - a signal detecting means serving for consumption (7), wherein the electrode-contacted Material (3), the voltage source (6) and the consumption device (7) are interconnected to a circuit (20), and - a heat exchanger (8), the heat-coupled with the electrode-contacted material (3) is in communication, a - outside the switchable pyroelectric converter (2) located valve assembly (9) for controlling the Inflow of high-temperature fluid (10) and low-temperature fluid (11) into the heat exchanger (8), and - a control device (12) connected to the valve assembly (9), the consumption device (7) and the voltage source (6 ) is in signaling connection, wherein with the signals of the control / regulating device (12) at least the voltage source (6) for adjusting the pyroelectricity voltage UPE at the electrode-contacted pyroelectric material (3) to a minimum voltage U _L * according to the modified Olsen cycle is less than the predetermined, belonging to the conventional Olsen cycle, low voltage U _L with U _{L *} <U _L is controlled. Device after Claim 9 , characterized in that in the insulating dielectric material (3) based on room temperature (20 ° C) and normal pressure, the defect concentration is increased by means of a treatment at a higher temperature and / or at reduced pressure or by ion bombardment. Device after Claim 9 or 10 , characterized in that as the pyroelectric material is provided with a defect, insulating dielectric material (3) having a preferably centrosymmetric crystal symmetry and a defect concentration is built on the by turn-on a pyroelectricity and beyond the conventional Olsen cycle for pyroelectric material addition is formed voltage switchable. Device after Claim 9 , characterized in that the control / regulating device (12) for signaling connection with the valve assembly (9), the consumption device (7) and the voltage source (6) each have electrical control lines (13, 14, 15). Device according to one of Claims 9 to 12 , characterized in that the insulating dielectric material (3) is an insulating dielectric single crystal and is covered with thin-film electrodes (4, 5) for electrical contacting by means of physical vapor deposition. Device after Claim 9 , characterized in that the metallic electrode (4), the pyroelectric material (3) as a dielectric insulator and the metallic electrode (5) form a metal-insulator-metal stack (43). Device after Claim 9 , characterized in that the heat exchanger (3) with the valve assembly (9) via an inlet line (16) for the alternate flow of the fluids (10, 11) through the heat exchanger (3) is connected through and a drain line (17) for the Fluids (10, 11). Device after Claim 9 , characterized in that the switchable pyroelectric transducer (2) with a parallel connection of a plurality of pyroelectric materials (3, 18, 19) to the circuit (20) is formed, wherein the occurring pyroelectric currents add. Device after Claim 9 , characterized in that the switchable pyroelectric converter (2) with a series circuit (22) of voltage source (6) and a plurality of pyroelectric material elements (3, 18, 19) is formed, wherein by the series circuit (22) a distribution of the control - / regulating device (12) applied voltage is possible to apply different voltages to the individual pyroelectric material elements (3, 18, 19), wherein the occurring pyroelectric voltages add up. Device after Claim 9 , characterized in that the switchable pyroelectric Converter (2) in connection with a power supply unit (28) for an energy converter (37) is used as a waste heat source, wherein the switchable pyroelectric converter (2) by means of a pump (27) alternately controlled by the control / regulating device (12) the fluid (10) high temperature T _H and the low temperature fluid (11) T _{K is} supplied by means of the valve assembly (9). Device according to one of Claims 9 to 18 , characterized in that the switchable pyroelectric transducer (2) is contained in a detector (29) for receiving radiation (33) from the infrared region, wherein the detector (29) consists of a thermally insulating housing (30) or alternatively an additional one Detection element (31), which is located between the pyroelectric material (3) and the housing (30) and thus compensated in differential circuit external interference. Device after Claim 19 characterized in that the housing (30) comprises an infrared transparent window (32), behind which is the switchable pyroelectric material (3), the electrodes (4, 5) being connected to bushings (34, 35), which allow an electrical contact or an electrical connection outside the housing (30), wherein outside the housing (30) is a voltage source (6) for switching and controlling the pyroelectricity voltage UPE of the pyroelectric material (3) and wherein the control / Control device (12) which is connected to a parallel to the voltage source (6) controlled signal amplification unit (36), for tuning the signal amplification of the electrical signals generated by the controlled / regulated pyroelectricity UPE.

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