摘要:
A system is disclosed, including: a plurality of Bragg gratings distributed in positions transversely to the direction of flow of an exhaust gas in an exhaust gas channel of the device; an optical wave guide structure including at least one optical wave guide and in which the Bragg gratings are embodied; a heating device arranged adjacently to the Bragg gratings and through which the Bragg gratings are subjected to heat, or a cooling device arranged adjacently to the Bragg gratings, through which the Bragg gratings are subjected to cold; at least one light source for irradiating light into the optical wave guide structure; and at least one signal processing device which determines, from light backscattered from Bragg gratings in the optical wave guide structure against its original direction of diffusion, the speed of the flow of the exhaust gas.
摘要:
A wind energy installation is disclosed. The wind energy installation includes a rotor with at least one rotor blade. The wind energy installation includes at least one wind speed measuring system. The at least one wind speed measuring system optically measures the vibrations of an optical fiber due to vortex shedding.
摘要:
A device for generating exhaust gas including a exhaust gas channel and a system. The system includes: a plurality of Bragg gratings distributed in positions transversely to the direction of flow of an exhaust gas at the end of the exhaust gas channel; an optical wave guide structure includes at least one optical wave guide and the Bragg gratings; and a heating device arranged adjacently to the Bragg gratings and through which the Bragg gratings are subjected to heat, or a cooling device arranged adjacently to the Bragg gratings, through which the Bragg gratings can be subjected to cold. The optical wave guide structure and the heating device or the cooling device are arranged at the end of the exhaust gas channel at a distance from an outlet of the exhaust gas into the surroundings of the device.
摘要:
The invention relates to a method for determining the temperature of a surface coating of rotating blades mounted in a non-positive-displacement machine with a rotor shaft rotationally mounted in a housing, during which electromagnetic waves are emitted in a duct in an area of the rotating blades by at least one means for generating electromagnetic waves. The electromagnetic waves are reflected, at least in part, by at least one rotating blade. The reflected portions of the electromagnetic waves are received by at least one receiving means and the temperature of the surface coating of the rotating blades is determined from a distribution of intensity of the received electromagnetic waves. The invention also relates to a method for determining the temperature of a surface coating of guide vanes mounted in a rotationally fixed manner in a non-positive-displacement machine with a housing, and to a device for carrying out the method.
摘要:
A method and apparatus for monitoring changes in temperature or strain, using fiber Bragg gratings (FBG). The Method and apparatus is advantageously useful for the measurement under harsh conditions, such as by combustion turbines. The invention uses the wavelength shift which is caused by temperature or strain changes at the FBG and the changing of the refraction index of the fiber.
摘要:
A magnetic field is measured with the aid of the Faraday effect. Light is coupled into a Faraday element subjected to the magnetic field, the light having a linearly polarized first component at a first wavelength and an unpolarized second component at a second wavelength different from the first. A light signal is coupled out of the Faraday element and is split optically into a first light signal component with the first wavelength and a second light signal component with the second wavelength. A first measurement signal is derived from the first light signal component and a second measurement signal is derived from the second light signal component and these are used to form a corrected measurement signal S. In this way, attenuation influences in the transmission paths can be largely compensated for, even when measuring a magnetic field which is constant over time or a magnetic field with a component which is constant over time.
摘要:
In a medical instrument for insertion into an examination subject, as well as a medical examination device or treatment device employing such an instrument, the instrument has an elongated instrument body formed by a number of successively arranged rigid sections, with respective, successive sections being connected to one another via articulated joints which can be angled relative to one another. At least one optical fiber supplied with light is conducted along the instrument body, and at least one fiber Bragg grating is fashioned in the optical fiber in a region adjacent to a joint which is deformed to a degree corresponding to angling of the adjacent sections to the joint, thereby modulating the light in the optical fiber.
摘要:
Method and system for measuring an electric current in a current conductor, two opposing light signals are transmitted through a Faraday element surrounding the current conductor and, after the passage through the Faraday element, are split, respectively, into two partial light signals. From these partial light signals, an intensity-normalized signal is derived for each partial light signal. Provision is made of a Faraday element having a negligible circular birefringence, and a signal processing unit for deriving a vibration-independent and temperature-independent measured signal.
摘要:
A fiber-optic vibration sensor for generators in power stations is disclosed. The sensor includes an optical fiber which has a freestanding end, wherein the freestanding end is caused to oscillate under the influence of vibrations, and the resulting oscillations are detected as a measure for the vibrations. Only the net weight of the optical fiber serves as a centrifugal mass.
摘要:
A rotor blade of a wind energy installation has a wall forming an outer shell, and at least one pressure measurement device arranged inside the rotor blade. The pressure measurement device includes a hollow body that is closed in a gastight fashion and has at least one pressure-dependent deformable diaphragm. At least one optical strain sensor is non-positively connected to each diaphragm. In a method using the pressure measurement device, the wind force is determined at wind energy installations by an evaluation unit which determines a comparison value indicating the difference between the pressure at the side of the outer shell facing the wind and the pressure at the side of the outer shell averted from the wind. A measured value for the wind force acting on the rotor blade is determined from the comparison value. The method can be used for optimized operation and/or protection of wind energy installations.