EP2470970A1

EP2470970A1 - Method and arrangement for monitoring a component

Info

Publication number: EP2470970A1
Application number: EP10743106A
Authority: EP
Inventors: Roland Busch; Florian Krug
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2009-08-26
Filing date: 2010-08-11
Publication date: 2012-07-04
Also published as: US20120158186A1; DE102009038883A1; WO2011023553A1

Abstract

The invention relates to a method and an arrangement for monitoring a component which, as part of a solar power system, receives and converts solar energy using a receiver. The temperature of the receiver of the component is determined using a remote monitoring method. The component is then adjusted or corrected in accordance with the temperature.

Description

description

The invention relates to a method and an arrangement for monitoring a component which, as part of a solar system, receives and converts solar energy with the aid of a receiver. The term "solar system" summarizes systems of different types. These include, for example, so-called "Concentrated Solar Power, CSP" systems, solar thermal systems, "parabolic trough" systems or "Concentrated Solar Power Parabolic Trough" systems. Concentrator photovoltaic or "Concentrated Photovoltaic, CPV" systems are also covered by this term.

In the case of the systems mentioned, in principle incident sunlight or solar energy is bundled with the aid of mirrors and fed to a receiver ("receiver") .The receiver is arranged in a mirror focal point, absorbs the solar energy supplied to it and converts it.

In a parabolic trough plant, the receiver includes, for example, a molten salt and thermal oil as a medium. The bundled solar energy heats the oil or medium that is fed to a heat exchanger. For example, steam is formed in a second circuit via the heat exchanger, which steam is supplied to a steam turbine for the formation of electrical energy.

In principle, it is also conceivable to evaporate the medium of the receiver in order to supply it to the heat exchanger in vapor form.

A concentrator photovoltaic or "Concentrated Photovoltaic, CPV" system has a number of substantially planar modules. Each module includes There are a number of mirrors. Each of the mirrors focuses incident sunlight or solar energy on an associated receiver, which converts solar energy directly into electrical energy.

In the case of the systems mentioned, the mirrors used are aligned according to the predetermined position of the sun with the aid of automated control. Due to systemic inaccuracies of the control, the mirrors used are no longer optimally aligned with the current position of the sun over time so that the energy system loses its efficiency. Further losses are caused by aging of individual plant components. For example, in parabolic trough systems, the mirror surfaces and the receivers are exposed to environmental factors that contribute to their wear and thus reduce the efficiency. The same applies to the concentrator photovoltaic systems whose components are also adversely affected by environmental factors.

So far, components are checked at regular intervals, so that defective components can be renewed if necessary.

This type of maintenance is carried out by specially trained personnel and is therefore both time-consuming and costly.

Defective components can not be detected in advance in their number. Also, they can not be located in the plant itself.

Only the reduced efficiency or increasing losses can, to a limited extent, provide an indication that a certain number of defective components must be present in the system. If the performance of the system falls off in terms of time, however, there could also be a defective or inaccurate tracking of the mirrors to the position of the sun. In order to recognize this, extensive checks would first have to be made with regard to defective components in order to subsequently be able to conclude that the mirrors had been misadjusted.

It is therefore an object of the present invention to provide an improved method and an arrangement configured for carrying out the method, with which a monitoring of a component of a corresponding system is ensured.

This object is solved by the features of patent claim 1 and by the features of claim 9.

Advantageous developments are specified in the respective subclaims. The method according to the invention monitors a component which, as part of a solar system, receives and converts solar energy with the aid of a receiver.

By means of a wireless remote monitoring method, the temperature of the receiver of the component is determined. In

Dependent on the determined temperature is then an adjustment or correction of the component.

In this case, active and passive remote temperature measuring methods can be used.

Active temperature measurement methods are preferably based on the so-called "Raman spectroscopy".

In this case, a matter to be examined is irradiated with monochromatic light, usually from a laser. in the

Spectrum of light scattered on the sample, other frequencies are observed in addition to the irradiated frequency (Rayleigh scattering). The frequency differences to the incident The light corresponds to the energy of rotational, vibrational, phonon or spin-flip processes characteristic of the material. From the spectrum obtained, it is possible, similar to the spectrum of infrared spectroscopy, to draw conclusions about the investigated substance and thus also on its temperature.

Other methods use high-frequency radiation (microwaves) for temperature measurement. Preferably, such systems use a "Coherent FMCW Reflectometric", where the abbreviation "FMCW" stands for "Frequency Modulated Continuous Wave" and describes the measurement signal used.

Passive temperature telemetry analyzes the heat radiation emitted by an object. In the case of the present invention, the latter passes outward through the mirrors and can thus be analyzed.

In the method according to the invention, infrared remote monitoring is thus preferably used. With their help, an IR beam is directed from the remote monitoring system via the associated mirror to the receiver to determine by scanning the outside temperature.

In another preferred embodiment, microwaves are used. The microwaves are directed as a beam from a remote monitoring system via the associated mirror on the receiver to determine by scanning the outside temperature.

The beam is reflected off the surface of the receiver and returned to the remote monitoring system via the mirror. By comparison between the sent

Signal and the received signal, it is possible to return to the measured temperature of the target object - here the reflector. By the method according to the invention the temperature at the surface of the receiver is determined. As a result, deviations of the determined temperature from a setpoint temperature are easily detectable.

In the event of deviations, it may be concluded that the mirror has been misaligned or that the mirror has been damaged.

This makes it possible to determine defective components accurately and locally limited in advance.

An optimized alignment of the mirrors of the system in the sense of an adaptive control can be realized just as easily as the finding and the replacement of defective components.

The inventive method allows, for example, in a parabolic trough installation to scan or monitor a system line with a length of 10 m to 200 m with only one remote monitoring device.

The method according to the invention enables a substantial increase in the lifetime of the system, since defective components can be replaced in a timely manner without damaging the system - with minimal expenditure of personnel and time.

The invention will be explained in more detail with reference to a drawing. Showing:

1 shows a parabolic trough installation, in which the method according to the invention finds application,

2 shows the method according to the invention, illustrated on a mirror PS with receiver REC of the parabolic trough installation PRA from FIG. 1,

3 shows a concentrator photovoltaic system in which the method according to the invention finds application, FIG 4 shows the orientation of the modules in the system shown in FIG 3,

5 is an enlarged detail view of the system shown in FIG 3,

6 shows the inventive method, shown on a mirror with receiver of the concentrator photovoltaic system of FIG. 3

1 shows a parabolic trough installation PRA in which the method according to the invention is used.

The parabolic trough installation PRA has a number of parabolic mirrors PS which concentrate incident sunlight onto an associated receiver REC. The receiver REC is thus arranged along a focal line of the associated parabolic mirrors PS.

The parabolic mirrors PS are arranged in a channel shape and are permanently tracked to the daily running of the sun. As a result, the incident solar radiation is optimally concentrated on the associated receiver REC.

The REC receiver consists of a specially coated absorber tube embedded in a vacuum-tight glass tube. The solar radiation acting on the receiver REC, for example, heats a thermal oil flowing in the absorber tube to 400 degrees Celsius. The thermal oil is then passed through a heat exchanger, not shown here, to produce water vapor using the heat exchanger in a connected second circuit. The steam is forwarded to a turbine system, not shown here for power generation. Typical power plant outputs range between 25 MW and 200 MW at peak times. In the parabolic trough PRE shown here, individual collector strands or parabolic mirror gutter strands may have a length L of 20 meters to 150 meters depending on the type of construction. For reasons of cost, the parabolic mirrors PS of the parabolic trough unit PRE are usually only uniaxially adjusted to the position of the sun - they are usually arranged in a north-south direction and the sun is tracked from east to west during the course of the day.

FIG. 2 shows the method according to the invention, illustrated on a mirror PS with receiver REC of the parabolic trough installation PRA from FIG. 1.

Incident sunlight SL is focused by means of the mirror PS on the receiver REC.

Infrared signals or microwave signals are directed as Messsigna- Ie MS from a remote monitoring system FUW not shown here on the associated mirror PS to the receiver REC.

In this embodiment, the measurement signal MS is selectively directed to the receiver REC.

The measurement signal MS is reflected by the surface of the receiver REC and passes back via the mirror PS back to the remote monitoring system FUW.

By comparing between the transmitted measurement signal and the received measurement signal, it is possible to return to the measured temperature of the target object - here to the temperature of the reflector REC.

On the basis of the determined temperature of the receiver REC, an optimized alignment of the mirror PS on the daily level can then be carried out by regulation in order to increase the system performance.

It is also possible, based on the determined temperature

- Damage to the mirror PS or

- an aging of the mirror surface or - Damage to the receiver or

- aging of the receiver surface

to detect. Based on the results of the temperature measurement, the defective or aged system parts can then be exchanged.

Above, an active temperature remote monitoring was used and described, but of course, a passively configured temperature remote monitoring can be used, which analyzes the heat radiation reflected by the receiver to the outside.

3 shows a concentrator photovoltaic system CPV, in which the inventive method is used.

The plant CPV here has a number of 5 modules MOD in a horizontal arrangement (row) and a number of 6 modules MOD in a vertical arrangement (column).

The modules MOD are essentially flat. Each module MOD includes a number of mirrors, as will be illustrated in the following figures. In the CPV system shown here, the mirrors are aligned according to the position of the sun using automated control. By controlling all 5 * 6 modules MOD simultaneously tracked via a module carrier of the sun.

4 shows possibilities of aligning the modules MOD in the system CPV shown in FIG.

In this case, the modules MOD are preferably pivoted about the associated module carrier about a first axis EA in order to align the mirrors of the associated modules with the position of the sun. Alternatively or additionally, the modules MOD are pivoted about the associated module carrier about a second axis ZA in order to align the mirrors of the associated modules with the position of the sun.

5 shows an enlarged detail of the system shown in FIG 3.

Individual mirrors of a module can be seen in the upper left image area, while other modules with mirrors arranged in them can be seen in the remaining image area.

FIG. 6 shows the method according to the invention, illustrated on mirrors PS1, PS2 with associated receiver REC 61 of the embodiment CPV from FIG. 3.

Incident sunlight SL is focused onto a receiver REC 61 by means of a first mirror PSl and by means of a second mirror PS2.

In a preferred refinement, an optical element, in particular a prism or an optical element called "optical rod", is additionally used in order to optimize the focusing on the receiver REC 61.

The receiver REC 61 is configured as a semiconductor or as a photovoltaic element and converts the sunlight SL or its solar energy bundled onto it directly into electrical energy.

Infrared signals or microwave signals are directed as measurement signals MS from a remote monitoring system FUW not shown here via the associated mirrors PSL, PS2 to the receiver REC 61.

The measuring signal MS is reflected by the receiver REC 61 and returns via the two mirrors PS1, PS2 back to the remote monitoring system FUW. In the case of CPV systems, an entire module is preferably scanned flat by means of the measurement signal MS in order to determine a representative temperature of the entire module.

By comparing the transmitted measurement signal with the received measurement signal, it is possible to deduce the measured temperature of the target object - in this case the representative temperature of the module and thus the reflectors REC 61 contained therein.

On the basis of the determined representative temperature of the module, an optimized alignment to the daily level can be achieved by regulation.

It is also possible, based on the determined temperature

- Damage to the mirror of the module or

- an aging of the mirror surface or

- Damage to the receiver of the module or

- aging of the receiver surface

to detect.

Based on the results of the temperature measurement, the defective or aged system parts can then be exchanged.

Previously, an active remote temperature monitoring was used and described, but of course, a passively configured remote temperature monitoring can be used, which analyzes the heat radiation reflected by the receiver to the outside.

Claims

claims

1. Method for monitoring a component

- in which the component, as part of a solar installation, receives and converts solar energy by means of a receiver,

- in which by means of a remote monitoring method, in particular a wireless remote monitoring method, the temperature of the receiver of the component is determined, and

- In which, depending on the temperature adjustment or correction of the component is performed.

2. The method of claim 1, wherein the remote monitoring method sends a wirelessly transmitted measurement signal to the receiver and receives a reflected from this also wirelessly transmitted measurement signal, wherein the temperature is determined by comparing the two measurement signals.

3. The method of claim 1 or 2, wherein the remote monitoring method uses infrared rays or microwaves for temperature determination.

4. The method according to claim 2 or 3,

in which the measuring signal from a remote monitoring device reaches the receiver via a mirror which is assigned to the receiver,

- In which the measurement signal from the receiver surface is reflected and reflected back over the associated mirror to be received by the remote monitoring device.

5. The method according to any one of the preceding claims, wherein the temperature of the receiver, in particular in a parabolic trough plant or a concentrator photovoltaic system is determined by punctual measurement at the receiver.

6. The method according to any one of the preceding claims,

in which, in a concentrated photovoltaic system, the representative temperature of a module is determined, the module including a number of mirrors and receivers associated therewith,

- Wherein, by the measurement signal, a surface scan of the module is carried out to determine the temperatures of the receiver, which are arranged in the module.

7. The method according to any one of the preceding claims, wherein, depending on the temperature, the mirrors are tracked by a control the current position of the sun.

8. The method according to any one of the preceding claims, in which using the temperature measurement, defective components are located within a system for repair or replacement.

9. Arrangement for carrying out the method according to one of claims 1 to 8,

- with a component which, as part of a solar installation, receives and converts solar energy with the aid of a receiver,

- With a remote monitoring device which uses wirelessly transmitted measuring signals, the temperature of the receiver of the component determined to perform depending on the temperature adjustment or correction of the component.