KR20120119181A - Cooling control system of solar power plant using optical fiber sensor - Google Patents

Abstract

PURPOSE: A cooling management system of a solar energy generating apparatus using an optical fiber sensor is provided to attach an optical fiber sensor to a solar energy module and to measure temperature of the solar energy module. CONSTITUTION: A temperature detection unit(20) detects temperature of a solar cell module through an optical fiber sensor. The optical fiber sensor is contacted with the solar cell module. A local unit(30) generates information according to an output signal of the temperature detection unit. The local unit transmits the generated information. A cooling unit cools the solar cell module by control of the local unit. A main server(70) collects the information of the local unit through a communication network. [Reference numerals] (20) Temperature detection unit; (35) Local controlling unit; (37) Communication unit; (50) Cooling fluid supplying unit; (60) Relay terminal; (70) Main server; (80) User terminal; (AA) Network

Description

Cooling control system of solar power plant using optical fiber sensor

The present invention relates to a cooling management system of a photovoltaic device using an optical fiber sensor, and more particularly, to monitor the temperature of a solar cell module by directly measuring a temperature of the solar cell module by attaching an optical fiber sensor to the solar cell module. At the same time, the present invention relates to a cooling management system of a photovoltaic device capable of appropriately cooling a solar cell module to improve power generation efficiency.

The solar cell converts solar photons into electrical energy using the properties of semiconductors. It is an energy source that is rich in energy resources and has no problems with environmental pollution. It is attracting attention as.

These solar cells are the smallest unit that generates electricity by using solar light, and the solar cell module is connected to a plurality of solar cells in series and parallel to obtain proper voltage and current, and then compressed together with filler and glass to protect from the external environment. It is manufactured in the form of a module and installed inclined toward the southern sky in the northern hemisphere to receive a lot of sun light.

However, the conversion efficiency of the solar cell is 10-20%, and the main reason for the low conversion efficiency is that the solar cell does not convert all light into electricity, thereby converting light energy that is not converted into electrical energy into heat ( As a result, the loss accounts for about 60% of the total loss.) The temperature of the solar cell module increases.

In the solar cell module, the output decreases as the temperature rises. When the power generation efficiency at 25 ° C. is 100%, the output decreases by 0.45 to 0.55% each time the temperature rises by 1 ° C.

In other words, the temperature and voltage of the solar cell is inversely proportional, so as the temperature rises, the voltage decreases and the power generation output falls. Therefore, the hot summer generation output is lower than the solar radiation. In addition, the solar cell deteriorates due to the temperature rise, and the power generation output decreases as time passes. In order to prevent this, by planting the grass or spaced away by applying the air-cooling formula by the natural wind, the temperature is lowered, but the temperature saving effect is insignificant.

Korean Patent Laid-Open Publication No. 2006-0095903 discloses a solar cell cooling system. The disclosed solar cell cooling system is installed around an outer circumferential surface of the light collecting portion to cool heat accumulated in the light collecting portion, and a plurality of sprays spraying cooling water toward the front and rear surfaces of the light collecting portion corresponding to left and right sides of one side surface. An exothermic cooling unit including a nozzle, a cooling water supply pipe for supplying cold water into the exothermic cooling unit, and a solar cell temperature sensor measuring a temperature accumulated in the solar cell of the light collecting unit.

However, although the resistance temperature sensor is used as the solar cell temperature sensor in the cooling system, the resistance temperature sensor has high nonuniformity because the temperature must be measured by a change amount of a parameter called electrical resistance, and the nonlinearity of the output signal is outstanding. As a result, it is exposed to the external environment, resulting in shortage due to corrosion and moisture and short lifespan of about 2 to 4 years.

The present invention has been made to improve the above problems, by measuring the temperature of the solar cell module precisely using the optical fiber sensor that detects the amount of temperature change in the transition of the wavelength of the photovoltaic device having stability from corrosion and moisture The purpose is to provide a cooling management system.

Another object of the present invention is to provide a cooling management system of a photovoltaic device that can detect the amount of solar radiation falling on the solar cell module to monitor the amount of reduction in power generation output according to temperature change compared to the amount of solar radiation.

The cooling management system of the photovoltaic device of the present invention for achieving the above object comprises a temperature detection unit for detecting the temperature of the solar cell module through an optical fiber sensor installed to contact the solar cell module; A local unit that receives the signal output from the temperature detector and generates information and wirelessly transmits the generated information; Cooling means for cooling the solar cell module under control of the local unit; And a main server collecting information transmitted from the local unit through a communication network.

And a solar radiation detector for detecting an amount of solar radiation falling on the solar cell module and outputting a signal to the local unit so as to check an amount of change in power generation output generated from the solar cell module according to a change in temperature relative to solar radiation. It is done.

The cooling means is provided with a cooling jacket coupled to the rear surface of the support frame for supporting the solar cell module to form a cooling space, and a cooling fluid supply for supplying a cooling fluid to the cooling space, the cooling fluid supply is the cooling A heat exchanger connected to a jacket and a fluid supply line and having a blower fan installed therein, an evaporator installed inside the heat exchanger, a refrigerant flowing therein, a compressor for absorbing latent heat of evaporation from the evaporator and compressing the refrigerant evaporated, And a condenser valve disposed between the condenser and the evaporator to condense the refrigerant condensed by the condenser.

According to claim 3, The cooling fluid supply unit is connected to the fluid supply line further comprises an underground air supply means for supplying the underground air to the cooling jacket, the underground air supply means is buried underground and a plurality of side A suction pipe having a vent hole formed therein, a connection pipe connecting the suction pipe and the fluid supply line, a three-way valve installed at a connection portion of the connection pipe and the fluid supply line to switch a flow path, and installed at the connection pipe. It characterized in that it comprises a blower for sucking the underground air.

As described above, according to the present invention, by measuring the temperature of the solar cell module by attaching an optical fiber sensor for detecting the temperature change by the transition of the wavelength to the solar cell module, accurate measurement is possible and has stability from corrosion and moisture.

In addition, it is possible to prevent the reduction of the output of the solar cell module due to the temperature rise by appropriately cooling the solar cell module by measuring and monitoring the temperature of the solar cell module in real time.

In addition, it is possible to detect the amount of solar radiation falling on the solar cell module can predict the amount of reduction in power generation output according to the temperature change compared to the amount of solar radiation. Therefore, the importance of the cooling management system of the solar cell module can be highlighted.

1 is a block diagram of a cooling management system according to an embodiment of the present invention,
2 is a convex diagram showing a temperature detection unit of the cooling management system of FIG.
3 is a configuration diagram schematically showing a configuration of cooling means of the cooling management system of FIG. 1,
Figure 4 is a schematic diagram showing the configuration of the cooling means of the cooling management system according to another embodiment of the present invention,
5 is a block diagram of a cooling management system of a cooling management system according to another embodiment of the present invention.

Hereinafter, a cooling management system of a photovoltaic device according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

1 to 3, the photovoltaic device has a structure in which a plurality of solar cell modules 5 are arrayed in the support frame 10. Although not shown, the support frame 10 may be installed to be spaced apart from the ground by a support. The support frame 10 may be configured to be fixed to the support or to be tracked to move in accordance with the direction and altitude of the sun.

The cooling management system of the photovoltaic device of the present invention includes a temperature detecting unit 20, a local unit 30, cooling means, and a main server 70.

The temperature detector 20 detects the temperature of the solar cell module 5. As shown in FIG. 2, the temperature detector 20 includes a light source 21, a coupler 23, an optical fiber sensor 25, and a light detector 27 that receives light reflected from the optical fiber sensor 25. . The optical signal detected by the photodetector 27 is output to the local controller 53.

As the light source 21, a broadband light source can be used. In addition, a photo-multiplication tube (PMT) may be used as the photodetector 27. The optical multiplier converts the input optical signal into an electrical signal and sends it to the amplifier.

The optical fiber sensor 25 is attached to the front or rear of the solar cell module 5 to directly measure the temperature of the solar cell module 5. The optical fiber sensor 25 is attached to the solar cell module 5 by an adhesive such as epoxy. The optical fiber sensor 25 is connected to the light source 21 by a cable.

In the present invention, the optical fiber sensor 25 is an optical fiber Bragg grating sensor. It is a sensor that uses the characteristic that the wavelength of light reflected from each grating is changed according to the change of external conditions such as temperature and intensity after engraving Bragg grating on the optical fiber according to a certain length. That is, it has the characteristic of reflecting only the wavelength which satisfy | fills Bragg condition, and transmitting the other wavelength as it is. As the ambient temperature of the grating changes, the refractive index or length of the optical fiber changes, resulting in a shift in the wavelength of the reflected light. Therefore, by detecting the amount of movement of the wavelength reflected from the optical fiber sensor 25, the photodetector 27 can detect the temperature. Thus, the change of the lattice spacing, that is, the strain rate, is derived from the shift of the wavelength. Since the strain is a function of temperature, it is possible to calculate the temperature of the solar cell module 5 by the strain calculated from the movement of the reflected wavelength.

The local unit 30 receives the signal output from the temperature detector 20, generates information, and wirelessly transmits the generated information. The local unit 30 includes a local control unit 35 and a communication unit 37.

The local controller 35 calculates the temperature of the solar cell module 5 by the change of the lattice spacing, that is, the strain rate, from the shift amount of the wavelength reflected by the optical fiber sensor 25 detected by the photodetector 27. The calculated temperature is transmitted wirelessly through the communication unit 37. The communication unit 37 transmits the operation state information to the relay terminal 60 using a wireless communication method such as Zigbee.

The relay terminal 60 receives the signal transmitted from the local unit 30 and transmits the signal to the main server 70 through the network. In this case, the wired / wireless network such as the Internet is applied.

The main server 70 collects information transmitted from the local unit 30 through a communication network. The main server 70 collects the operation state information and the power production information transmitted through the relay terminal 60 from the local unit 30 and stores it in the database 75. For example, it collects and stores information such as temperature, power generation status and output change amount of solar cell module. In addition, the collected information may be output through a display device such as a monitor. In addition, the operation state information together with the main server 70 may be transmitted to the user terminal 80, such as a mobile phone or PDA of the registered administrator.

And when the abnormal operation state information, for example, it is determined that the temperature detected by the temperature detector 20 exceeds the set allowable temperature, it is possible to send the alarm information to the main server 70 or the user terminal 80.

On the other hand, when the temperature of the solar cell module 5 detected by the temperature detector 20 exceeds the set temperature, the local unit 30 operates the cooling means to lower the temperature of the solar cell module 5. The cooling means is coupled to the rear surface of the support frame 10 for supporting the solar cell module 5, the cooling jacket 40 to form a cooling space 43 and the cooling for supplying a cooling fluid to the cooling space 43 The fluid supply part 50 is provided.

In the illustrated example, the cooling jacket 40 has a U-shaped cover structure with an open top. The cooling jacket 40 is coupled to the lower portion of the support frame 10 having a structure in which the lower portion is open to form a cooling space 43 together with the support frame 10. Unlike shown, the cooling jacket 40 may be formed in a cylindrical shape having a cooling space sealed therein.

The cooling fluid supply unit 50 is connected to the cooling jacket 40 and the fluid supply line 47, and has a heat exchange tank 51 having a blowing fan installed therein, and an evaporator installed inside the heat exchange tank 51 and in which a refrigerant flows. 53, a compressor 55 for absorbing latent heat of evaporation from the evaporator 53 and compressing the evaporated refrigerant, a condenser 57 for condensing the refrigerant in the gaseous phase compressed by the compressor 55, and the condenser. A throttling valve 59 is provided between the 57 and the evaporator 53 to throttle the refrigerant condensed by the condenser 57.

The cooling fluid supply unit 50 supplies the cooling fluid heat-exchanged with the refrigerant in the heat exchange tank 51 to the cooling space 43 to cool the solar cell module 5. Air is used as the cooling fluid, but water may be applied.

The cooling fluid supply unit may further include underground air supply means connected to the fluid supply line 47 to supply the underground air to the cooling space 43 as shown in FIG. 4. Here, the underground air can cool the solar cell module by supplying the underground air of about 15 ° C. per year by the underground air supply means.

A suction pipe 93 buried underground by underground air supply means, a connection pipe 90 connecting the suction pipe 93 and the fluid supply line 47, and a connection between the connection pipe 90 and the fluid supply line 47. It is provided with a three-way valve (97) installed at the site to switch the flow path, and a blower (91) installed in the connecting pipe (90) for sucking underground air.

The suction pipe 93 extends underground through the soil layer from the ground to suck underground air from the porous rock layer in the base, and a plurality of vent holes for suction of air are formed on the side corresponding to the rock layer. As the blower 91 is driven, underground air at about 15 ° C. is sucked through the vent of the suction pipe 93 and then blown to the fluid supply line 47. The blown underground air is injected into the cooling space 43 of the cooling jacket to cool the solar cell module 5.

The underground air is selectively injected into the cooling space 43 together with the air cooled in the heat exchange tank 51. That is, when the solar cell module 5 can be sufficiently cooled by only underground air, the solar cell module 5 is cooled by using underground air. When the solar cell module 5 cannot be sufficiently cooled by only underground air, the solar cell module 5 is cooled by using air cooled in the heat exchange tank 51. In addition, the underground air may be introduced into the cooling space together with the air cooled in the heat exchange tank 51 to cool the solar cell module 5. The above-described operation can be appropriately controlled by the local control unit.

On the other hand, Figure 5 shows a cooling management system of a photovoltaic device according to another embodiment of the present invention. 5 is further provided with the solar radiation detection unit in the embodiment of FIG.

The solar radiation detector 100 detects the solar radiation falling on the solar cell module 5 and outputs a signal to the local unit 30. The solar radiation detector 100 is composed of an solar radiation sensor. The solar radiation sensor may be installed in the support frame 10. Photodiode can be used as the solar radiation sensor. Photodiode is a semiconductor diode that generates a photocurrent when light is irradiated, and measures the amount of insolation by using the characteristic that the current increases with the amount of light.

The solar radiation detector 100 detects the amount of solar radiation falling on the solar cell module 5 in real time, and checks the amount of reduction in power generation output according to the temperature change compared to the detected solar radiation amount. Therefore, it is possible to predict the power generation output that can be reduced by preventing the temperature rise of the solar cell module 5, and the output reduction can be prevented by compensating the power generation output that can be reduced by the operation of the cooling system of the present invention. In this way, the amount of solar radiation, temperature, the expected decrease in power generation output according to the temperature rise, power generation status, output change amount due to the operation of the cooling system is displayed through the output device of the main server 70 or the user terminal 80 and Is monitored.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention.

Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

5: solar cell module 10: support frame
20: temperature detector 30: local unit
40: cooling jacket 43: cooling space
50: cooling fluid supply unit 70: main server
80: user terminal 100: solar radiation detection unit

Claims (4)

A temperature detector detecting a temperature of the solar cell module through an optical fiber sensor installed to be in contact with the solar cell module;
A local unit that receives the signal output from the temperature detector and generates information and wirelessly transmits the generated information;
Cooling means for cooling the solar cell module under control of the local unit;
And a main server collecting information transmitted from the local unit through a communication network. The solar cell apparatus of claim 1, further comprising: an insolation detection unit configured to detect an insolation amount of the solar cell module and to output a signal to the local unit to check an amount of change in power generation output generated from the solar cell module according to a change in temperature relative to insolation amount; Cooling management system of the photovoltaic device using the optical fiber sensor, characterized in that it further comprises. According to claim 1, The cooling means has a cooling jacket coupled to the rear surface of the support frame for supporting the solar cell module to form a cooling space, and a cooling fluid supply for supplying a cooling fluid to the cooling space,
The cooling fluid supply unit is connected to the cooling jacket and the fluid supply line, a heat exchange tank having a blower fan installed therein, an evaporator installed inside the heat exchange tank, in which a refrigerant flows, and absorbing the latent heat of evaporation from the evaporator to compress the evaporated refrigerant. And a condenser for condensing the refrigerant in the gaseous phase compressed by the compressor, and an throttling valve installed between the condenser and the evaporator to throttle the refrigerant condensed by the condenser. Cooling management system of photovoltaic device using sensor. According to claim 3, The cooling fluid supply unit is connected to the fluid supply line further comprises an underground air supply means for supplying underground air to the cooling jacket,
The underground air supply means is buried in the basement and a plurality of air vents formed in the side of the suction pipe, the connection pipe connecting the suction pipe and the fluid supply line, the connection pipe and the fluid supply line is installed on the connection portion of the flow path Cooling management system of the photovoltaic device using the optical fiber sensor, characterized in that it comprises a three-way valve for switching the, and a blower installed in the connection pipe for sucking the underground air.

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