WO2011081548A1

WO2011081548A1 - Actinometer

Info

Publication number: WO2011081548A1
Application number: PCT/RU2009/000752
Authority: WO
Inventors: Виктор Владимирович ЦАРЕВ; Александр Николаевич АЛЕКСЕЕВИЧ; Александр Викторович ГОРДИН
Original assignee: Tsarev Viktor Vladimirovich; Alekseevich Aleksandr Nikolaevich; Gordin Aleksandr Viktorovich
Priority date: 2009-12-30
Filing date: 2009-12-30
Publication date: 2011-07-07

Abstract

The present invention relates to instruments for measuring the intensity of direct solar radiation. The actinometer comprises a sensor with a plate having a receiving surface coated with a heat-absorbing material. A Peltier thermo-electric module is used for converting the thermal energy into electric energy, and is mounted on the sensor body under said plate. The plate is protected by a transparent dome. When heating the monitoring plate, the Peltier thermo-electric module is switched on and the plate is cooled down to a required temperature. Means for measuring the electric current are provided in the form of a measuring unit comprising a control unit, a current regulator, a direct current source, and means for sending to a computer information on the electric current supplied to the thermo-electric module. The actinometer sensor may include a second chamber in which a second receiving plate is protected by a light-reflecting screen, wherein the volumes of both chambers communicate with each other. The technical result is an increase in the measurement precision.

Description

Technical field

The invention relates to devices for measuring the intensity of direct solar radiation by the degree of heating of the absorbing blackened surface and can be used in devices using solar energy, for example, to determine the amount of solar radiation entering the surface of the solar collector.

State of the art

The most known constructions of actinometers described in | bttp: //wvvw.propogodu.ru/alphabet 570].

The basic principle of the actinometer is based on the absorption of incident radiation on a blackened surface and the conversion of its energy into heat. Actinometer is a relative device, because The radiation intensity is judged by various phenomena that accompany heating.

A known sensitive element of the actinometer (Pat. RFL2011953), comprising a housing,

made in the form of a hollow ball of insulating material and a thermocouple battery. The thermocouple battery is installed so that successive thermocouple junctions are fixed at diametrically opposite points on the surface of the ball. Thermoelectrodes pass inside the ball, and the outer surface of the ball is coated with an absorbent coating. Thus, junctions of series-connected segments of insulated wire, such as copper and constantan, passed through holes in a hollow plastic ball, constantly facing the sun with their “hot junctions” and toward the earth with their cold. Regardless of the time of day, 50% of the junctions are in the “hot” and 50% in the “cold” zone, regardless of the angle of contact of the radiant energy, with an inertia of about 1-3 s. This design solves the problem of determining the total amount of solar radiation over a long time and is suitable for meteorological observations. In the above device, thermocouples are used as sensors. Thermocouples cover the entire spectrum of solar radiation, but require complex temperature compensation and manual calibration, which makes sensors based on them very expensive. Another significant drawback of thermocouples is the problem of heat removal before the next measurement, therefore, in order to achieve a heat balance, the intervals between measurements should be sufficiently large.

Thermoelectric actinometers, for example, the Savinov-Yanishevsky thermoelectric actinometer, the design of which is described in [http://www.propogodu.ru/alphabet/570], are widely used.

The receiving part is a thin silver disk blackened from the outside, the central junctions of thermocouples consisting of zigzag-connected strips of manganin and constantan (the so-called Savinov asterisk) are glued to the inside of it. Peripheral junctions are glued to the copper ring in the housing. When sun rays fall on the receiving surface, the central junctions heat up, while the peripheral ones are shaded; the result is a thermoelectric current proportional to the temperature difference between the central and peripheral junctions, which in turn is proportional to the measured radiation flux.

This design solves the problem of determining the total amount of solar radiation over a long time and is suitable for meteorological observations. However, if it is necessary to determine the amount of solar energy supplied to a fixed surface, for example, the surface of a solar collector, the measurement results do not correspond to the amount of solar radiation that entered the flat surface of the collector. This is due to the fact that when determining the amount of solar radiation incident on the solar panel, it should be borne in mind that the solar panel is installed at a certain fixed angle to the surface of the earth. Therefore, the amount of solar radiation entering the surface of the collector depends not only on the intensity of solar radiation, but also on the position of the sun.

To obtain information on the amount of solar energy incident on a flat inclined surface (for example, per day) using existing instruments, in addition to the traditional actinometer, which measures the intensity of solar radiation, at least a device that determines the position of the sun in the sky to calculate the projection is required plane at every moment of measurement. In addition, different mathematical models can be used to process the results and calculate the energy incident on the inclined surface, which can give inconsistent results. Object of the invention

The objective of the present invention is to provide an actinometer design for direct year-round monitoring of solar radiation entering a flat surface mounted in a fixed position at an angle to the earth’s surface and expanding the arsenal of devices for measuring total solar radiation arriving at a flat inclined surface.

SUMMARY OF THE INVENTION

The problem is solved in that in an actinometer containing a sensor with a plate, the receiving surface of which is coated with a heat-absorbing coating, means for converting the thermal energy of solar radiation absorbed by the receiving surface into electrical energy connected to the specified plate, and means for measuring the electric current proportional to the incident on the receiving surface of the radiant energy, in accordance with the invention, means for converting thermal energy into electrical energy include a thermal module elte mounted in the sensor housing under a blackened plate, a heat conductor in contact with one of its surfaces with the bottom surface of the plate, and with its other surface with a Peltier thermal module, with the first thermal sensor installed in the groove between the test conductor and the plate, and the working surface of the plate protected by a transparent dome fixed in the indicated case.

The essence of the device’s action is the controlled selection of heat from the sun on the blackened copper plate of the sensor. When the control plate is heated, the Peltier thermal module is turned on and cools it to the required temperature, i.e. removes heat and discharges through the radiator into the atmosphere. Since the amount of heat pumped by the thermal module is proportional to the amount of electricity passed through it, then by calculating the amount of this electricity, we will also get the amount of solar energy incident on the plate.

The thermal modules themselves, using the Peltier effect, are widely known and are mass-produced. However, the use of such thermal modules in actinometers is unknown to the authors.

The use of Peltier thermal modules allows us to expand the range of used technical means for recording solar radiation. The structural features of these elements make it possible to fix the receiving plate at the same angle relative to the earth as the surface of the solar collector. This provides a direct and accurate measurement of the flux of solar radiation incident on the surface of the solar collector. The transparent dome protects the actinometer sensor from atmospheric influences, which allows the device to be used year-round. In addition, an actinometer based on Peltier thermomodules can be made compact enough, and complex mathematical models are not required to interpret the measurement results.

It is advisable that the actinometer sensor housing includes a second camera of almost identical design, differing only in that the second receiving plate is protected by a reflective screen mounted in the specified housing, and the inner space of both cameras communicates between by myself. This reduces the temperature dependence and improves the accuracy of the measurement. The amount of solar radiation in this design is determined by the difference in currents passing through thermocouples.

In the event that a single-chamber version of the actinometer sensor is used, it is advisable to install an additional temperature sensor on its case from the inside. In this case, the amount of solar energy is determined by the amount of electricity supplied to the thermocouple, necessary to align the readings of the temperature sensors.

When using the single-chamber version of the actinometer sensor, it is advisable that the means for measuring the electric current are made in the form of a measuring unit, which is electrically connected to the temperature sensors and the thermal module. The measuring unit includes a control unit, which receives the signals of the temperature sensors. The control unit generates a control signal by which the electric current supplied from the direct current source to the thermal module is regulated to equalize the readings of the thermal sensors. The measuring unit is equipped with an interface for communication with a computer.

It is advisable that the actinometer sensor case be equipped with a heat sink in the form of a radiator located on the "hot" side of the thermal module.

To improve thermal insulation and improve accuracy, it is advisable that a thermal insulation gasket is installed between the thermal module and the housing.

It is advisable that the plate and the wire conductor were made of copper.

To further reduce the temperature dependence, it is advisable that the interior of the housing be evacuated.

When using the two-chamber version of the actinometer sensor, the means for measuring the electric current supplied to these thermal modules can be made in the form of a measuring unit, comprising a first controlled current controller electrically connected to the first temperature sensor and the first thermal module, and a second controlled current controller connected to the second thermal sensor and the second thermal module. A DC power supply is electrically connected to the first and second controlled current regulators. The differential current meter is connected between the first and second thermal modules and is connected via an converter to the interface for communication with a computer.

Brief Description of the Drawings The invention is illustrated by drawings, in which

Figure 1 depicts a single chamber actinometer sensor, made in accordance with the invention, in cross section;

Figure 2 depicts a block diagram of an actinometer with a single-chamber sensor, made in accordance with the invention;

I

Fig. 3 depicts a two-chamber actinometer sensor, made in accordance with the invention, in cross section;

Figure 4 depicts a block diagram of an actinometer with a two-chamber sensor, made in accordance with the invention;

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, the actinometer sensor includes a molded plastic case 1 into which a copper heat conductor 2 is integrated at the manufacturing stage. A copper plate 3 with a heat-absorbing coating is attached to the heat conductor 2. The heat-absorbing coating is a layer of soot, black ink or the like. A temperature sensor 4 is placed in the groove between the plate 3 and the heat conductor 2. For example, a thermistor can be used as a temperature sensor. The space in front of the plate 3 is closed by a transparent, for example, glass dome 5, which is hermetically mounted in a special recess on the housing 1. In order to eliminate the influence of heat loss through the dome 5 and the walls of the housing 1, the interior of the sensor is evacuated. In the lower part of the housing 1 between the heat conductor 2 and a copper fin heat sink 6, a thermal module 7 is installed. Before installation, a special thermal paste is applied to the working surfaces of the thermal module 7, which ensures reliable heat transfer at the contact points. The heat sink (radiator) 6 is attached to the housing 1 with screws made of a material with high thermal resistance (for example, plastic). The heat sink can also be made of copper. In order to exclude the contact of the thermal module 7 with the outside air between the body 1 and the radiator 6, a heat-insulating gasket 8 is laid. Also on the body 1 is a second thermal sensor 4 and a cable connector (not shown). The measurements are carried out in accordance with the diagram in figure 2. As indicated above, the actinometer sensor has two temperature sensors: the first temperature sensor 4 in figure 1 is for measuring the temperature of the plate and the second, not shown in figure 1, the temperature sensor is for measuring the temperature of the housing 1 of the sensor. The signals from the first and second temperature sensors 4 are fed to the comparator of the control unit 9 (Fig. 2), which controls the current regulator 10. The measurement unit also includes a direct current source 1, electrically connected to the thermal module 7 through the current regulator 10 (Fig. 1). Information about the electric current supplied to the thermal module 7 is recorded by the current sensor and through the converter 12 and the interface 13 is fed to a computer (not shown in Fig.).

As shown in FIG. 3, the actinometer sensor may also have a two-chamber design. In this case, the sensor housing 16 includes a first camera 17, identical to the design described above, and a second camera 18, in which, instead of a transparent glass dome 19, a reflective screen 20 is mounted, fixed in the housing 16. The inner space of the camera 17 and the camera 18 communicate with each other , for example, using channel 21. On the “hot” side of the thermal modules 22,23, as in the described single-chamber design, a heat sink is placed.

The block diagram of the actinometer, which uses a two-chamber sensor, is shown in Fig.4. As can be seen from figure 4, the temperature sensors 26, 27 installed in the chambers 17, 18 are electrically connected with controlled current regulators 28, 29, respectively. Controlled current regulators 28, 29 are electrically connected to thermoelectric modules 22, 23, respectively. Current regulators 28, 29 are powered from a DC source 30. The differential current meter 31 is connected between the first and second thermal modules 22, 23 and is connected via an converter 32 to an interface 33 for communication with a computer (not shown in Fig.). Actinometer with a single-chamber sensor (Fig.1,2) works as follows.

In the absence of solar radiation, the temperature of the plate 3 is equal to the temperature of the housing 1, i.e. outdoor temperature.

The signals from the temperature sensors are fed to the comparator of the control unit 9 controlling the current regulator 10. When the signals of the temperature sensors are equal, the current in the power circuit of the thermal module 7 is equal to zero. When the solar radiation sensor enters the plate 3, it heats up, which is detected by the temperature sensor 4. And if the temperature sensor 4 installed on the plate 3 detects a temperature increase, the control unit 9 through the current regulator 10 supplies current from the power source 11 to the thermal module 7, which starts heat removal from plate 3 of the sensor.

Information from the current sensor through the Converter 12 and the interface 13 enters the computer, where it is processed and recorded. As the plate 3 cools, the current through the thermal module 7 decreases and, when the readings of the temperature sensors are aligned, the cooling process stabilizes. With a decrease in the intensity of solar radiation, when the thermal sensor mounted on the plate 3 detects a decrease in temperature relative to the temperature of the housing 1 fixed by the second thermal sensor, the current through the thermal module 7 begins to decrease until the heat balance is restored again. With increasing intensity of solar radiation, the process repeats.

The operation of the actinometer, in which the two-chamber design of the sensor is used, differs from the operation of the actinometer with a single-chamber sensor only in that the amount of solar radiation is determined by the difference in the currents passing through the thermocouples. Industrial applicability

The described actinometer can be made from commercially available standard elements and conventional structural materials.

Claims

CLAIM

An actinometer, containing a sensor with a plate, the receiving surface of which is coated with a heat-absorbing coating, means for converting the thermal energy of solar radiation absorbed by the receiving surface into electrical energy connected to the specified plate, and means for measuring the electric current proportional to the radiant energy incident on the receiving surface, The reason is that the means for converting thermal energy into electrical energy include a Pelt thermal module installed in the sensor housing under the specified plate, a heat conductor in contact with one of its surfaces with the lower surface of the specified plate, and with its other surface with the Peltier thermal module, the first thermal sensor installed in the groove between the heat conductor and the specified plate, and the working surface of the plate is protected by a transparent dome fixed in the specified housing.

The actinometer according to claim 1, with the fact that the actinometer sensor housing includes a second chamber, in which a second Peltier thermal module is installed under the second plate, a second heat conductor in contact with one surface with the bottom surface of the second plate and its other surface with the indicated second Peltier thermal module, wherein an additional thermal sensor is installed in the groove between the second heat conductor and the second plate, the working surface of the plate is protected by a reflective screen fixed in the specified housing, and the internal space of both cameras communicates with each other.

The actinometer according to claim 1, with the fact that a second temperature sensor is installed on the housing from its inner side. Actinometer containing a sensor with a plate, the receiving surface of which is coated with a heat-absorbing coating, means for converting the thermal energy of solar radiation absorbed by the receiving surface into electrical energy, including a Peltier thermal module connected to the specified plate, mounted in the sensor housing under the specified plate, a heat conductor in contact one surface with the bottom surface of the specified plate, and the other with its surface with a Peltier thermal module, and in the groove between the heat The first temperature sensor is installed by the farmer and the specified plate, the second temperature sensor is installed on the case on its inside, and the working surface of the plate is protected by a transparent dome fixed in the specified case and means for measuring the electric current proportional to the radiant energy incident on the receiving surface, about t and h and the fact that the indicated means for measuring electric current are implemented in the form of a measuring unit, electrically connected to temperature sensors and a thermal module, including a control unit The signal to which the signals from the temperature sensors are supplied, a current regulator controlled by the control unit, a direct current source electrically connected to the thermal module through the specified current controller, and means for transmitting information about the electric current supplied to the thermal module to the computer.

Actinometer, including a first chamber containing a sensor with a plate, the receiving surface of which is coated with a heat-absorbing coating, means for converting the thermal energy of solar radiation absorbed by the receiving surface into electrical energy, including a Peltier thermal module installed in the sensor housing under the specified plate, a heat conductor in contact with one of its surface with the bottom surface of the specified plate, and its other surface with a Peltier thermal module, and in the groove between the heat conductor and said first plate mounted thermo sensor and Rybonaya surface mp Stina protected transparent dome fixed in said housing, a second chamber in which a second a second Peltier thermal module is installed in the receiving plate, a second thermal conductor in contact with one of its surfaces with the lower surface of the second plate and the other with its surface with the specified second Peltier thermal module, with an additional temperature sensor installed in the groove between the second heat conductor and the second receiving plate, the working surface of the second receiving plate is protected a reflective screen mounted in the specified case, and the inner space of both cameras communicates with each other, and means for measuring The electric current supplied to the thermal modules is not affected by the fact that the means for measuring the electric current supplied to these thermal modules are made in the form of a measuring unit, including a first controlled current regulator, electrically connected to the first a thermal sensor, and a first thermal module, and a second controlled current regulator associated with the second thermal sensor and a second thermal module, a DC power supply electrically connected to the first and second controlled current regulators, a differential meter current connected between the first and second thermal modules and through a converter connected to the interface for communication with a computer.

Actinometer sensor with a plate, the receiving surface of which is coated with a heat-absorbing coating, means for converting thermal energy into electrical energy, including a Pelt thermal module installed in the sensor housing under the specified plate, a heat conductor in contact with one of its surfaces with the lower surface of the specified plate, and the other with its surface with the thermal module Peltier, with the fact that the specified body is equipped with a heat sink in the form of a radiator located on the "hot" side of the thermal module.

The actinometer sensor according to claim 6, with the fact that a thermal insulation gasket is installed between the thermal module and the housing The actinometer sensor according to claim 6, characterized in that said plate is made of copper.

The actinometer sensor according to claim 6, characterized in that the heat conductor is made of copper.