Method and device for control of power supplied to equipment to prevent ice formation or snow/ice removal from structural member

FIELD: transport.

SUBSTANCE: group of inventions refers to control devices of supplied electric power in order to prevent ice formation or to remover snow/ice from structural member surface. In the method the supply of power us controlled by means of controller which is operated on the basis of values of physical parameters which are measured by means of transmitters located on structural member and on the basis of preceding measurement data referring to snow or ice conditions. Input data is temperature of structural member, amount of snow/ice on structural member, air temperature, wind velocity, precipitation, speed of structural member and the corresponding vibrations. The above input data is compared to the stored data of preceded measurements by means of controller. After comparison the controller calculates by using the defined algorithm the required power, as well as required values of current load and frequency. Frequency influences the temperature change time constant of structural member surface. Then, controller supplies start or stop signals to power supply equipment. After that, controller modifies the stored data with new data of values of parameters, which are the consequence of current snow/ice state on structural member in compliance with pre-set sequence.

EFFECT: achieving optimum output values of power required to prevent/remove ice/snow from structural member surface.

6 cl, 3 dwg

The technical field to which the invention relates.

This invention relates to method and means for controlling the supply of electrical energy to prevent the formation of ice or snow removal/ice from the surface of the structural element. In fact, the main application of the present invention is intended to remove or prevent the formation of a layer of ice or snow on the blades of the air turbine, although the invention will also find application for blades of aircraft engines, rotors of helicopters and, in particular, in motion, but also stationary outer parts of structures located in open places, such as oil rigs in the Northern regions.

The level of technology

Today there is a large universal need for an energy source that is not harmful to the environment. In connection with this investigation of the source of energy associated with the wind is a very interesting solution. This can cause widespread increase in the use of wind energy as an energy source that is safe for the environment.

Most of the available sources, wind energy is located in areas where climatic conditions are an issue for wind turbines due to the formation of layers of snow or ice on the most important parts of the turbines. This requires a shutdown of the turbines, increasing the cost and reducing the income associated with the installation, it affects the attractiveness of investments in wind energy production. Therefore, significant energy potential may remain unused.

Today, there are some ways to solve the problem of formation of layers of ice and snow on the wind turbines. However, these methods are quite expensive, as well as technically complex, which increases the cost of design and installation.

U.S. patent No. 6612810 describes a wind turbine, in which a thin metal foil is positioned on the screw turbine. The electric current may be passed through the metal foil, which under its influence acts as a heating element and able to melt any snow or ice is present on the blade. The metal foil may be laminated on the surface of the blade or may be fixed on the blade, for example, with adhesive. This patent also addresses the regulation of heating, using a relay, connected to the sensor cold, located on the surface of the blade. Therefore, the sensor only controls the on-off, there is no ability to adjust the flow of current to the metal foil from the energy source. It is very simple the first control mode, which, as it turned out, not suitable for its purpose due to high energy consumption. In addition, water kindled ice flows on the unheated surface and freezes again.

European patent EP-0-983437-B1 also describes the heating of blades for wind turbines. In this patent the production includes conducting electricity fibers placed on internal or external surfaces of the blades, which are used as heating elements for removing snow or ice. The current supplied to the heating elements may be controlled using a temperature controller/energy measuring and monitoring of many parameters, such as weather conditions in the immediate vicinity of the turbine and the temperature of the surface of the blade. Also, the controller may control the current distribution at different heating elements in accordance with the pre-established technique for removing ice from parts of the blades in order to avoid imbalance when, for example, blocks of ice fall from the blades. The management model is used to enable, among other things, feedback to change the control functions based on external conditions. Thus, however, it concerns the functions of the control current distribution on different parts of the blades.

U.S. patent No. 5344696 describes with the heating system for the blades of the aircraft, including layers ongoing electricity material, which is laminated blades. In this system, the current applied to the heating device has a frequency in the range of 50-400 Hz. The system also uses a management system based on the temperature sensors in the blades and on its surface, which are connected to a microprocessor-based controller. The voltage can be adjusted based on the temperature measurements. This is a fairly simple control system that is not able to take into account data obtained practically.

Finally, the nearest patent application Norway No. 20042395 describes a heating system for turbine blades, which uses high-frequency electric current applied to the metal foil surface of the blade. In this application adaptive automatic controller is used to collect data from sensors that measure climatic conditions such as air temperature, wind speed and precipitation. Additionally gather data related to the surface temperature of the blade in the areas of blades, where they are exposed to snow and ice, as well as data from the speed sensors and vibration. The controller determines the current strength and frequency, based on data from sensors, as well as the stored data of previous measurements related to the conditions of snow cover area and icing of the turbine, to control the frequency transformer for optimum power metal foil located on the blades.

A previous publication whereas this prior art. However, the applicant wishes to note that the technology can be improved by elimination of the disadvantages of technology management, because in reality you still have too much energy consumption for deicing.

The invention

Control method, in which the present invention is to solve the above problems, as a method that provides a high level of energy productivity. However, the method is quite easy to use from a technical point of view and is an affordable solution from an economic point of view. The method is also simple and inexpensive to use in the wind turbine.

According to the invention the method is provided by the flow control of electrical energy by means of high frequency alternating current from the equipment to power the heating equipment to prevent ice formation or removing ice or snow from the structural elements, in which control is performed using the controller, which is guided by the input data representing the a values of the physical parameters, measured by sensors located on or in the vicinity of the structural elements, as well as based on stored values of previous data relating to the conditions of snow cover area and icing of the structural element, providing adaptive control method. The method according to this invention differs in that:

current input data relating to the value of the effective surface temperature of the structural element and the values of the following parameters: the amount of snow/ice on the surface of the structural element, air temperature, wind speed, rainfall, speed of the structural element and the vibration of the structural member, the controller compares the stored previous values for these parameters that are registered as a temporary function, and

- using the stored algorithm, the controller calculates, based on the specified relevant input and the previous data, the need for energy transfer and in this case also the current values and frequencies that are required to remove snow/ice from the surface of the structural element, frequency, affecting the time constant of the temperature change of the structural element,

in accordance with the result of the calculation, the controller transmits a signal to start or stop, as well as the external is the second control signal, includes current and frequency, power supply equipment, and

controller replaces the previous data new data values, which are the result of a measurement of current conditions snow cover area/ice on the surface of the structural element according to a predetermined method.

In addition, according to an additional aspect of the invention provided with means for controlling the supply of electrical energy by means of high frequency alternating current from the electricity supplying equipment to the heating equipment to prevent ice formation or removing ice or snow from the structural element, which contains a controller that performs an operation based on input data representing the values of the physical parameters measured by sensors located on or in the vicinity of the structural element, in which the controller is controller of the adaptive type. The tool according to this invention differs in that:

- the controller is configured to compare the current input data that relate to the value of the effective surface temperature of the structural element and the values of the following parameters: the amount of snow/ice on the surface of the structural element, air temperature, wind speed, precipitation of the cages, the speed of the structural element and the vibration of the structural member, with the stored data of the previous values of these same parameters, which are stored as a temporary function, and

the controller is additionally configured to calculate, using a stored algorithm and based on the specified input and the previous data, it is necessary to transmit energy to the heating equipment and in this case also the value of the current strength and frequency required to remove snow/ice from the structural element, frequency, affecting the time constant of the temperature change of the structural element,

the controller is additionally configured to, according to the result of this calculation is to send a signal to start or stop, as well as external control signal, including the current values and the frequency at the power supply equipment, and

- the controller is configured to replace the previous data new data values, which are the result of measurements of current conditions snow cover area/ice on the surface of the structural element according to a predetermined method.

The method and means described herein, provide a technically and economically favorable protection from icing to prevent buildup of snow or ice neotectonic elements for wind turbines, installed in areas with climatic conditions that pose a danger of icing.

Using this method, an optimum use of the existing potential for energy production at any time and, therefore, allows you to make the most of the geographical areas that can be used for cost-effective production of environmentally friendly wind energy, in the long run.

In accordance with the method of this invention, the wind turbine can be operable under critical combinations of temperature, wind speed and precipitation, causing the buildup of snow or ice on the rotating elements of the turbine or the items on which icing may cause harmful static loads.

The method has significant commercial potential, giving rapid growth in emerging industry development sources of air power. Additionally, a large part of the geographical areas with significant wind energy potential is located in areas where climatic conditions are caused by the buildup of snow or ice on critical elements of the turbine. The method solves many of the problems associated with zasnezhennomu or icing wind the new turbines, efficient and economically favorable. Moreover, the method also promotes the growth of value in the development of this industry, among other things, increased inflow of investment required in areas facing risk of snow cover area or icing.

Brief description of drawings

Below is a more detailed description of the present invention, including a detailed overview of the preferred embodiments, with reference to the attached drawings, on which:

Figure 1 shows the cross-section of part of the structural element, in particular a wind turbine blade with metal foil used for heating.

Figure 2 shows a schematic view of the controller used to adjust the flow of electricity on the metal foil, and

Figure 3 is a block diagram showing the control method according to a variant implementation of the invention.

A detailed description of the preferred embodiments

It should be noted that, while the description is based on wind turbines, which must be removed ice, the invention will also find application in other areas, such as the blades of the aircraft, the rotors of helicopters, and other exterior structures, in particular movable structures, for example, reference is made normally on "device" and "e is the dude designs", when the invention is described in more General form. With this in mind, in future wind turbines will be a practical option implementation.

In accordance with the foregoing and by reference to figure 1, the method according to this invention refers to the use of high-frequency electric current for heating the surface 2 of the element 1, which is the object of snow cover area or icing, the value of which is invalid for operation of the turbine. The surface 2 of the element 1, on which the layering of snow or ice formation invalid, provided the conductive material 3, preferably represents a metal foil, which has the form of strips of different lengths attached to the surface 2 as adhesive tape. The tape also provides the necessary protection for the surface 2 against mechanical and chemical influences. The foil can be fixed with the surface 2 with the ability to quickly remove foil during servicing. Through the conductive material 3 (foil) is skipped high-frequency current that is due to local climatic data that are provided by the system to which this method. The equipment ensures that the current is passed through the material 3 surface 2, when there is a danger of formation of snow or ice on the responsible protected element of the Ah. The temperature of the surface increases, preventing the accumulation of snow or ice formation. Moreover, when starting the wind turbine after a nonworking period of removing snow or ice from critical parts will effectively before starting the turbine.

Referring further to figure 2, the device according to the invention mainly contains equipment 11, 13 for the adaptive generation of high-frequency current having the variables current and frequency. Energy equipment can be transmitted from the turbine generator or from the grid 10, which turbine transmits the selected energy. The equipment further comprises a controller 13 for controlling, tracking, and verification of the technological details of the entire system, including sensors 4, 14, 15, 17, 18, 19, necessary for continuous detection of mechanical and climatic conditions at the location of the turbine.

Launching and operating the system automatically on the basis of data on climatic conditions at the location, under the influence of operating conditions, taking into account whether turbine or is preparing to run.

Adaptive automatic controller 13 collects data on climatic conditions from sensors, including temperature 19 air speed 17 wind and precipitation 18.

Additional data collected since the element is in the turbine, which may be the build up of snow or ice, i.e. from the sensor 4 temperature surface sensor 15 of the rotation speed and the vibration sensor 14. On the basis of the sensor data and the previous data relating to the conditions of snow cover area and icing for a given turbine, the controller 13 determines the strength of the current, and frequency for high-frequency current transmitted on the metal foil (heating element) 3, and adjusts the transformer 11 frequency to optimize power metal foil 3.

The controller 13 continuously monitors the presence of snow or ice on exposed parts in accordance with climatic data and data about the work and uses these data in a continuous calculation of the current strength and frequency, which indulge heating element 3.

Through the foil 3 is skipped high-frequency current having a frequency, forcing the current to flow in the surface layer of foil. The current frequency is governed by the system in such a way as to minimize the energy consumption in the system, on the basis of, in particular, the surface temperature of the element, which prevents the accumulation of snow or ice formation. The optimal frequency is calculated using an algorithm that is based on current and previous data. Essentially, the frequency thermal current affected by the temporary Konsta is the temperature change of the surface element so it is possible to determine the frequency, which is "the cheapest" way leads to rapid heating. The time constant surface temperature is influenced, in particular, using the relationship between frequency deviation and the current in the heating element.

System to prevent the formation of ice and/or snow on the device starts and stops automatically, under the influence of information from sensors that transmit data on local climatic and mechanical conditions, on the basis that the current temperature, precipitation and wind speed together with the basic working conditions (rotation speed of the turbine, vibrations, surface temperature) have reported the presence of a layer of snow or ice on the important parts of taking into account the climatic conditions, topography, as well as geographical location of the turbine.

The controller 13 also allows adaptive adjustment of the equipment of thermal radiation (metal foil) 3 on the basis of empirical data concerning problems caused by zasnezhennomu and icing, for turbines installed on the device.

Now refer to figure 3, which presents a block diagram of a control method, according to which the controller 13 works. The algorithm begins in block 30. In block 31 are measured included on the nnye relevant measured parameters, such as the value of the speed of rotation of the turbine ω, wind speed n, the precipitation H (sensor), vibration of turbine blades U/A, as well as surface temperature τ₀the temperature of the blades and air τ₁.

In block 32, all previous settings are saved. The values are automatically updated when a change is detected a specific critical value. This occurs when the value of the current buffered in block 33, is defined as non-saved in block 32. This happens when the detected updated critical in block 35.

In block 33, the current values are compared with the critical values. When the value of the current parameter is greater than or equal to a critical value, the signal is sent for the calculation of appropriate actions in block 34. Otherwise, the action is not triggered.

On the basis of the evaluation unit 34, based on the comparison of the surface temperature with a critical surface temperature in the block 37 and by comparing the current value of the precipitation of critical values of precipitation (number of frost/ice/snow/water) in block 38, if the current value exceeds the critical value, the signal is sent to start the heating unit 39 and the calculation of output values (voltage and frequency) on the I heating equipment in block 40.

If the sensors detect ice/snow/frost in block 36, even if the current values of precipitation and temperature do not exceed critical values, critical values are updated in block 35.

If the values of temperature and precipitation does not exceed the critical values and the sensors also do not detect precipitation, the equipment goes into standby mode.

According to the above method ensures the best possible output values of the energy required to prevent/remove ice/snow with the help of adaptive management, which automatically adapts to the specific climate in the workplace. Thus, energy consumption is reduced to an absolute minimum for each specific installation.

1. The method of controlling the supply of electric energy by means of high frequency alternating current from the equipment (11) for supplying energy to the heat-radiating equipment (3) to prevent the formation of ice or to remove ice or snow from item (1) design, in which the control is performed by the controller (13) based on input data representing the values of the physical parameters measured by the sensors(4, 14, 15, 17, 18, 19), which are located near or close to the item (1) design, also based on previous the latter data, relating to the conditions of snow cover area and icing element (1) design, providing adaptive control method, characterized in that the current input data relating to the value of the effective temperature of the surface element (1) design and the values of the following parameters: amount of ice/snow on the element (1) design of air temperature, wind speed, rainfall, speed element (1) design and vibration element (1) designs are compared in the controller (13) with stored data relating to prior values of these same parameters, which is registered as a time function, and using laid algorithms, the controller (13) calculates, based on the respective input and the previous data, whether the energy supply, as well as the necessary current values and frequency to remove snow/ice from item (1) design, the frequency affects the time constant of the temperature change of the surface element (1) design, in accordance with the result of the calculation, the controller (13) generates a signal to start or stop, as well as the output control signal that includes the current values and frequency equipment (11) for the supply of energy and the controller (13) modifies the previous data with new data, parameter values, which is the tsya consequence of the current state of snow/ice on the element (1) design in accordance with a predetermined sequence.

2. The method according to claim 1, characterized in that the frequency used is in the range 0-1000 kHz.

3. The method according to claim 1, characterized in that the predefined sequence modification of previous data includes all the necessary parameters to detect and prevent/remove ice/snow from the structure.

4. A means of controlling the supply of electrical energy by means of high frequency alternating current from the equipment (11) for supplying energy to the heat-radiating equipment (3) to prevent ice formation or removing ice or snow from item (1) of the structure containing the controller (13)based on input data representing the values of the physical parameters measured by the sensors(4, 14, 15, 17, 18, 19), which are located near or close to the item (1) design, and also based on previous stored data relating to the conditions of snow cover area and icing item (1) design, in which the controller (13) refers to the adaptive type, characterized in that the controller (1) is made with the possibility to compare the current input data relating to the value of the effective temperature of the surface element (1) design and the values of the following parameters: amount of ice/snow on the element (1) design of air temperature, wind speed, precipitation of the Oia precipitation, speed element (1) design and vibration element (1) design with stored data related to the previous values of the same parameters that are registered as a temporary function, and the controller (13) is additionally configured to calculate with the help of in-built algorithm and based on the respective input and the previous data, whether the energy source for a heat-producing equipment (3), and also values of the current strength and frequency required to remove snow/ice from item (1) design, the frequency affects the time constant of the temperature change of the surface element (1) design, the controller (13) is additionally configured to, in accordance with the results of these calculations, to issue a start signal or stop, as well as the output control signal that includes the current values and frequency equipment (11) for the energy supply, and the controller is configured to modify the previous data with new data, parameter values, which are the result of the current state of snow/ice on the element (1) design, in accordance with a predetermined sequence.

5. The tool according to claim 1, characterized in that it is arranged to control supply of electricity to the electrically conductive is Olga, at least the blades of the air turbine.

6. The tool according to claim 4, characterized in that the equipment for power supply is formed by using a transformer with adjustable frequency, receiving energy from an external electrical network (10).