RU2233018C1 - Method and device for deicing ground-based parabolic antenna - Google Patents

Abstract

FIELD: deicing systems; heat control of ground-based parabolic antennas.

SUBSTANCE: bottom part of reflector is fanned with hot air flowing in direction orthogonal to its rear surface. Hot-air fan is mounted in bottom part of reflector so that air flow is passed in direction orthogonal to its rear surface. Power voltage regulator newly introduced in switching unit of control system is coupled with temperature transducers.

EFFECT: simplified design; enhanced effectiveness of deicing process.

3 cl, 2 dwg

Description

The present invention relates to anti-icing and thermal stabilization systems of terrestrial parabolic antennas.

The known “De-icing device for a radar system” (Inventions of the world. Review journal. M., 1993, issue 106, No. 8. Waveguides, resonators, antennas. P. 10).

The device consists of a bundle of wires located on the screen, placed in front of the antenna opening and connected by a combined series-parallel connection to the branch terminals of the power source so that a heating current passes through each of them. This system provides a double protective effect: from the counteraction of EMF induction (for example, a nuclear electromagnetic pulse) and from icing of the antenna.

The disadvantage of this analogue is that the electric heater does not provide a thermostabilizing effect on the design of the antenna as a whole, since it does not have the corresponding convective connections between the individual elements.

The thermally stabilizing system of the parabolic antenna of the Japanese telescope is also known (B. Polyak B.C. and other Precision Designs of Mirror Radio Telescopes. Riga. Knowledge. 1990. S. 135-137, Fig. 4.49).

The analogue contains a reflector (reflective shield of the mirror), mounted on the truss frame, a heat-insulating casing, forming an air cavity in which the frame, fan, temperature sensors are located. The device is designed for thermal stabilization of the reflector and frame in variable climatic conditions.

The device operates as follows.

When the antenna is exposed to various climatic factors, when the temperature gradient increases along the frame in the radial direction, for example, approaches the extreme values of the range ± 0.5 ° C / m, the fan turns on, while the air circulating in the closed air cavity equalizes the temperature frame field.

The disadvantage of this device is that it does not provide a sufficient degree of uniformity of thermal connection of various sections of the structure by blowing them with air flow. Near the fan, sections of the structure are blown with air at a greater speed than those removed from it, and therefore the temperature of the former is provided much closer to the averaged air temperature compared to the temperature of the remote sections. In this case, the heat transfer coefficients between the air flow and the blown surface areas are significantly different from each other (they decrease in the direction of the flow with a simultaneous decrease in the temperature difference between the air and the blown surface areas). This leads to a decrease in the effectiveness of anti-icing effects and thermal stabilization in the system.

As a prototype, “The method of de-icing a terrestrial parabolic antenna and a device for its implementation” was selected, patent of the Russian Federation No. 2192074, priority from 12/18/2000, cl. H 01 Q 1/02.

The prototype includes a terrestrial parabolic antenna reflector mounted on a frame with radial stiffeners, a thermal cover mounted on a reflector frame and forming lower and upper air cavities separated by partitions with the formation of air passages along the reflector periphery and a passage in the central part of the reflector, fan heaters installed in parallel with central air passage, switch unit for controlling fan heaters, temperature sensors.

In the prototype, a method for de-icing a terrestrial parabolic antenna was implemented, including blowing with heated air under a thermal cover of the back of the reflector with its skeleton, namely, heated air is fed from the central part of the reflector down to its periphery, which is then sent to the upper part of the reflector.

The implementation features of the method consist in the fact that the air cavity for blowing the reflector and the frame is divided by partitions into the lower and upper cavities, which are interconnected by air passages along the periphery of the reflector, as well as in its central part, the main fan heater with the air flow direction lower cavity; as partitions used radial stiffness elements of the reflector frame, which are made airtight; in the air passage made in the central part of the reflector, additional fan heaters are installed in parallel with the main one, moreover, with the direction of air flows to sectors formed by radial stiffeners of the reflector frame.

The disadvantage of the prototype lies in its complicated design, which requires replacing radial stiffeners in a conventional antenna (making them airtight, while they are made with evenly spaced holes to reduce mass and temperature deformation to ensure their required stiffness), to separate the air cavity of the airflow of the reflector and the frame with partitions on the lower and upper cavities, connect them together with air passages along the periphery of the reflector, as well as in its central part, to take an air passage in the center of the reflector with the installation of a fan heater in it.

Another disadvantage of the prototype is that the direction of blowing with the warmest air is carried out from the central part of the reflector with a downward direction to the lower part of its periphery, which creates additional resistance to the flow due to the natural tendency of the air to rise upward, as the most heated. This, on the one hand, increases the resistance to the generated air flow, on the other hand, the most heated air acts primarily on the central part of the reflector, and not on the lower, where icing forms. As a consequence of this, the anti-icing efficiency of the prototype is reduced.

In addition, the commutator unit of the control system does not provide voltage control of fan heaters (fans and electric heaters themselves) depending on the temperature sensors, which leads to unnecessary energy and resource consumption of fan heaters at ambient temperatures close to 0 ° C, when anti-icing of the reflector can be provided with minimal energy consumption.

The purpose of the proposed solution is to simplify the design and increase the efficiency of anti-icing.

The goal is achieved due to the fact that:

1. Blowing with heated air after heating is carried out in the lower part of the reflector in the direction orthogonal to its rear surface.

2. The fan heater is installed in the lower part of the reflector with the direction of the air flow orthogonal to the back of the reflector.

3. A power voltage regulator connected to temperature sensors has been introduced into the switch unit of the control system.

The proposed technical solution is shown in figures 1, 2, in which the arrows show the direction of air movement respectively in the face and in profile. The de-icing system of a terrestrial parabolic antenna with a reflector 1 mounted on a frame made with blown stiffeners 2 includes a thermal cover 3 mounted on the frame with the formation of an air cavity 4 for blowing the reflector 1 and the frame, a fan heater 5 installed in the lower part of the reflector 1 with the direction air flow orthogonal to the back of the reflector 1, temperature sensors 6 and the switch unit 7 of the control system installed in the specified air cavity 4. In the switch Lock management system introduced power voltage regulator associated with temperature sensors.

Anti-icing system works as follows.

In order to prevent snow from sticking to the lower part of the reflector 1 at an ambient temperature close to 0 ° С, the fan heater 5 is switched on by the switching unit 7 of the control system for temperature sensors 6. An air vortex is formed with a pressure in the back of the lower part of the reflector 1 (with an air flow direction orthogonal to the back of the reflector 1), on the opposite side of which icing may occur. In the vortex zone, the highest intensity of the thermal and turbulent effects of the air flow on the part of the reflector is ensured with the possible formation of icing. Since the air in the vortex zone is the warmest and, therefore, has the lowest specific mass density, it will not only be distributed under the pressure created by the fan, but also due to natural convection to the upper part of the air cavity 4, as well as to the sides of the zone whirlwind. Radial blown stiffeners 2 of the frame not only allow air to circulate through them, but also ensure uniform distribution of the air flow over the entire surface of the reflector 1, improve the thermal connection of the air flow with the entire structure of the antenna due to its thermal conductivity and thereby improve temperature control.

As the air stream enters the upper part of the air cavity 4, it is cooled by the surface of the reflector 1, becomes with a higher specific density and, due to natural convection, is lowered into the vortex zone and this ensures a uniform, evenly distributed circulation of the air flow in the air cavity 4.

A power voltage regulator connected to temperature sensors 6 is introduced into the switching unit 7 of the control system, which regulates the thermal and flow-pressure power of the fan heater 5 according to the readings of the temperature sensors by changing their operating voltages. With an average value of the readings of temperature sensors 6 below minus 1 ° С, the switch unit of the control system 7 includes a fan heater 5 and its electric heater in operation at the maximum permissible supply voltages (in intensive operation mode), and with an average value of readings of temperature sensors 6 above plus 1 ° С, the switching unit of the control system 7 turns on the fan heater 5 and its electric heater in operation at the minimum supply voltages admissible for them (in the mode of reduced intensive work). This allows you to more efficiently use the energy consumption and resource of the fan heater to prevent icing of the antenna.

The essence of the proposed solution is that the back side of the lower part of the reflector, on the reverse side of which icing can form, is blown by the most intense vortex (turbulent) air flow with its highest temperature and thereby increase the efficiency of the method and device for its implementation. In addition, the efficiency of the method is further improved due to the natural circulation of air from the lower part of the air cavity to the upper one, the implementation of the method is simplified, since it basically requires only the installation of a fan heater. Keeping in the switch unit 7 of the control system of the voltage regulator of the fan heater power has allowed to further increase the efficiency of the proposed device.

The well-known sources of technical and patent information on this class of technology, the authors have not found distinctive features similar to the protected features.

The proposed technical solution is currently undergoing preparation for the introduction of enterprise development antennas.

Claims (3)

1. A method of anti-icing a terrestrial parabolic antenna, comprising blowing with heated air under a thermal cover of the back of the reflector with its frame, characterized in that blowing with heated air after heating is carried out in the lower part of the reflector in the direction orthogonal to its back surface. 2. The anti-icing system of a terrestrial parabolic antenna with a reflector mounted on a frame made with breathable stiffeners, including a thermal cover mounted on a frame with the formation of an air cavity for blowing the reflector and frame, a fan heater, temperature sensors and a commutator control unit installed in the air cavity characterized in that the fan heater is installed in the lower part of the reflector with an air flow direction orthogonal to the back side of the reflex the ector. 3. The de-icing system of a terrestrial parabolic antenna according to claim 2, characterized in that a power voltage regulator connected to temperature sensors is introduced into the switch unit of the control system.

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