KR20020052788A - Apparatus for heatproof of outdoor BTS - Google Patents

Abstract

PURPOSE: A heat protection system in an outdoor type BTS(Base station Transceiver Subsystem) is provided to implement a heat protection effect in a high temperature environment and an adiabatic effect for the protection of components in a low temperature environment without using any external power. CONSTITUTION: An apparatus for testing low temperature operation characteristics for heat pipes is composed of a power supply(100), a plurality of heat pipes(210), a chamber(200), a data logger(300), and a PC(400). The power supply(100) supplies power for the operation of a heat protection system. The heat pipes(210) exchange heat using a working fluid(220). The chamber(200), in which the working fluid(220) is installed, provides an environment for tests. The data logger(300) has a function to automatically record all physical processors about the lapse of time. The PC(400) measures an operation characteristic dependent on ambient temperature.

Description

Apparatus for heatproof of outdoor BTS

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe low temperature characteristic application system in a wireless communication base station using working fluid icing. In particular, the heat pipe is a known working temperature range (Table 1). The present invention relates to a heat dissipation device of an outdoor type base station that can be applied to escape from the heat pipe and prevents heat pipe heat dissipation in a low temperature environment, thereby protecting an electronic equipment system exposed to a low temperature environment.

In general, a heat pipe is a device having the best heat transfer performance. As shown in FIG. 1, a working fluid circulated in a closed space therein is continuously transferred from liquid to steam. By transferring heat using the latent heat accompanying the change (liquid-> gas-> liquid), the performance is remarkable compared to the ordinary heat transfer device using a single-phase working fluid. These heat pipes use a so-called capillary structure called a wick or groove to return liquid working fluid from the condenser to the evaporator. Silver causes a capillary phenomenon caused by the surface tension of the liquid, and the capillary pressure generated by the capillary phenomenon returns the working fluid from the condenser to the evaporator.

2 is a view showing a wireless communication system according to the prior art, as shown, a reverse link showing an electromagnetic wave communication link transmitted from a mobile station 10, a base station 20, and a mobile station 10 to a base station 20. 30 shows a wireless communication system including a forward link 40 representing an electromagnetic wave communication link transmitted from the base station 20 to the mobile station 10.

In the above wireless communication system based on the cellular principle, the service area is divided into a plurality of small areas 50, 52, 54, 56 called cells as shown in FIG. Each cell has cell sites 58, 60, 62, and 64 that are equipped with a wireless device called a base station transceiver subsystem (BTS). For internal use of multiple cell layouts, for certain areas (campus, playgrounds, airports, shopping malls), for supplementing macro cells or mini cells, or for special events to have a gradual coverage such as macro cell, micro cell, pico cell, etc. within a specific area. It can be used as a temporary or remote location for a local or natural disaster area.

4 is a block diagram illustrating a block of a base station connected to a terrestrial PSTN according to the related art.

As shown therein, the base station 66 'provides a link to the subscriber or mobile station 10. As shown in FIG. Each base station 66, 66 ′ is connected to a base station controller (BSC) 70 and includes one or more antennas 67, 67 ′. In addition, multiple base stations may be connected to the control station. Each control station 70, 70 'is connected to a Mobile Switching Center (MSC) 72, which is connected to a Public Switched Telephone Network (PSTN).

5 is a diagram illustrating a functional block configuration of a base station according to the related art.

As shown, the existing base station 66 includes five main functional blocks. The five main functional blocks are a battery backup unit including an RF front end 81, multiple transceivers 82, multiple modem processors 83, controllers 84, and multiple batteries. It consists of 86. The controller 84 is connected to the control station 70 via a T1 or E1 line 85, and the RF front end 81 is generally connected to an antenna 67 installed at the top of a tower or pole. Connected.

In a typical system, the five main functional blocks shown in FIG. 5 are contained in one or more housings. The housing is typically a welded enclosure to package the electronics therein and also to protect it from harmful external environmental influences or unauthorized access. Unlike placing electronics in the main chamber 80, the battery of the battery backup unit 86 is typically stored in a battery chamber that is separated from the main chamber 80 and sealed to meet industry standards. .

Since the base station 66 is installed not only indoors but also outdoors where the temperature varies from -40 ° C to + 50 ° C, the internal temperature of the enclosure is controlled from + 5 ° C to + 65 ° C during the operation of the base station 66. To do this, a heating / cooling thermostat system is required. Conventional base station heating / cooling temperature control systems have used a one-step heating / cooling process using a compressor cooling system or a conventional plate heat exchanger. Such a system has a problem of high failure rate and high maintenance cost, and also the system is unnecessarily heavy and large enough to make transportation, installation and removal very difficult, especially when using a compressor cooling system. In addition, the batteries of the battery backup unit 86 are stored in a chamber separate from the main chamber 80 so that the batteries are not subjected to heating and cooling.

Thus, there is a need for a base station heating / cooling system that enables heating and cooling temperature control of the battery chamber as well as the main chamber without the need for a compressor cooling system.

In addition, the passive cooling method using an external power source has the same difference between ambient temperature in the high temperature and low temperature environment. And the heat dissipation system in the communication base station is designed based on the high temperature environment, so the temperature inside the low temperature environment (domestic standard: -30 ℃) is out of the operating temperature range of the components, and the life of the components is shortened. , Failure of the base station function or the like. Therefore, additional heating devices are required for the protection of the components, and additional devices such as an increase in the capacity of the power supply and an increase in the back-up battery capacity due to the installation of a heater. You will need

Accordingly, the present invention is proposed to solve the above problems of the prior art,

An object of the present invention is to use a base station heat dissipation system having a heat dissipation effect in a high temperature environment and a thermal insulation effect for the protection of components in a low temperature environment by applying different conductance with the outside air in a high / low temperature environment without using any external power To provide a heat dissipation device in an outdoor base station to implement.

The heat dissipation device of the outdoor base station according to the present invention for achieving the above object,

By applying a heat pipe with water as a working fluid to the heat dissipation system of a wireless communication base station exposed to outdoor environmental conditions (-30 ° C.), the heat pipe is stopped by using the characteristic of water freezing in a low temperature environment. Therefore, the heat conduction conduction between the system and the outside air is increased, and the inside of the system can maintain the image by the heat of the component.

1 is a cross-sectional view schematically showing the internal structure of a typical heat pipe,

2 is a view showing a wireless communication system according to the prior art;

3 is a diagram illustrating a cellular communication grid and a cell site according to the prior art;

4 is a block diagram showing a block configuration of a base station connected to a terrestrial PSTN according to the prior art;

5 is a block diagram showing a functional block configuration of a base station according to the prior art;

Figure 6 is a block diagram showing the configuration of the heat pipe low temperature operation characteristics experimental apparatus according to the present invention,

7 is a view showing the experimental result data according to FIG.

8 is a graph showing the temperature change of the heat pipe evaporator and the condenser according to the outside temperature in the present invention;

9 is a graph showing the temperature difference between the outdoor air for each working fluid in the present invention, Figure 9a is a graph showing the temperature difference between the outdoor air according to the water, Figure 9b is a graph showing the temperature difference according to the methanol.

<Explanation of symbols for the main parts of the drawings>

100; Power Supply

200; Chamber

210; Heat Pipe

220; Working Fluid

300; Data Lagger

400; Notebook Personal Computer

Hereinafter, a preferred embodiment of a heat dissipation system in a wireless communication base station of the present invention according to the technical spirit as described above in detail with reference to the accompanying drawings.

First, the internal working fluid maintains a liquid state for endotherm, and the application temperature range for each working fluid is as shown in Table 1 below.

Table 1 shows the application temperature ranges of the working fluids mainly used commercially.

Working fluid Melting Point [℃] Boiling Point [℃] Useful Range [℃] ethanol -112 78 0 to 130 Methanol -98 64 10 to 130 ammonia -78 -33 -60 to 100 water 0 100 30 to 200

In general, the normal operation of the heat pipe becomes impossible when the use of the heat pipe in Table 1 is outside the operating temperature range. Each system therefore chooses a working fluid that is appropriate for the environment in which it is located.

Figure 6 is a block diagram showing the configuration of the heat pipe low temperature operation characteristic experimental apparatus according to the present invention.

One or more heat pipes 210 for exchanging heat using a working fluid 220 when power is supplied from the power supply 100 and a power supply 100 for supplying power for operating a heat radiating device. ), A chamber 200 for mounting the working fluid 220 therein and providing an environment for experiments, and a data automatic register having a function of automatically recording all physical processors regarding the passage of time ( Data Logger) 300, and a notebook PC (Notebook Personal Computer) 400 for measuring the operating characteristics according to the ambient temperature (Ambient Temperature).

As shown in the drawing, when power is applied from the power supply device 100 to the heat pipe 210 in the chamber 200, the heat pipe 210 continuously uses water as the working fluid 220. Heat is transferred by using latent heat accompanying when causing a phase change from liquid to steam, and when the heat pipe 210 is operated, the data automatic register 300 measures the transferred heat to change temperature over time. Automatically record all operating characteristics for. The notebook PC 400 outputs an operation characteristic according to the ambient temperature recorded by the data automatic register 300 and outputs a data value.

The data measured during the experiment are shown in FIG. 7, and FIGS. 8 and 9 illustrate the results generated based on the experiment.

FIG. 7 shows data values measured based on the experiment according to FIG. 6.

FIG. 8 is a graph illustrating changes in the heat pipe evaporator and the condensation unit temperature according to the outside air temperature in FIG. 6, and illustrates the actual temperature of the heat pipe evaporator which means the inside of the wireless communication base station.

As shown, in the case of the evaporator, all of the tested data maintains the temperature of the heat pipe according to the outside temperature above 0 ° C, and the condenser is proportionally heat pipe temperature according to the change of the external temperature. Rises.

9 is a graph showing the temperature difference between the outdoor air for each working fluid in the present invention, Figure 9a is a graph showing the temperature difference between the outdoor air according to the water, Figure 9b is a graph showing the temperature difference according to the methanol.

As shown in the figure, it can be seen that the temperature difference between the outdoor air and the temperature difference between the methanol and the outdoor air in the case of water in a low temperature environment (-20 ° C). That is, in the case of water, unlike the methanol at -20 ℃ shows a sharp increase in the temperature difference between the outside air, which can be seen that the heat insulation effect occurs.

That is, the working fluid (water) in the heat pipe 210 freezes in a low temperature environment (about -20 ° C), thereby stopping the heat radiation operation. At this time, heat is generated inside the system (base station), and heat generated by discontinuing operation of the heat dissipation device is not released, thereby naturally obtaining a thermal insulation effect.

According to the above-described "heat dissipation system in a wireless communication base station", by applying the heat pipe outside the existing known operating temperature range, it is impossible to dissipate the heat pipe in a low temperature environment, electrons exposed to low temperature environment It has the advantage of protecting the equipment system.

In addition, by using a heat pipe to prevent deterioration of the equipment in the environmental conditions of the outdoor communication base station, it is possible to improve the stability of the equipment through the freezing of the working fluid.

In addition, the communication base station of the passive cooling system (Passive Cooling System) that does not use external power has the advantage that the heat conduction conduction with the outside air can be variably applied in a high / low temperature environment.

Claims (1)

In the heat radiation device of the outdoor base station, A heat pipe that uses water as a working fluid to discharge heat generated inside the base station to the outside in a high temperature environment, and to prevent the heat generated inside the base station to be discharged to the outside by freezing the working fluid in a low temperature environment; The heat dissipation device of the outdoor type base station, characterized in that it comprises a power supply for supplying driving power to the heat dissipation device.