Description

AIR CONDITIONING SYSTEM FOR COMMUNICATION EQUIPMENT AND CONTROLLING METHOD THEREOF

Technical Field

[1] The present invention relates to an air conditioning system for communication equipment and a method for controlling the same, and more particularly, to an air conditioning system for stably cooling the communication equipment although an indoor fan or an outdoor fan has a breakdown.

[2]

Background Art

[3] As is generally known in the art, an airconditioner employs evaporation heat which a refrigerant absorbs from surroundings when it evaporates. Typically, as refrigerant, liquids such as, ammonia, Freon, azeotropic refrigerant mixture, and chloromethyl which is easily evaporated at relatively low-temperatures.

[4] Typically, the air conditioner performs following processes: High-pressure vaporized refrigerant compressed by a compressor is changed into high-pressure refrigerant liquefied by heat exchange with outdoor air at a condenser; The high-pressure liquefied refrigerant is changed into low-pressure vaporized refrigerant by an expansion value and a capillary; and The low-pressure vaporized refrigerant flowed into an evaporator is evaporated by heat exchange with indoor air and the evaporated refrigerant is flowed back into the compressor. The refrigerant flowed into the compressor repeatedly circulates by the above processes. Air cooled by evaporation heat of the refrigerant occurred at the evaporator is blown into a predetermined space or objects to be cooled.

[5] As described above, a conventional air conditioner can cool objects by using characteristics of refrigerant to which a phase change, e.g.,condensation and evaporation easily occurs.

[6] In the meanwhile, there are many kinds of wire or wireless communication equipment in the base station for communication or communication vehicles. Typically, heat resulted from the operation of the communication equipment may cause mulfunction by breakdown of components in communication equipment or a contact error between two nodes in communication equipment. For this reason, it is necessary to cool the communication equipment all year round to minimize malfuction if the communication equipment due to heat generation therein.

[7] There is a problem that the conventional air conditioner for communication equipment does not appropriately use outdoor air or indoor air to cool the communication equipment according to surrounding temperature of the communication

equipment. Also, there is another problem that since the conventional air conditioner is continueously operated by external power source, the power consumption of the conventional air conditioner is very high and the cooling efficiency of itself is very low.

[8] In order to solve the problem described above, Applicant invented an air conditioning system for communication equipment and a method for controlling the air conditioning system being able to reduce power consumption by operating selectively a outdoor unit and filed an application (Korea application number 10-2005-0014790) regarding the same.

[9] However, the application has a problem that communication equipment to be cooled can not be cooled if an indoor fan or an outdoor fan has a breakdown.

[10]

Disclosure of Invention Technical Problem

[11] The present invention is directed to provide an air conditioning system for communication equipment and a method for control the air conditioning system to for stably cooling the communication equipment although an indoor fan or an outdoor fan has a breakdown.

[12]

Technical Solution

[13] In accordance with an aspect of the present invention, there is provided an air conditioning system for communication equipment including a first cooling unit, a second cooling unit and a third cooling unit.

[14] The first cooling unit includes an outdoor heat exchanger for exchanging heat with outdoor air, an indoor heat exchanger for exchanging heat with indoor air, a pair of indoor fans arranged in one side of the indoor heat exchanger, a pair of outdoor fans arranged in the one side of the outdoor heat exchanger, a circulating pipe for circulating a first refrigerant, a circulate pump arranged on a predetermined position of the circulating pipe, a refrigerant temperature sensor arranged on an outdoor predetermined position of the circulating pipe, a bypass pipe for circulating the first refrigerant to avoid passing through the outdoor heat exchanger, a first and a second bypass valves arranged on the circulating pipe and the bypass pipe, respectively, a first heat exchange tube arranged on the circulating pipe, a first brine heat exchanger having the first heat exchange tube therein, an indoor temperature sensor for measuring indoor temperature of a base station, and an outdoor temperature sensor for measuring outdoor temperature of the base station.

[15] The second cooling unit includes a first compressor for changing a second refrigerant into a high-temperature and high-pressure second refrigerant, a first condenser for

exchanging heat between outdoor air and the high-temperature and high-pressure second refrigerant, a first expansion valve for changing the second refrigerant provided from the first condenser into a low-temperature and low-pressure second refrigerant, a first evaporator for exchanging heat with the first heat exchange tube wherein the first evaporator is arranged in the first brine heat exchanger arranged between the first expansion valve and the first compressor.

[16] The third cooling unit includes a second compressor for changing a third refrigerant into a high-temperature and high-pressure third refrigerant, a second condenser for exchanging heat between outdoor air and the high-temperature and high-pressure third refrigerant, a second expansion valve for changing the third refrigerant provided from the condenser into a low-temperature and low-pressure third refrigerant; and a second evaporator arranged between the second expansion valve and the second compressor wherein the first cooling unit includes a second heat exchange tube arranged at an outlet of the first second heat exchange tube and a second brine heat exchanger having the second heat exchange tube and the second evaporator therein.

[17] In accordance with another aspect of the present invention, there is provided a method for controlling the air conditioning system including a first step of checking whether the indoor fans and the outdoor fans are out of order or not; a second step of announcing a display alarm if one of the pair of indoor fans is out of order; a third step of stopping the operation of the indoor fan being out of order if at least one of the indoor fans is out of order; a fourth step of stopping the operation of the first to the third cooling units if both of the pair of indoor fans are out of order, a fifth step of announcing a display alarm if one of the pair of outdoor fans is out of order, a sixth step of stopping the operation of the indoor fan being out of order if at least one of the outdoor fans is out of order; and a seventh step of stopping the operation of the first to the third cooling units if both of the pair of outdoor fans are out of order.

[18]

Advantageous Effects

[19] The air conditioning system for communication equipment according to the present invention includes a pair of indoor fans and a pair of outdoor fans. Therefore, although one of the pair of indoor fans or the pair of outdoor fans is out of order, the air conditioning system can stably cool the communication equipment.

[20]

Brief Description of the Drawings

[21] Fig. 1 is a block diagram showing an air conditioning system for communication equipment in accordance with an embodiment of the present invention.

[22] Fig. 2 is a block diagram showing a cooling operation using a first cooling unit in an

air conditioning system for communication equipment in accordance with an embodiment of the present invention.

[23] Fig. 3 is a block diagram showing a cooling operation using a first cooling unit and a second cooling unit in an air conditioning system for communication equipment in accordance with an embodiment of the present invention.

[24] Fig. 4 is a block diagram showing a cooling operation using a first cooling unit to a third cooling unit in an air conditioning system for communication equipment in accordance with an embodiment of the present invention.

[25] Fig. 5 is a flow chart illustrating a method for controlling an air conditioning system for communication equipment in accordance with an embodiment of the present invention.

[26]

Best Mode for Carrying Out the Invention

[27] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to drawings provided according to the embodiment of the present invention.

[28] Fig. 1 is a block diagram showing an air conditioning system for communication equipment in accordance with an embodiment of the present invention.

[29] As shown, the air conditioning system for communication equipment in accordance with an embodiment of the present invention includes a first cooling unit 100 for directly cooling the communication equipment (not shown), and a second and a third cooling units 200 and 300 for indirectly cooling the communication equipment by cooling a first refrigerant of the first cooling unit 100. The first, second, and third cooling units 100, 200, and 300 are arranged in an indoor unit 500 and an outdoor unit 600. The indoor unit 500 is arranged with the communication equipment in a base station. The outdoor unit 600 is arranged outside the base station. The indoor unit 500 includes a temperature sensor 510 for measuring indoor temperature and the outdoor unit 600 includes a temperature sensor 610 for measuring outdoor temperature.

[30] The first cooling unit 100 is first described hereinafter. An indoor heat exchanger 110 arranged in the indoor unit 500 is a component for heat exchange between indoor air and the first refrigerant. Indoor fans 116 are arranged at one side of the indoor heat exchanger 110 for transferring air cooled by heat exchange of the indoor heat exchanger 110. Outdoor heat exchangers 120 are arranged at the outdoor unit for heat exchange between outdoor air and the first refrigerant. The outdoor heat exchangers 120 are arranged in series or in parallel with reference to a position of outdoor fans 122. The indoor heat exchanger 110 and the outdoor heat exchangers 120 are connected by a circulating pipe 130 filled with the first refrigerant. Although one of the

indoor fans 116 or one of the outdoor fans 122 becomes out of order since the indoor fans 116 include a pair of fans and the outdoor fans 122 include a pair of fans, the air conditioning system can stably cool the communication equipment using the other fan not being out of order.

[31] As described above, the circulating pipe 130 is filled with the first refrigerant and the first refrigerant circulates through the circulating pipe 130. A circulation pump 132 compulsively circulates the first refrigerant through the circulating pipe 130. A pressure switch 134 measures pressure of the first refrigerant at the inlet of the indoor heat exchanger 110. A flowing switch 136 measures the flow amount of the first refrigerant at the outlet of the indoor heat exchanger 110.

[32] A heat coil 180 and a refrigerant temperature sensor 190 are arranged on the portion of the circulating pipe 130 installed in the out door unit 600, and the heat coil 180 prevents the circulation pipe 130 from being broken by cold weather. Also, a first heat exchange tube 162 and a second heat exchanged tube 164 are arranged in series on the circulating pipe 130 wherein the first heat exchange tube 162 is for exchanging heat with a first evaporator 240 of the second cooling unit 200 and the second heat exchange tube 164 is for exchanging heat with a second evaporator 340 of the third cooling unit 300. The first brine heat exchanger 172 has the first heat exchange tube 162 therein and the second brine heat exchanger 174 has the second heat exchange tube 164 therein.

[33] A bypass pipe 140 is arranged for circulating the first refrigerant so that the first refrigerant avoid passing through the outdoor heat exchangers 120. A first bypass valve 152 is provided on the circulation pipe 130 and a second bypass valve 154 is provided on the bypass pipe 140. The first bypass valve 152 and the second bypass valve 154 can be opened at the same time or a selected one of the two valves 152 and 154 can be opened.

[34] The circulation pump 132 includes a pair of pumping units which are connected in parallel. If one of the pumping units is out of order, since the other can be normally operated, circulation of the refrigerant can be carried out. Thus, cooling operation of the first cooling unit 100 can be regularly performed. Herein, as described above, the heat coil 180 is for preventing components of the air conditioning system from being damaged with cold.

[35] The second cooling unit 200 includes a first compressor 210 for changing a second refrigerant into a high-temperature and high-pressure second refrigerant, a first condenser 220 for exchanging heat between outdoor air and the high-temperature and high-pressure second refrigerant, a first expansion valve 230 for changing the second refrigerant provided from the first condenser 220 into a low-temperature and low- pressure second refrigerant, the first evaporator 240 arranged in the first brine heat

exchanger 172 exchanges heat with the first heat exchange tube 162. Herein, the first evaporator 240 is arranged between the first expansion valve 230 and the first compressor 210.

[36] The third cooling unit 300 includes a second compressor 310 for changing a third refrigerant into a high-temperature and high-pressure third refrigerant, a second condenser 320 for exchanging heat between outdoor air and the high-temperature and high-pressure third refrigerant, a second expansion valve 330 for changing the third refrigerant provided from the condenser into a low-temperature and low-pressure third refrigerant, and the second evaporator 340 arranged between the second expansion valve 330 and the second compressor 310. Herein, the second evaporator 340 is for exchanging heat with a second heat exchange tube 164 and is arranged in a second brine heat exchanger 174.

[37] The first refrigerant used in the first cooling unit 100 according to the present invention includes water. The second refrigerant used in the second cooling unit 200 and the third refrigerant used in the third cooling unit 300 includes one selected from the group consisting of ammonia, azeotropic refrigerant and chloride methyl, or combinations thereof.

[38] A cooling operation of the air conditioning system according to the present invention is described hereinafter. The cooling operation is controlled according to indoor temperature and the outdoor heat exchangers 120 is controlled according to outdoor temperature and the temperature of the first refrigerant. Herein, the first refrigerant includes brine.

[39] First, the indoor temperature of the base station is measured. If the measured indoor temperature is higher than a first reference temperature, e.g., 25 degrees, the first cooling unit 100 is operated (Referring to Fig. X). This case is called a first cooling operation. In this case, if outdoor temperature is lower than that of the first refrigerant, the first bypass valve 152 is opened and the outdoor heat exchangers 120 is operated. Herein, the second bypass valve 154 is closed. If outdoor temperature is higher than that of the first refrigerant, the second bypass valve 154 is opened and the operation of the outdoor heat exchangers 120 is stopped. Herein the first bypass valve 152 is closed.

[40] If the measured indoor temperature is higher than a second reference temperature, e.g., 26.5 degrees, the first cooling operation is not sufficient to cool the indoor space of the base station. In this case, both of the first cooling unit 100 and the second cooling unit 200 are operated. This case is called a second cooling operation (Referring to Fig. 3). While the first cooling unit 100 and the second cooling unit 200 are operated, heat exchange between the first refrigerant and the second refrigerant is performed in the first brine heat exchanger 172. The first refrigerant cooled by the above heat exchange is used to cool communication equipment in the base station.

[41] Also, if the measured indoor temperature is higher than a third reference temperature, e.g., 27.5 degrees, the second cooling operation is not sufficient to cool the indoor space of the base station. In this case, all of the first, second, and third cooling units 100, 200, and 300 are operated. This case is called a third cooling operation. During the third cooling operation, heat exchange between the first refrigerant and the second refrigerant is first performed in the first brine heat exchanger 172 and heat exchange between the first refrigerant and the third refrigerant is secondly performed in the second brine heat exchanger 174. The first refrigerant cooled by the above heat exchanges is used to cool communication equipment in the base station.

[42] As described above, if outdoor temperature is lower than that of the first refrigerant during the second cooling operation and the third cooling operation, the first bypass valve 152 is opened and the outdoor heat exchangers 120 is operated. If outdoor temperature is higher than that of the first refrigerant during the second cooling operation and the third cooling operation, the second bypass valve 154 is opened and the operation of the outdoor heat exchangers 120 is stopped.

[43] Referring to Figs 1 to 5, hereinafter, it is described a method for control air conditioning system for communication equipment and a controlling method thereof according to present invention.

[44] As shown in Fig. 5, it is checked whether the indoor fans are out of order or not

(S 102). As descried above, in this embodiment, it is first checked whether the indoor fans are out of order. In another embodiment, it can be first checked whether the outdoor fans are out of order. A display alarm is announced if the pair of indoor fans 116 is out of order (S 104). Herein, the display alarm is announced even though at least one of the pair of indoor fans is out of order.

[45] If one of the pair of indoor fans is out of order (S 106), the indoor fan being out of order is stopped and the other indoor fan is operated to perform the operation of heat exchange in the indoor heat exchanger 110 (S 108). If both of the pair of indoor fans 116 are out of order, the operation of the first, second, and the third cooling units 100, 200, and 300 are stopped (Sl 12). Also, while one of the pair of indoor fans 116 is operated, the operation of the first to the third cooling units 100, 200, and 300 is stopped (S 112) if the other is out of order (S 110).

[46] On condition that both of the pair of indoor fans 116 are out of order are not out of order, it is checked whether the pair of outdoor fans 122 is out of order or not (S 114). A display alarm is announced if the pair of outdoor fans 122 is out of order (Sl 16). If one of the pair of outdoor fans 122 is out of order (Sl 18), the outdoor fan being out of order is stopped and the other outdoor fan is operated to perform the operation of heat exchange in the outdoor heat exchangers 120 (S 120). If both of the pair of indoor fans 116 are out of order the operation of the first to the third cooling units 100, 200, and

300 is stopped (S 124). Also, if the other is out of order (S 122) while one of the pair of outdoor fans 122 is operated, the operation of the first, second, and the third cooling units 100, 200, and 300 is stopped (S 124).

[47] As described above, the air conditioning system includes a pair of indoor fans 116 and a pair of outdoor fans 122. Therefore, although the one of indoor fans 116 or one of outdoor fans 122 becomes out of order and then stops to operate, the air conditioning system can stably cool the communication equipment with using the other indoor fan or the other outdoor fan.

[48] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the air that various changes and modifications may be made without departing from scope of the invention as defined in the following claims.