Abstract: Disclosed herein are a spectrum sensing apparatus and method for a cognitive radio (CCR) network in a non-Gaussian noise environment and an FC apparatus and CCR system using the same. The cooperative cognitive radio (CCR) system includes M cognitive radios (CRs), and a fusion center (FC). Each of the M CRs samples a baseband signal obtained by down-converting a radio signal detected in the corresponding frequency spectrum, and generates spectrum sensing information (SSI) indicating that a PU signal has been detected based on the results of the sampling. The FC determines a joint threshold ?FC that can maximize an expected average throughput of a secondary user (SU) signal in a given communication environment including a maximum interference condition, calculates a joint test statistic from received M pieces of SSI, and determines whether the PU signal is present by comparing the calculated joint test statistic with the joint threshold.

Abstract: The present invention relates to a cartridge-type inline heater including: a heat exchanging unit including a body part in which a mounting part is formed in a longitudinal direction, and swirl parts coiled in a spiral along the longitudinal direction of the body part, and configured to induce a flowing-in working fluid to flow along the swirl parts; and a heater inserted in a longitudinal direction of the heat exchanging part to heat the working fluid which is in contact with the heat exchanging unit. Accordingly, the cartridge-type inline heater capable of heating the working fluid so as to have improved durability and uniform temperature distribution is provided.

Abstract: A method for controlling a multi-unit air conditioning system adapted to cool or heat room spaces while passing a refrigerant in one direction or in a reverse direction is disclosed. In the method, which is applied to a multi-unit air conditioning system including at least three compressors, when a compressor re-operation is repeatedly carried out after all of the compressors have been turned off, to turn on again at least one of the compressors, repetition of the compressor re-operation is carried out for a predetermined number of different orders in such a manner that at least one of the compressors is turned on first in an associated order of the repeated compressor re-operation.

Abstract: A supercooling apparatus of a simultaneous cooling and heating type multiple air conditioner comprises a liquid pipe header connected to outdoor heat exchangers, a plurality of branch liquid pipes branched from the liquid pipe header and connected to a plurality of indoor heat exchangers, respectively, and a supercooling mechanism mounted at least one of the branch liquid pipes for cooling refrigerant flowing to the indoor heat exchangers. The liquid refrigerant discharged from the heating-side indoor heat exchangers is supercooled by supercooling heat exchangers, and is then introduced into the cooling-side indoor heat exchangers. Consequently, noise generated from the cooling-side heat exchangers during the simultaneous cooling and heating operation is reduced, and cooling capacity of the multi air conditioner is improved.

Abstract: A multi type air-conditioner is provided. The multi type air conditioner includes an outdoor unit having a plurality of outdoor heat exchangers that heat-exchanges with outdoor air and a compressor that compresses a refrigerant; a plurality of indoor units that performs either cooling or heating; a high pressure pipe connected between a discharge side of the compressor and the plurality of indoor units; a low pressure pipe connected between a suction side of the compressor and the plurality of indoor units; and a refrigerant exhauster provided between the high pressure pipe and the low pressure pipe. The refrigerant exhauster discharges a liquid refrigerant to the low pressure pipe when the liquid refrigerant is accumulated in the high pressure pipe, whereby degradation of cooling capability due to a lack of refrigerant may be prevented by minimizing accumulation of the liquid refrigerant in the high pressure pipe in a cooling operation mode.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: Provided is an air conditioner, particularly, an apparatus and method for controlling a super-heating degree in a heat pump system for preventing a liquid refrigerant from flowing into a compressor. The method includes: operating the heat pump system; receiving a present outdoor temperature, a pipe absorption temperature and a low pressure value of a compressor, respectively; computing a present absorption super-heating degree from a difference between the absorption temperature of the compressor and a saturated temperature at a low pressure side; and comparing an targeted absorption super-heating degree set in advance, with the computed present absorption super-heating degree according to the received outdoor temperature, and controlling the system so that the present absorption super-heating degree may follow the targeted absorption super-heating degree.

Abstract: A multi type air conditioner comprises: an outdoor unit including an outdoor heat exchanger heat-exchanged with the outdoor air, a compressor compressing a refrigerant, and a first four-way valve and a second four-way valve switching a refrigerant flow path; indoor units performing at least one of cooling operation and heating operation; and a distributor including a low pressure pipe connected between the first four-way valve and each of the indoor units, a high pressure pipe connected between the second four-way valve and each of the indoor units, and a refrigerant pipe connected between the outer heat-exchanger and each of the indoor units. Accordingly, flow resistance of a refrigerant is reduced in heating operation, thereby improving heating performance and heating efficiency, and the amount of refrigerant accumulated within a high pressure pipe is minimized in cooling operation, thereby improving cooling performance and cooling efficiency.

Abstract: Disclosed is an apparatus and method for preventing liquid refrigerant accumulation in an accumulator of an outdoor unit of an air conditioner. The method includes the steps of: determining a state of a compressor; if the compressor is in standby mode or off state, turning on a four-way valve; determining whether the state of the compressor in standby mode or off state continues longer than a predetermined amount of time; and if the state of the compressor continues longer than the predetermined amount of time, closing an expansion valve. Particularly, high-pressure refrigerant flows in the closed expansion valve while low-pressure refrigerant flows in a check valve through the four-way valve.

Abstract: Disclosed is a method for controlling an air conditioner. In particular, driving modes of elements, namely sucking/discharge compressure, of the compressor in operation are determined so that variable means are controlled to ensure for the elements of the compressor to be within predetermined value ranges in safe area. According to the present invention, vibrations/noises that usually occur when the compressor is in unstable area are greatly reduced and thus, the compressor can be protected from damages.

Abstract: A system for controlling an air conditioner includes a plurality of outdoor units each having at least one compressor and an outdoor heat exchanger, an indoor unit connected to the outdoor units by a refrigerant tube, the indoor unit having an indoor heat exchanger, and a pressure regulating tube for equalizing pressure according to an operation mode. The pressure regulating tube is connected between the outdoor units.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: A refrigerant bypassing and filtering apparatus of an air conditioner is disclosed which is capable of effectively removing foreign matter such as slag produced in a refrigerant line, not only when the air conditioner is initially operated, but also during normal operation of the air conditioner. The apparatus includes at least one bypass line adapted to guide a refrigerant to bypass a main line through which the refrigerant flows between an outdoor unit and an indoor unit, a strainer arranged at the bypass line, a first valve arranged at the main line between opposite ends of the bypass line connected to the main line, and second valves arranged at the bypass line.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: Air conditioner, and method for controlling an operation of the same, the air conditioner including a sheath heater in the accumulator for heating the refrigerant in room heating for delaying deposition of frost on the outdoor heat exchanger. The sheath heater includes a coil formed heat generating part, and two electrodes connected to the heat generating part for supplying power. The method including the step of varying the heat generating rate of the sheath heater with an exterior temperature or a capacity of the indoor unit, thereby delaying deposition of frost on the outdoor heat exchanger.

Abstract: Multi-type air conditioner including an outdoor unit installed in an outdoor, including a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, and an outdoor heat exchanger connected to the refrigerant flow controlling part, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, a plurality of, at least two, distributors between the outdoor unit and the plurality of indoor units for improving installation freedom of the plurality of indoor units, selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again, and a device for shutting off introduction of the refrigerant into the distributors connected to inoperative indoor uni

Abstract: A multi type air conditioner comprises: an outdoor unit including an outdoor heat exchanger heat-exchanged with the outdoor air, a compressor compressing a refrigerant, and a first four-way valve and a second four-way valve switching a refrigerant flow path; indoor units performing at least one of cooling operation and heating operation; and a distributor including a low pressure pipe connected between the first four-way valve and each of the indoor units, a high pressure pipe connected between the second four-way valve and each of the indoor units, and a refrigerant pipe connected between the outer heat-exchanger and each of the indoor units. Accordingly, flow resistance of a refrigerant is reduced in heating operation, thereby improving heating performance and heating efficiency, and the amount of refrigerant accumulated within a high pressure pipe is minimized in cooling operation, thereby improving cooling performance and cooling efficiency.

Abstract: A multi type air-conditioner comprises: an outdoor unit having outdoor heat exchangers heat-exchanged with outdoor air and a compressor for compressing a refrigerant; indoor units for performing either cooling or heating; a high pressure pipe connected between a discharge side of the compressor and the indoor units; a low pressure pipe connected between a suction side of the compressor and the indoor units; and a refrigerant exhauster provided between the high pressure pipe and the low pressure pipe, for discharging a liquid refrigerant to the low pressure pipe when the liquid refrigerant is accumulated in the high pressure pipe, whereby degradation of cooling capability due to a lack of refrigerant can be prevented by minimizing accumulation of the liquid refrigerant in the high pressure pipe in a cooling operation mode.

Abstract: Disclosed is an outdoor-unit software upgrade system and method. The outdoor-unit software upgrade system includes: a software upgrade application which is an application program installed in a computer terminal and transmits outdoor-unit upgrade software, which is stored in a storage unit and selected by a user, to a data output port; a first wireless communication unit which is coupled with the data output port, packtizes and wirelessly transmits the outdoor-unit upgrade software data outputted from the data output port; and a second wireless communication unit which receives packet data from the first wireless communication unit set to be connected to the second wireless communication unit, converts the packet data into the outdoor-unit upgrade software data, and transmits the outdoor-unit upgrade software data to a controller mounted on a main board of an outdoor unit.

Abstract: Method for operating a multi-type air conditioner including the steps of calculating a total heating load of the indoor units that are to carry out heating, and a total cooling load of the indoor units that are to carry out cooling, and determining an operation pattern of the outdoor unit according to the total cooling load and the total heating load. The method further including the steps of recalculating the total heating load and the total cooling load of the indoor units according to change of operation temperature of the indoor units, and changing the operation pattern of the outdoor units according to the recalculated total heating load and the total cooling load.