Patent ID: 7823397

Claim:
A system for detecting a clogged state of a pipe of a heat pump type multi-air conditioner which comprises a plurality of outdoor units and a plurality of indoor units, comprising: a plurality of first pressure detection sensors for detecting a pressure of a refrigerant sucked into each outdoor unit; a plurality of second pressure detection sensors for detecting a pressure of a refrigerant discharged from each outdoor unit; a plurality of pipe temperature detection units for detecting a temperature of each pipe of a plurality of indoor heat exchangers; a storage unit for storing first pressure data corresponding to each temperature of each pipe of each indoor heat exchanger detected by the plurality of pipe temperature detection units when performing an air-conditioning operation and second pressure data corresponding to each temperature of each pipe of each indoor heat exchanger detected by the plurality of pipe temperature detection units when performing a heating operation; and a microcomputer for comparing low pressure data detected by an arbitrary first pressure detection sensor among the plurality of first pressure detection sensors with the first pressure data and recognizing that a pipe of an outdoor unit having the arbitrary first pressure detection sensor is clogged if a difference value between the low pressure data and the first pressure data is greater than a first pre-set value, while the pipe is recognized to be in a normal state when the difference value is not greater than the first pre-set value when performing the air-conditioning operation, and comparing high pressure data detected by an arbitrary second pressure detection sensor among the plurality of second pressure detection sensors with the second pressure data and recognizing that a pipe of an outdoor unit having the arbitrary second pressure detection sensor is clogged if a difference value between the high pressure data and the second pressure data is greater than a second pre-set value, while the pipe is recognized to be in the normal state when the difference value is not greater than the first pre-set value when performing the heating operation.