Air conditioner in electric vehicle

Abstract

The present invention relates to an air conditioner in an electric vehicle, and more particularly to an air conditioner in an electric vehicle, which can make continuous heating operation even in defrosting operation, can enhance heating efficiency and performance even in the defrosting operation, and can recover heat discharged from various components of the electric vehicle even in the defrosting operation for preventing liquid refrigerant from being introduced to a compressor.

1 . An air conditioner in an electric vehicle having a battery and a driving unit comprising:
 a compressor for compressing refrigerant;   an indoor heat exchanger for introducing the refrigerant thereto from the compressor in heating operation;   first and second outdoor heat exchangers connected to the indoor heat exchanger;   first and second refrigerant flow passage controllers provided between the indoor heat exchanger and each of the outdoor heat exchangers; and   a controller for making defrosting operation of the first outdoor heat exchanger if the first outdoor heat exchanger meets at least one of defrosting operation starting conditions of an outdoor temperature, and refrigerant temperatures at an inlet and an outlet of the outdoor heat exchanger in the heating operation, and controlling the first and second refrigerant flow passage controllers for making the refrigerant passed through the indoor heat exchanger to be introduced only to the second outdoor heat exchanger according to a state of remained charge of the battery or the outdoor temperature.   
     
     
         2 . The air conditioner as claimed in  claim 1 , wherein the controller finishes the defrosting operation of the first outdoor heat exchanger if the refrigerant temperature at the outlet of the first outdoor heat exchanger of which defrosting operation is being performed is higher than a set temperature. 
     
     
         3 . The air conditioner as claimed in  claim 2 , wherein the controller performs defrosting of the second outdoor heat exchanger in succession if the defrosting operation of the first outdoor heat exchanger is finished, and controls the first and second refrigerant flow passage controllers for making the refrigerant passed through the indoor heat exchanger to be introduced only to the first outdoor heat exchanger according to the state of remained charge of the battery or the outdoor temperature. 
     
     
         4 . The air conditioner as claimed in  claim 2 , wherein the controller controls the first and second refrigerant flow passage controllers for controlling flow rates of the refrigerant being introduced to the first and second outdoor heat exchangers according to the state of remained charge of the battery or the outdoor temperature, if the second outdoor heat exchanger does not meet the defrosting operation starting condition after finishing the defrosting operation of the first outdoor heat exchanger. 
     
     
         5 . The air conditioner as claimed in  claim 1 , further comprising a discharged heat recovery unit having a working fluid for circulating at least one of heat generation sources of the battery and a motor to recover discharged heat from the heat generation source. 
     
     
         6 . The air conditioner as claimed in  claim 5 , further comprising a refrigerant heater for heating the refrigerant with the discharged heat of the discharged heat recovery unit,
 wherein the refrigerant heater heats the refrigerant being introduced to the compressor in the defrosting operation, or the refrigerant being introduced to the outdoor heat exchanger.   
     
     
         7 . The air conditioner as claimed in  claim 5 , wherein the discharged heat recovery unit includes a supplementary indoor heat exchanger and a supplementary outdoor heat exchanger connected to make the working fluid having the discharged heat recovered from the heat generation sources to flow therethrough, and
 the controller controls to perform heating with the supplementary indoor heat exchanger and the indoor heat exchanger in general heating operation, and to have the battery to discharge heat through the supplementary outdoor heat exchanger.   
     
     
         8 . The air conditioner as claimed in  claim 7 , wherein the supplementary outdoor heat exchanger is positioned at an outdoor air suction side or an outdoor air discharge side of the outdoor heat exchanger. 
     
     
         9 . The air conditioner as claimed in  claim 8 , wherein, in defrosting operation, the controller heats the room space with the supplementary indoor heat exchanger, and elevates a surrounding air temperature of the outdoor heat exchanger of which defrosting operation is performed with the supplementary outdoor heat exchanger for shortening a defrosting operation time period. 
     
     
         10 . The air conditioner as claimed in  claim 1 , further comprising a by pass pipeline connected between the compressor and each of the outdoor heat exchangers, and a plurality of valves provided to the by pass pipeline, and,
 in defrosting operation, the controller makes a portion of the refrigerant discharged from the compressor to be introduced to the outdoor heat exchanger which is put into defrosting operation, and the other portion of the refrigerant to be introduced to the indoor heat exchanger and the outdoor heat exchanger which performs the heating operation.   
     
     
         11 . The air conditioner as claimed in  claim 1 , wherein the controller controls the first and second refrigerant flow passage controllers to operate the first and second outdoor heat exchangers at the same condition according to the outdoor temperature and a heating load. 
     
     
         12 . The air conditioner as claimed in  claim 1 , wherein, in the heating operation, the controller controls the first and second refrigerant flow passage controllers to make only one, or all, of a plurality of the outdoor heat exchangers is operated according to the remained state of charge in the battery. 
     
     
         13 . The air conditioner as claimed in  claim 1 , wherein the first refrigerant flow passage controller includes a first electronic expansion valve provided between the first outdoor heat exchanger and the indoor heat exchanger,
 the second refrigerant flow passage controller includes a second electronic expansion valve provided between the second outdoor heat exchanger and the indoor heat exchanger, and   the controller opens the first electronic expansion valve, and controls opening of the second electronic expansion valve, if the first outdoor heat exchanger meets the defrosting operation starting condition.