Air conditioner and method of controlling water injection module of air conditioner

Abstract

An air conditioner includes an evaporator in which refrigerant circulates, an expansion valve, a compressor, an evaporative condenser, a water injection module configured to spray water into the evaporative condenser, and a control unit configured to control an operation of the water injection module. The water injection module includes a supply line including a plurality of pressure regulation units configured to regulate a water injection pressure of water supplied to the evaporative condenser to different pressures while passing through a plurality of branch water injection lines branching from a water supply source. Each of the pressure regulation units includes a branch water injection line, a control valve disposed on the branch water injection line, the control valve configured to open and close a flow path of the branch water injection line, and a pressure reducing valve disposed on the branch water injection line.

What is claimed is: 
     
         1 . An air conditioner comprising:
 an evaporator in which refrigerant circulates, an expansion valve, a compressor, an evaporative condenser, a water injection module configured to spray water into the evaporative condenser, and a control unit configured to control an operation of the water injection module,   wherein the water injection module includes:   a supply line including a plurality of pressure regulation units configured to regulate a water injection pressure of water supplied to the evaporative condenser to different pressures while passing through a plurality of branch water injection lines branching from a water supply source,   each of the pressure regulation units includes:   a branch water injection line;   a control valve disposed on the branch water injection line, the control valve configured to open and close a flow path of the branch water injection line; and   a pressure reducing valve disposed on the branch water injection line, and   the control unit is connected to the control valve, and is configured to open one control valve, among a plurality of control valves, and to close a remaining control valve, among the plurality of control valves, according to the number of rotations of the compressor.   
     
     
         2 . The air conditioner of  claim 1 , wherein
 the pressure regulation unit includes:   a first pressure regulation unit including a first branch water injection line, a first control valve disposed on the first branch water injection line, and a first pressure reducing valve configured to reduce the water injection pressure to a first pressure; and   a second pressure regulation unit including a second branch water injection line, a second control valve disposed on the second branch water injection line, and a second pressure reducing valve configured to reduce the water injection pressure to a second pressure, less than the first pressure, and   the control unit is configured to open the first control valve and close the second control valve when the number of rotations of the compressor satisfies a first setting value, and to close the first control valve and open the second control valve when the number of rotations of the compressor satisfies a second setting value, less than the first setting value.   
     
     
         3 . The air conditioner of  claim 2 , wherein the first control valve is formed as a normally open-type valve, and the second control valve is formed as a normally closed-type valve. 
     
     
         4 . The air conditioner of  claim 1 , wherein
 the supply line includes a joining water injection line in which one ends of the branch water injection lines join each other, and   the water injection module includes a discharge unit connected to one end of the joining water injection line, the discharge unit including a water injection nozzle configured to spray water into the evaporative condenser.   
     
     
         5 . The air conditioner of  claim 4 , wherein the discharge unit includes a plurality of discharge lines branching from the one end of the joining water injection line, and the water injection nozzle disposed on the discharge line. 
     
     
         6 . The air conditioner of  claim 5 , wherein the discharge unit includes:
 a first discharge line and a second discharge line branching from the one end of the joining water injection line;   a plurality of first water injection nozzles disposed on the first discharge line, the plurality of first water injection nozzles configured to spray water into a portion of a heat exchange unit of the evaporative condenser; and   a plurality of second water injection nozzles disposed on the second discharge line, the plurality of second water injection nozzles configured to spray water into another portion of the heat exchange unit of the evaporative condenser.   
     
     
         7 . The air conditioner of  claim 1 , wherein the control unit is configured to:
 control an opening and closing operation of the control valve according to the number of rotations of the compressor,   control the opening and closing operation of the control valve in an opening and closing pattern of opening the control valve for a preset water injection time and then closing the control valve for a preset water injection stop time, according to the number of rotations of the compressor.   
     
     
         8 . The air conditioner of  claim 7 , wherein the control unit is configured to repeatedly perform the opening and closing operation of the control valve in a first opening and closing pattern of maintaining the control valve in an open state for a first water injection time and then closing the control valve for a first water injection stop time when the number of rotations of the compressor satisfies a first setting value, and to repeatedly perform the opening and closing operation of the control valve in a second opening and closing pattern of maintaining the control valve in an open state for a second water injection time and then closing the control valve for a second water injection stop time, greater than the first water injection stop time, when the number of rotations of the compressor satisfies a second setting value, less than the first setting value. 
     
     
         9 . The air conditioner of  claim 8 , wherein the first water injection time is set to be equal to or greater than the second water injection time. 
     
     
         10 . A method of controlling a water injection module of an air conditioner, the method comprising:
 a driving start step of starting driving of a compressor according to a preset number of rotations of the compressor;   a determination step of determining an opening and closing operation that is set to open one branch water injection line, among a plurality of branch water injection lines of a water injection module connected to each other in parallel, the plurality of branch water injection lines configured to supply water having a water injection pressure regulated to different pressures, and to close a remaining branch water injection line, among the plurality of branch water injection lines, according to the number of rotations of the compressor; and   a water injection step of injecting water into the heat exchanger by performing the opening and closing operation determined in the determination step.   
     
     
         11 . The method of  claim 10 , wherein
 the branch water injection line includes a first branch water injection line having the water injection pressure regulated to a first pressure, and a second branch water injection line having the water injection pressure regulated to a second pressure, less than the first pressure, and   in the determination step, the opening and closing operation is determined to open the first branch water injection line and close the second branch water injection line when the number of rotations of the compressor satisfies a first setting value, and is determined to open the second branch water injection line and close the first branch water injection line when the number of rotations of the compressor satisfies a second setting value, less than the first setting value.   
     
     
         12 . The method of  claim 10 , further comprising:
 a setting step of setting the number of rotations of the compressor according to outdoor air temperature, before the driving start step.   
     
     
         13 . The method of  claim 11 , wherein
 the determination step includes a determination step of determining whether the number of rotations of the compressor satisfies the first setting value or the second setting value,   in the water injection operation, the determination step of determining whether the number of rotations of the compressor satisfies the first setting value or the second setting value is entered and the determination step of determining the opening and closing operation is re-performed when a predetermined condition is satisfied, and a current state is maintained when the predetermined condition is not satisfied.   
     
     
         14 . A method of controlling a water injection module of an air conditioner, the method comprising:
 a driving start step of starting driving a of compressor according to the set number of rotations of the compressor;   a determination step of determining an opening and closing pattern of injecting water into a heat exchanger through a supply line of a water injection module for a preset water injection time and then stopping water injection for a preset water injection stop time, according to the number of rotations of the compressor; and   an operation step of performing a water injection operation and a water injection stop operation of the water injection the opening and closing pattern determined in the determination step.   
     
     
         15 . The method of  claim 14 , wherein
 in the determination step,   when the number of rotations of the compressor satisfies a first setting value, the opening and closing pattern is determined as a first opening and closing pattern of injecting water for a first water injection time and then stopping water injection for a first water injection stop time, and   when the number of rotations of the compressor satisfies a second setting value, less than the first setting value, the opening and closing pattern is determined as a second opening and closing pattern of injecting water for a second water injection time, less than or equal to the first water injection time, and then stopping water injection for a second water injection stop time, greater than the first water injection stop time.   
     
     
         16 . The method of  claim 14 , wherein, in the operation step, the water injection operation and the water injection stop operation of the water injection module are repeatedly performed in the opening and closing pattern determined in the determination step. 
     
     
         17 . The method of  claim 15 , further comprising:
 a setting step of setting the number of rotations of the compressor according to outdoor air temperature, before the driving start step.   
     
     
         18 . The method of  claim 15 , wherein
 the determination step includes a determination step of determining whether the number of rotations of the compressor satisfies the first setting value or the second setting value,   in the operation step, the determination step of determining whether the number of rotations of the compressor satisfies the first setting value or the second setting value is entered and the determination step of determining the opening and closing operation is re-performed when a predetermined condition is satisfied, and a current state is maintained when the predetermined condition is not satisfied.