Method for controlling cooling/heating of heat pump system

Abstract

Disclosed is a method for controlling cooling/heating of a heat pump system comprising the steps of: (a) controlling a compressor so that a flow rate of a refrigerant is reduced when the heat pump system is switched from a cooling mode to a heating mode or from the heating mode to the cooling mode; and (b) controlling a four-way valve so that a flow direction of the refrigerant is converted into an opposite direction when the flow rate of the refrigerant is reduced after the step (a). The method prevents the rapid change of the flow direction of the refrigerant during the cooling/heating mode switching and reduces noise generated in the cooling/heating mode switching.

What is claimed is:  
     
         1 . A method for controlling cooling/heating of a heat pump system, comprising the steps of: 
 (a) controlling a compressor so that a flow rate of a refrigerant is reduced when the heat pump system is switched from a cooling mode to a heating mode or from the heating mode to the cooling mode; and    (b) controlling a four-way valve so that a flow direction of the refrigerant is changed into an opposite direction when the flow rate of the refrigerant after the step (a) is reduced.    
     
     
         2 . The method as set forth in  claim 1 , 
 wherein a power supply to the compressor is switched off in the step (a) so that the flow rate of the refrigerant is reduced.    
     
     
         3 . The method as set forth in  claim 2 , 
 wherein a power supply to the compressor is switched on after the step (b).    
     
     
         4 . The method as set forth in  claim 1 , 
 wherein the operation of the compressor is converted into a stage having a lower state than that of a stage at a point of time when the heat pump system is switched from the cooling mode to the heating mode or from the heating mode to the cooling mode so that the flow rate of the refrigerant is reduced.    
     
     
         5 . The method as set forth in  claim 4 , further comprising the step of (c) controlling the compressor to re-operate in a normal state after the step (b).  
     
     
         6 . The method as set forth in  claim 1 , 
 wherein the four-way valve in the step (b) is controlled to convert the flow direction of the refrigerant into the opposite direction, in case that a designated time from the step (a) has elapsed.    
     
     
         7 . The method as set forth in  claim 1 , 
 wherein the four-way valve in the step (b) is controlled to convert the flow direction of the refrigerant into the opposite direction, in case that the flow rate of the refrigerant is reduced to less than a designated rate.    
     
     
         8 . The method as set forth in  claim 1 , 
 wherein the four-way valve in the step (b) is controlled to convert the flow direction of the refrigerant into the opposite direction, in case that the flow rate of the refrigerant reaches zero (0).    
     
     
         9 . The method as set forth in  claim 1 , 
 wherein the four-way valve in the step (b) is controlled such that power is supplied to the four-way valve when the heat pump system is switched from the cooling mode to the heating mode, and a power supply to the four-way valve is cut off when the heat pump system is switched from the heating mode to the cooling mode.    
     
     
         10 . A method for controlling cooling/heating of a heat pump system comprising the steps of: 
 (a) stopping a compressor when the heat pump system is switched from a cooling mode to a heating mode or from the heating mode to the cooling mode;    (b) operating a four-way valve so as to convert a flow direction of the refrigerant after a designated time from the stoppage of the compressor in the step (a) elapses; and    (c) re-operating the compressor after the step (b).