Air conditioner

Abstract

An air conditioner performs a refrigerant quantity judging operation to judge the refrigerant quantity in a refrigerant circuit, and includes a heat source unit, utilization units, expansion mechanisms, a first refrigerant gas pipe, a second refrigerant gas pipe, a refrigerant liquid pipe, switching mechanisms, bypass circuits, bypass circuit opening/closing element, and a controller. The switching mechanism can switch between a first state and a second state. The bypass circuit opening/closing element are provided in the bypass circuits that bypass the first refrigerant gas pipe to the second refrigerant gas pipe, and open and close the bypass circuits. The controller opens the bypass circuit opening/closing element before performing the refrigerant quantity judging operation.

1 . An air conditioner that performs a refrigerant quantity judging operation to judge the refrigerant quantity in a refrigerant circuit, the air conditioner comprising:
 a heat source unit including a heat source side heat exchanger and a compression element configured to compress refrigerant gas;   a utilization unit including a utilization side heat exchanger;   an expansion mechanism;   a first gas refrigerant pipe extending from a discharge side of the compression element to the utilization unit;   a second gas refrigerant pipe extending from a suction side of the compression element to the utilization unit;   a liquid refrigerant pipe extending from the heat source side heat exchanger to the utilization unit;   a switching mechanism configured to switch between a first state and a second state, the refrigerant flowing through the liquid refrigerant pipe evaporating in the utilization side heat exchanger and thereafter flowing into the second gas refrigerant pipe in the first state, and the refrigerant flowing through the first gas refrigerant pipe condensing in the utilization side heat exchanger and thereafter flowing into the liquid refrigerant pipe in the second state;   a bypass circuit configured to bypass the first gas refrigerant pipe to the second gas refrigerant pipe;   a bypass circuit opening/closing element provided in the bypass circuit and configured to open and close the bypass circuit; and   a controller configured to open the bypass circuit opening/closing element before performing the refrigerant quantity judging operation.   
   
   
       2 . The air conditioner according to  claim 1 , wherein
 the bypass circuit opening/closing element is provided in the heat source unit.   
   
   
       3 . The air conditioner according to  claim 1 , further comprising
 a switching unit separate from the utilization unit and the heat source unit, the switching unit including the switching mechanism, and   the bypass circuit opening/closing element being provided in the switching unit.   
   
   
       4 . The air conditioner according to  claim 1 , further comprising
 a temperature detecting element configured to detect the refrigerant temperature in the first gas refrigerant pipe and output a refrigerant temperature detection value, and   the controller corrects the refrigerant quantity judged by the refrigerant quantity judging operation based on the refrigerant temperature detection value.   
   
   
       5 . The air conditioner according to  claim 4 , wherein
 the temperature detecting element is provided in the switching unit.   
   
   
       6 . The air conditioner according to  claim 4 , wherein
 the temperature detecting element is provided in the heat source unit.   
   
   
       7 . The air conditioner according to  claim 5 , wherein
 the temperature detecting element is provided in the heat source unit.   
   
   
       8 . The air conditioner according to  claim 2 , further comprising
 a switching unit separate from the utilization unit and the heat source unit, the switching unit including the switching mechanism, and   the bypass circuit opening/closing element being provided in the switching unit.   
   
   
       9 . The air conditioner according to  claim 8 , further comprising
 a temperature detecting element configured to detect the refrigerant temperature in the first gas refrigerant pipe and output a refrigerant temperature detection value, and   the controller corrects the refrigerant quantity judged by the refrigerant quantity judging operation based on the refrigerant temperature detection value.   
   
   
       10 . The air conditioner according to  claim 9 , wherein
 the temperature detecting element is provided in the switching unit.   
   
   
       11 . The air conditioner according to  claim 9 , wherein
 the temperature detecting element is provided in the heat source unit.   
   
   
       12 . The air conditioner according to  claim 2 , further comprising
 a temperature detecting element configured to detect the refrigerant temperature in the first gas refrigerant pipe and output a refrigerant temperature detection value, and   the controller corrects the refrigerant quantity judged by the refrigerant quantity judging operation based on the refrigerant temperature detection value.   
   
   
       13 . The air conditioner according to  claim 12 , wherein
 the temperature detecting element is provided in the switching unit.   
   
   
       14 . The air conditioner according to  claim 12 , wherein
 the temperature detecting element is provided in the heat source unit.   
   
   
       15 . The air conditioner according to  claim 3 , further comprising
 a temperature detecting element configured to detect the refrigerant temperature in the first gas refrigerant pipe and output a refrigerant temperature detection value, and   the controller corrects the refrigerant quantity judged by the refrigerant quantity judging operation based on the refrigerant temperature detection value.   
   
   
       16 . The air conditioner according to  claim 15 , wherein
 the temperature detecting element is provided in the switching unit.   
   
   
       17 . The air conditioner according to  claim 15 , wherein
 the temperature detecting element is provided in the heat source unit.