Air conditioner

Abstract

An air conditioner includes a refrigerant circuit that is formed by connecting an indoor unit to an outdoor unit, where the circuit is filled with a predetermined amount of a refrigerant. The conditioner includes an obtainer that regularly acquires an operating state quantity at a time of air conditioning operation, a storage that stores therein the quantity that is acquired, a model that estimates a refrigerant remaining amount in the circuit by using the quantity, a detector that detects one of a first quantity being an operating state quantity in a state in which the circuit meets a first condition and a second quantity being an operating state quantity in a state in which the circuit meets a second condition that is different from the first condition, and a controller that estimates the remaining refrigerant amount in the circuit by using the model and the detected quantity.

1 . An air conditioner that includes a refrigerant circuit that is formed by connecting, by a refrigerant pipe, an indoor unit including an indoor heat exchanger to an outdoor unit including a compressor, an outdoor heat exchanger, and an expansion valve, the refrigerant circuit being filled with a predetermined amount of a refrigerant, the air conditioner comprising:
 a memory storing an estimation model that estimates a refrigerant remaining amount in the refrigerant circuit by using the operating state quantity,   and processing circuitry coupled to the memory and configured to:   regularly acquire an operating state quantity at a time of air conditioning operation;   store therein the operating state quantity that is acquired by the acquiring;   detect, from the storing, one of a first operating state quantity and a second operating state quantity, the first operating state quantity being an operating state quantity in a state in which the refrigerant circuit meets a first stability condition, the second operating state quantity being an operating state quantity in a state in which the refrigerant circuit meets a second stability condition that is different from the first stability condition; and   estimate the remaining refrigerant amount in the refrigerant circuit by using the estimation model and the operating state quantity that is detected by the detecting.   
     
     
         2 . The air conditioner according to  claim 1 , wherein the second stability condition is a mild condition as compared to the first stability condition. 
     
     
         3 . The air conditioner according to  claim 1 , wherein the estimating includes:
 estimating the remaining refrigerant amount by using the first operating state quantity and the estimation model if number of detections of the first operating state quantity detected by the detecting in a predetermined period is equal to or larger than a predetermined value, and   estimating the remaining refrigerant amount by using the second operating state quantity and the estimation model if the number of detections of the first operating state quantity detected by the detecting in the predetermined period is smaller than the predetermined value.   
     
     
         4 . The air conditioner according to  claim 1 , wherein the detecting includes:
 adopting, as the first operating state quantity, the operating state quantity that is detected in a state in which the first stability condition is met, the state being a state in which variation of a rotation speed of the compressor falls within a first predetermined range for a first predetermined period or more, and   adopting, as the second operating state quantity, the operating state quantity that is detected in a state in which the second stability condition is met, the state being a state in which the variation of the rotation speed of the compressor falls within a second predetermined range that exceeds the first predetermined range for the first predetermined period or more or for a second predetermined period or more, the second predetermined period exceeding the first predetermined period.   
     
     
         5 . The air conditioner according to  claim 4 , wherein the detecting includes adopting, as the first operating state quantity, the operating state quantity that is detected in a state in which the first stability condition is met, the state being a state in which an absolute value of a difference between refrigerant discharge temperature and target discharge temperature of the compressor is equal to or smaller than a predetermined value for the first predetermined period or more, in addition to when the first condition is met. 
     
     
         6 . The air conditioner according to  claim 1 , wherein the detecting includes detecting the first operating state quantity and the second operating state quantity. 
     
     
         7 . The air conditioner according to  claim 1 , wherein if the estimating includes estimating the remaining refrigerant amount by using the second operating state quantity and the estimation model at each predetermined timing, the estimating includes outputting, as the remaining refrigerant amount in the predetermined period, an average value of the remaining refrigerant amounts that are estimated at the respective predetermined timings in the predetermined period.