Protection method and device for high-temperature prevention during heating and refrigerant shortage during heating, and air conditioning system

Abstract

The present invention provides a protection method and device for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system. The method comprises: in a heating mode, starting an outdoor fan, and detecting an outdoor ambient temperature, an exhaust temperature of a compressor, a fan current of the outdoor fan and an operating duration of the outdoor fan in real time; when the operating duration is greater than a first preset duration, comparing whether the sum of the exhaust and a compensation temperatures is greater than a first preset temperature and whether the fan current is greater than a preset current value; if yes, controlling the outdoor fan to stop operating and an indoor unit to operate normally.

1 . A protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system, wherein the air conditioning system comprises an indoor unit and an outdoor unit and the outdoor unit at least comprises a compressor and an outdoor fan, the protection method comprising the following steps:
 a detection step: in a heating mode, starting the outdoor fan, and detecting an outdoor ambient temperature, an exhaust temperature of the compressor, a fan current of the outdoor fan and an operating duration of the outdoor fan in real time;   a high-temperature prevention determination step: when the operating duration is greater than a first preset duration, comparing whether the sum of the exhaust temperature and a compensation temperature is greater than a first preset temperature and whether the fan current is greater than a preset current value: wherein the compensation temperature is associated with the outdoor ambient temperature;   a high-temperature prevention protection entry step: when the sum of the exhaust temperature and the compensation temperature is greater than the first preset temperature and the fan current is greater than the preset current value, controlling the outdoor fan to stop operating and the indoor unit to operate normally;   a refrigerant shortage determination step: after the outdoor fan stops operating, determining whether the sum of the exhaust temperature and the compensation temperature is greater than a second preset temperature for a second duration; and   a refrigerant shortage protection entry step: when the sum of the exhaust temperature and the compensation temperature is greater than the second preset temperature for the second duration, controlling the compressor to stop and reporting a fault.   
     
     
         2 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 1 , wherein the air conditioning system is a fixed-frequency air conditioning system without indoor unit and outdoor unit communication. 
     
     
         3 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 2 , wherein in the high-temperature prevention determination step, the association of the compensation temperature with the outdoor ambient temperature comprises:
 when the outdoor ambient temperature is greater than a first temperature threshold, the compensation temperature is a first compensation temperature;   when the outdoor ambient temperature is greater than a second temperature threshold and less than or equal to the first temperature threshold, the compensation temperature is a second compensation temperature; and   when the outdoor ambient temperature is less than or equal to the second temperature threshold, the compensation temperature is a third compensation temperature, and the first temperature threshold is greater than the second temperature threshold.   
     
     
         4 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 3 , wherein in the refrigerant shortage determination step, the second preset temperature ranges from 90° C. to 110° C. 
     
     
         5 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 3 , wherein the outdoor unit further comprises an outdoor heat exchanger; and the protection method further comprises:
 an outdoor fan start control step: determining whether the outdoor fan meets an outdoor fan starting condition; if yes, starting the outdoor fan, and if no, returning to the high-temperature prevention protection entry step; wherein the outdoor fan starting condition comprises:   the shutdown duration of the outdoor fan is greater than a third preset duration;   the sum of the exhaust temperature and the compensation temperature is less than a third preset temperature, and the third preset temperature is less than the first preset temperature;   or the difference between the outdoor ambient temperature and an outlet temperature of the outdoor heat exchanger is greater than a first temperature difference threshold.   
     
     
         6 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 5 , wherein the third preset duration ranges from 3 to 10 min. 
     
     
         7 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 5 , wherein the third preset temperature ranges from 70° C. to 90° C. 
     
     
         8 . The protection method for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 5 , wherein the first temperature difference threshold ranges from 10° C. to 40° C. 
     
     
         9 . A protection device for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system, comprising:
 a detection module, configured to: in a heating mode and under the condition that an outdoor fan is started, detect an outdoor ambient temperature, an exhaust temperature of the compressor, a fan current of the outdoor fan and an operating duration of the outdoor fan in real time;   a high-temperature prevention determination module, configured to: when the operating duration is greater than a first preset duration, compare whether the sum of the exhaust temperature and a compensation temperature is greater than a first preset temperature and whether the fan current is greater than a preset current value; wherein the compensation temperature is associated with the outdoor ambient temperature;   a high-temperature prevention protection entry module, configured to: when the sum of the exhaust temperature and the compensation temperature is greater than the first preset temperature and the fan current is greater than the preset current value, control the outdoor fan to stop operating and the indoor unit to operate normally;   a refrigerant shortage determination module, configured to: after the outdoor fan stops operating, determine whether the sum of the exhaust temperature and the compensation temperature is greater than a second preset temperature for a second duration; and   a refrigerant shortage protection entry module, configured to: when the sum of the exhaust temperature and the compensation temperature is greater than the second preset temperature for the second duration, control the compressor to stop and report a fault.   
     
     
         10 . An air conditioning system, comprising the protection device for high-temperature prevention during heating and refrigerant shortage during heating of an air conditioning system according to  claim 9 .