AIR CONDITIONER

• Main Authors: TAKAOKA AKIRA, SANADA SHINTARO, TAKANO KENICHI, TAKEUCHI HIROTOSHI
• Format: Patent
• Language: English; Japanese
• Published: 25.01.2018
• Subjects: BLASTING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; HEATING; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; MANUFACTURE OR STORAGE OF ICE; MECHANICAL ENGINEERING; REFRIGERATION MACHINES, PLANTS OR SYSTEMS; REFRIGERATION OR COOLING; WEAPONS

PROBLEM TO BE SOLVED: To provide an air conditioner capable of correctly determining whether frosting on an outdoor heat exchanger abruptly progresses.SOLUTION: A CPU 210 determines whether a second frosting condition is established. Specifically, the CPU 210 reads a heat exchange exit temperature Teo stored in a storage part 220 in time series, and determines whether a current heat exchange exit temperature Teo is equal to or lower than a second threshold temperature, a rate of decrease in heat exchange exit temperature calculated using the latest heat exchange exit temperature Teo and the heat exchange exit temperature right before it is equal to or larger than a predetermined rate of decrease, and whether the number of times of increase in the number of operation units of indoor units 5a to 5c while two successive heat exchange exit temperatures are stored is equal to or larger than the predetermined number of times. Then, when a second frosting condition is established, the CPU 210 switches a four-way valve 22 and executes defrosting operation preparation processing making a refrigerant circuit 10 a cooling cycle, restarts a compressor 21 when the defrosting operation preparation processing is completed, and starts defrosting operation.SELECTED DRAWING: Figure 1 【課題】室外熱交換器で急激に着霜が進行しているか否かを誤りなく判断できる空気調和装置を提供する。【解決手段】ＣＰＵ２１０は、第２着霜条件が成立しているか否かを判断する。具体的には、ＣＰＵ２１０は、時系列で記憶部２２０に記憶した熱交出口温度Ｔｅｏを読み出し、現在の熱交出口温度Ｔｅｏが第２閾温度以下であるか否か、かつ、最新の熱交出口温度Ｔｅｏと１つ前の熱交出口温度Ｔｅｏを用いて算出した熱交出口温度の低下率が所定低下率以上か否か、かつ、連続する２つの熱交出口温度を記憶する間に室内機５ａ〜５ｃの運転台数が増加した回数が所定回数以上となったかを判定する。そして、第２着霜条件が成立していれば、ＣＰＵ２１０は、四方弁２２を切り替えて冷媒回路１０を冷房サイクルとする除霜運転準備処理を実行し、除霜運転準備処理が完了すれば圧縮機２１を再起動して除霜運転を開始する。【選択図】図１