| 摘要 |
PURPOSE:To sense the appropriate signal for starting defrosting and consequently contrive to improve SEER, manifestation of heating capacity and reliability by a method wherein means to detect the dry-bulb temperature, relative humidity of the outside air and the depressed pressure are provided. CONSTITUTION:The range A surrounded by points 20, 21, 22 and 23 in the attached figure shows the frosting range. A temperature controller 9 for controlling defrosting detects the dry-bulb temperature, wet-bulb temperature and low pressure in said range A and has an actuation characteristic to enable to issue a ''no defrosting necessary'' signal, when the dry-bulb temperature and relative humidity under the low pressure P3 are below the constant low pressure P3 curve, while to issue a ''defrosting start'' signal, when said temperature and humidity are above the constant P3 curve. The dry-bulb temperatures and relative humidities of the outside air are set and programmed with respect to the low pressures P1-Pn and inputted to the temperature controller 9 so as to judge the necessity of defrosting by comparing the respective inputted data of low pressure, dry-bulb temperature and wet-bulb temperature of the outside air with the pre-inputted values corresponding to said data in order to control a four-way valve by means of resultant output signal and to control the actuation of defrosting operation. |
