| 摘要 |
<p>Provided is a vehicle air-conditioning device capable of reliably removing frost adhering to an outdoor heat exchanger without increasing the number of components and the occupied space. When it is determined during a heating operation that environmental conditions under which frost forms on an outdoor heat exchanger (22) are met, a hot gas defrosting operation, in which a hot gas circuit for inflow into the outdoor heat exchanger is opened and an opening/closing valve between the refrigerant outflow side of the outdoor heat exchanger and the refrigerant inflow side of an accumulator is closed after the hot gas circuit is opened, is performed. Consequently, the heat radiation amount in the outdoor heat exchanger (22) can be increased while the interior of the outdoor heat exchanger (22) is in a high-temperature and high-pressure state, thereby making it possible to reliably remove frost adhering to the outdoor heat exchanger (22).</p> |
