Vehicular heat management system

A vehicular heat management system, comprising:

• a compressor arranged on a heat pump type refrigerant circulation line;
• a high-pressure side heat exchanger arranged on the heat pump type refrigerant circulation line;
• an outdoor heat exchanger arranged on the heat pump type refrigerant circulation line;
• a low-pressure side heat exchanger arranged on the heat pump type refrigerant circulation line;
• a first expansion valve arranged on the upstream side of the outdoor heat exchanger;
• a second expansion valve arranged on the downstream side of the outdoor heat exchanger;
• and
• a control part configured to control opening degrees of the first expansion valve and the second expansion valve depending on whether icing occurs in the outdoor heat exchanger under a heat pump mode condition,
• wherein the control part is configured to enter a dual expansion mode in which a refrigerant is expanded by the first expansion valve and the second expansion valve if the control part determines that icing occurs in the outdoor heat exchanger, and enter a single expansion mode in which a refrigerant is expanded by only one of the first expansion valve and the second expansion valve if the control part determines that icing does not occur in the outdoor heat exchanger,
• wherein the control part is configured to, in the single expansion mode, fully open the second expansion valve on the downstream side of the outdoor heat exchanger and control the opening degree of the first expansion valve on the upstream side of the outdoor heat exchanger to adjust a refrigerant flow rate on the side of the outdoor heat exchanger, and
• wherein the control part is configured to, in the dual expansion mode, control the opening degrees of the first expansion valve and the second expansion valve to adjust the refrigerant flow rate on the side of the outdoor heat exchanger in a decreasing direction so that the temperature of the outdoor heat exchanger is increased to cope with occurrence of icing.