Refrigerant evaporator

A refrigerant evaporator that exchanges heat between fluid flowing outside to be cooled and refrigerant, comprising

• a first evaporation unit and a second evaporation unit disposed in series in a flow direction of the fluid, wherein:
• each of the first evaporation unit and the second evaporation unit has
• a heat-exchanging core portion in which a plurality of tubes are stacked, the refrigerant flowing through the plurality of tubes, and
• a pair of tank portions connected to both ends of the plurality of tubes to collect or distribute the refrigerant flowing through the plurality of tubes;
• the heat-exchanging core portion of the first evaporation unit has a first core portion defined by a part of the plurality of tubes and a second core portion defined by a rest of the plurality of tubes;
• the heat-exchanging core portion of the second evaporation unit has a third core portion defined by a part of the plurality of tubes opposing at least a part of the first core portion in the flow direction of the fluid and a fourth core portion defined by a part of the plurality of tubes opposing at least a part of the second core portion in the flow direction of the fluid;
• of the pair of tank portions of the first evaporation unit, one tank portion includes a first refrigerant collection portion to collect the refrigerant from the first core portion and a second refrigerant collection portion to collect the refrigerant from the second core portion;
• of the pair of tank portions of the second evaporation unit, one tank portion includes a first refrigerant distribution portion to distribute the refrigerant to the third core portion and a second refrigerant distribution portion to distribute the refrigerant to the fourth core portion;
• the first evaporation unit and the second evaporation unit are coupled via a first communication portion that introduces the refrigerant in the first refrigerant collection portion to the second refrigerant distribution portion and a second communication portion that introduces the refrigerant in the second refrigerant collection portion to the first refrigerant distribution portion;
• an intermediate tank portion through which refrigerant flows is connected to an outer surface of the one tank portion of the first evaporation unit and an outer surface of the one tank portion of the second evaporation unit;
• a tank external refrigerant space through which refrigerant flows is defined by an outer wall of the one tank portion of the first evaporation unit, an outer wall of the one tank portion of the second evaporation unit, and an outer wall of the intermediate tank portion;
• and
• the intermediate tank portion defines the first communication portion and the tank external refrigerant space defines the second communication portion.