Heating-medium heating unit and vehicle air conditioner using the same

Abstract

In a heating-medium heating unit equipped with a first heating-medium circulation box and a second heating-medium circulation box which are in close contact with both surfaces of a PTC heater, in which heating-medium circulation passages are formed in the interior, and which are joined to each other in a liquidtight manner, wherein joining surfaces are sealed with liquid gaskets, the heating-medium circulation passages are provided with joining-surface cooling channels that cool the joining surface which is sealed with a liquid gasket and on which the heat from the PTC heater acts. The joining-surface cooling channels are provided at positions closer to the joining surface than to the PTC heater.

1 . A heating-medium heating unit, comprising:
 a flat PTC heater;   a first heating-medium circulation box in which a plurality of box components are stacked one on another, which is in close contact with one surface of the PTC heater, and in which a heating-medium circulation passage is formed in the interior; and   a second heating-medium circulation box in which a plurality of box components are similarly stacked on one another, which is in close contact with the other surface of the PTC heater, in which a heating-medium circulation passage is formed in the interior, and which is joined to the first heating-medium circulation box in a liquidtight manner,   wherein a heating medium that circulates through the heating-medium circulation passages in the first and second heating-medium circulation boxes is heated by heat radiated from both surfaces of the PTC heater,   wherein PTC modules that constitute the PTC heater are disposed in a plurality of rows along the channel direction of the heating-medium circulation passages, the plurality of PTC modules have different widths, and ON/OFF states of the PTC modules can be individually controlled.   
     
     
         2 . A vehicle air conditioner including a blower that circulates outside air or vehicle interior air, a cooler provided downstream of the blower, and a radiator provided downstream of the cooler,
 wherein a heating medium heated by the heating-medium heating unit according to  claim 1  can circulate through the radiator.