Vehicle air conditioning system
A vehicle air conditioning system includes: an air conditioning duct through which air can flow; an evaporator disposed in the air conditioning duct; and a humidity control device disposed on an upstream side of the evaporator in the air conditioning duct. The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from a first end face to a second end face to form a flow path, at least the partition walls being made of a material having a PTC property; and a dehumidifying layer formed on a surface of each of the partition walls.
1 . A vehicle air conditioning system, comprising:
an air conditioning duct through which air can flow;
an evaporator disposed in the air conditioning duct; and
a humidity control device disposed on an upstream side of the evaporator in the air conditioning duct,
wherein the humidity control device comprises: a honeycomb structure comprising an outer peripheral wall and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from a first end face to a second end face to form a flow path, at least the partition walls being made of a material having a positive temperature coefficient (PTC) property; and a dehumidifying layer formed on a surface of each of the partition walls.
2 . The vehicle air conditioning system according to claim 1 ,
wherein the air conditioning duct has a first path for allowing the air to flow into the evaporator and a second path for discharging the air to a vehicle exterior, between the evaporator and the humidity control device, and
wherein the air conditioning system further comprises a switching valve capable of switching the flow of the air between the first path and the second path.
3 . The vehicle air conditioning system according to claim 1 , wherein the material having the PTC property has a Curie point of 80 to 200° C.
4 . The vehicle air conditioning system according to claim 1 , wherein the humidity control device further comprises a pair of electrodes provided on the honeycomb structure.
5 . The vehicle air conditioning system according to claim 4 , wherein the humidity control device further comprises terminals connected to the pair of electrodes.
6 . The vehicle air conditioning system according to claim 1 , wherein the material having the PTC property is made of a material comprising barium titanate as a main component, the material being substantially free of lead.
7 . The vehicle air conditioning system according to claim 1 , wherein the material having the PTC property has a volume resistivity of 0.5 to 30 Ω·cm at 25° C.
8 . The vehicle air conditioning system according to claim 1 , wherein the honeycomb structure has a thickness of the partition wall of 0.30 mm or less, a cell density of 100 cells/cm 2 or less, and a cell pitch of 1.0 mm or more.
9 . The vehicle air conditioning system according to claim 1 , wherein the honeycomb structure has a thickness of the partition wall of 0.08 to 0.36 mm, a cell density of 2.54 to 140 cells/cm 2 , and an opening ratio of the cells of 0.70 or more.
10 . The vehicle air conditioning system according to claim 1 , wherein the dehumidifying layer comprises a dehumidifying material.
11 . The vehicle air conditioning system according to claim 1 , wherein the dehumidifying layer comprises a functional material having a function of adsorbing carbon dioxide and/or volatile components.
12 . The vehicle air conditioning system according to claim 1 , wherein the dehumidifying layer comprises a catalyst.