Membrane humidifier for fuel cell

1. A membrane humidifier comprising:

buffering and spacing structures each interposed between adjacent hollow fiber membranes of a plurality of hollow fiber membranes arranged in a housing of the membrane humidifier,

wherein the buffering and spacing structures are arranged such that a largest number of buffering and spacing structures is arranged at a central side, and a gradually reduced number of buffering and spacing structures is arranged toward a peripheral side, and

wherein the buffering and spacing structures buffer a pressure of air supplied from an air blower and maintain a spacing to form a flow channel for humid air between the adjacent hollow fiber membranes.

2. The membrane humidifier of claim 1 , wherein the buffering and spacing structures comprise a hydrophilic material.

3. The membrane humidifier of claim 1 , wherein the buffering and spacing structures have a greater diameter than the hollow fiber membranes, and have a length equal to a length of the hollow fiber membranes.

4. The membrane humidifier of claim 1 , wherein the buffering and spacing structures have a shape selected from the group comprising a straight shape, a zig-zag shape, a protrusion/groove shape, a coil spring shape, a crimp shape, and a mesh roll shape.

5. The membrane humidifier of claim 1 , wherein opposite ends of the buffering and spacing structures are potted together with opposite ends of the hollow fiber membranes, using a potting material.

6. The membrane humidifier of claim 1 , wherein humid air guide holes are formed at each of the buffering and spacing structures in a radial direction of the buffering and spacing structure.

7. The membrane humidifier of claim 1 , wherein humid air grooves are formed at each of the buffering and spacing structures in a radial direction of the buffering and spacing structure.