| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce influence in fracture of a vacuum heat insulating material by disposing a plurality of vacuum heat insulating materials independently sealed around a hot water storage tank, and to easily dispose the vacuum heat insulating materials on the hot water storage tank while keeping heat insulating performance. <P>SOLUTION: The plurality of divided vacuum heat insulating materials 31a, 31b, 31c are arranged in the longitudinal direction of the hot water storage tank, for example, in a state of being constituted by covering a core material part 31a with a laminate film 31a1 to seal it in vacuum, and forming a projecting portion, and the core material portion has a gradient so that its upper portion is thickened and its lower portion is thinned to improve heat insulating heat retaining performance of the upper portion of the hot water storage tank 30. As the vacuum heat insulating materials are disposed to cover the circumference of the hot water storage tank 30 approximately in the cylindrical shape, the workability in covering the circumference of the hot water storage tank 30 by the vacuum heat insulating materials 31a, 31b, 31c can be improved, and a degree of influence in fracture of the vacuum heat insulating materials 31a, 31b, 31c can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT |
