BEST MODE FOR CARRYING OUT THE INVENTION
[0039] Now, with reference to FIG. 5 , the first embodiment of the present invention will be described herein.
[0040] FIG. 5 corresponds to FIG. 2 described above. In FIG. 5 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . In this embodiment, the flange 43 a is bent at the middle portion outward with the upper and lower end portions 37 a which is joined to the flange 43 a . The flange 43 a and the upper and lower end portions 37 a are bent substantially parallel with the upper and lower portions 43 b , 43 c of the housing body 43 or substantially perpendicular to the side wall plate 37 , to form a heat deformation absorbing mechanism 47 .
[0041] The flange 43 a and the upper and lower end portions 37 a are joined at the heat deformation absorbing mechanism 47 by welding, brazing or nuts and bolts. Mainly, the flange 43 a and the upper and lower end portions 37 a are joined at the parallel portion of the heat deformation absorbing mechanism 47 with the upper and lower portions 43 b , 43 c.
[0042] In this heat exchanger, when high temperature gas flows in the high temperature fluid channel of the core 5 , the heat exchange section 1 rises in temperature at its central portion more than its peripheral portions to produce thermal expansion. Due to this thermal expansion, the upper and lower portions 43 b , 43 c of the heat exchange section 1 are apt to bulge. However, the bulging force is suppressed by the heat deformation absorbing mechanism 47 composed of flange 43 a and the upper and lower end portions 37 a , so that the upper and lower portion portions 43 b , 43 c are prevented from deforming.
[0043] Since the deformation of the upper and lower portions 43 b , 43 c can be prevented, the joint strength of the heat deformation absorbing mechanism 47 can be secured and the deformation of the side wall plate 37 can be prevented, thus durability of the housing 3 can be improved.
[0044] FIGS. 6 and 7 show the second embodiment of the present invention. FIG. 6 corresponds to FIG. 2 described above. In FIGS. 6 and 7 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . In this embodiment, a wave form portion 49 as a heat deformation absorbing mechanism is formed on the part of the upper and lower portions 43 b , 43 c of the housing body 43 . The wave form portion 49 corresponds to the heat resistant filler 45 .
[0045] The wave form portion 49 has a wave form of repeated projections and a recesses in rightward and leftward directions in FIGS. 6 and 7 . The inner face of the recess is aligned with the inner face of the upper and lower portions 43 b , 43 c . Thus, it is easier to insert the heat exchange section 1 covered by the heat resistant filler 45 into the housing body 3 . The arrangement described above can be changed in accordance with the elasticity of the heat resistant filler 45 and rigidity of the housing 3 .
[0046] In the second embodiment, due to this thermal expansion, the heat exchange section 1 is apt to bulge the upper and lower portions 43 b , 43 c . However, the bulging force is absorbed by the elastic deformation of the wave form portion 49 . Thus, the upper and lower portion portions 43 b , 43 c are prevented from deforming. Since the deformation of the upper and lower portions 43 b , 43 c can be prevented, the joint strength of the heat deformation absorbing mechanism 47 can be secured and the deformation of the side wall plate 37 can be prevented, thus durability of the housing 3 can be improved.
[0047] FIG. 8 shows the third embodiment of the present invention. FIG. 8 corresponds to FIG. 2 described above. An arrow in FIG. 8 designates the flow direction of high temperature gas. In FIG. 8 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . In this embodiment, a wave form portion 51 is provided instead of the wave form portion 49 described above. The wave form portion 51 has large projections and large recesses on the lower portion in FIG. 8 into which high temperature gas flows and small projections and small recesses on the upper portion in FIG. 8 from which high temperature gas flows. More concretely, the width or the height of the waves can be changed in the flow direction of high temperature gas. Only one of width and height may be changed.
[0048] The temperature on the inlet side of high temperature gas is higher than that on the outlet side of the high temperature gas. Accordingly, the thermal expansion on the inlet side of high temperature gas is larger than that on the outlet side of the high temperature gas. As described above, it is possible to deal with the thermal expansion in accordance with the temperature change by making the wave form portion 51 on the inlet side of high temperature gas larger. Thus, the deformation of the joint portion of flange 43 a of the housing body 43 and the upper and lower end portions 37 a of the side wall plate 37 and the deformation of the side wall plates 37 can be efficiently prevented. Thus, the joint strength of the joint portion can be secured, so that the durability of the housing 3 can be improved.
[0049] FIG. 9 shows the fourth embodiment of the present invention. FIG. 9 corresponds to FIG. 2 described above. In FIG. 9 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . In this embodiment, the heat resistant filler 53 has a short length in the flow direction of high temperature gas and arranged only on the downstream side of high temperature gas. A wave form portion 55 is formed on the part of the upper and lower portions 43 b , 43 c of the housing body 43 . The wave form portion 55 is arranged in accordance with the heat resistant filler 53 .
[0050] The temperature on the upstream side of high temperature gas is higher than that on the downstream side of the high temperature gas. Accordingly, the thermal expansion on the upstream side of high temperature gas is larger than that on the downstream side of the high temperature gas on which the heat resistant filler 55 is arranged. Thus,.the pressing force to the heat resistant filler 55 on the downstream side is smaller that that on the upstream side. Further, the bulging force to the upper and lower portion 43 b , 43 c of the housing body 43 on downstream side is smaller than that on the upstream side. The deformation of the upper and lower portions 43 b , 43 c of the housing body 43 can be effectively absorbed by arranging the heat resistant filler 53 on the downstream side. Thus, the deformation of the joint portion of flange 43 a of the housing body 43 and the upper and lower end portions 37 a of the side wall plate 37 and the deformation of the side wall plates 37 can be effectively prevented. Thus, the joint strength of the joint portion can be secured, so that the durability of the housing 3 can be improved.
[0051] FIG. 10 shows the fifth embodiment of the present invention. FIG. 10 corresponds to FIG. 2 described above. In FIG. 10 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . FIG. 11 is a view from the right side of FIG. 10 , in which a side wall plate has been removed. In this embodiment, a projection member 57 is provided on the central portion of the upper and lower portions 43 b , 43 c of the housing body in the flow direction of high temperature gas. The projection member 57 projects outward and extends over the whole width in the rightward and leftward direction in FIG. 10 . The projection member 57 is composed of separate member and secured to the upper and lower portion 43 b , 43 c of the housing body 43 by welding or brazing.
[0052] The inside of the projection member 57 defines a filler accommodating portion 59 for accommodating a part of the heat resistant filler 61 . A spring (elastic member) 63 intervenes between the heat resistant filler 61 and the bottom of the filler accommodating portion 59 . The spring 63 is composed of a waved plate having elasticity. The elastic force of the spring 36 is smaller than that of the heat resistant filler 61 .
[0053] The filler accommodating portion 59 and spring 63 constitute a heat deformation absorbing mechanism. The part 61 a of the heat resistant filler 61 corresponding to the side wall plate 37 may have the same thickness as the part of the heat resistant filler 61 accommodated in the filler accommodating portion 59 or may have larger thickness than that of the part of the heat resistant filler 61 accommodated in the filler accommodating portion 59 . Further, the spring 63 is not limited to a wave form and may take other forms.
[0054] In this embodiment, due to the thermal expansion of the heat exchange section, the heat resistant filler 61 is pressed. However, this pressing force is absorbed by the elastic deformation of the spring 63 , and thus the deformation of the upper and lower portion of the housing body 43 is suppressed. Thus, the deformation of the joint portion of the flange 43 a of the housing body 43 and the upper and lower end portions 37 a of the side wall plate 37 and the deformation of the side wall plates 37 can be effectively prevented. Thus, the joint strength of the joint portion can be secured, so that the durability of the housing 3 can be improved.
[0055] Further, since the heat resistant filler 61 is pressed to the heat exchange section 1 by the spring 63 , seal properties against the high temperature gas can be improved. Further, by appropriately changing the depth of the filler accommodating portion 59 and the elasticity of the spring 63 , material for the heat exchange section 1 and the housing 3 can be changed easily, thus improves flexibility in selection of materials.
[0056] FIG. 12 shows the sixth embodiment of the present invention. FIG. 12 corresponds to FIG. 1 described above. In FIG. 12 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . FIG. 13 is a plan view of FIG. 12 . In this embodiment, two protrusions 65 (first protrusion) (heat deformation absorbing mechanism) extending in the vertical direction of FIG. 12 and perpendicularly to the flow direction of the high temperature gas are formed on the central portion of the side wall plate 37 in rightward and leftward directions in FIG. 12 . The protrusion 65 is formed on the area of the side wall plate 37 corresponding to the heat resistant filler 45 in the flow direction of the high temperature gas, and extends from the upper end portion 37 a to lower end portion 37 a . As shown in FIG. 13 , the protrusion 65 projects outward from the heat exchange section 1 . The flange 43 a of the housing body 43 corresponding to the upper and lower end portion 37 a is formed with protrusion (second protrusion) 67 corresponding to protrusion 65 .
[0057] FIG. 14 is a partially enlarged view of the part designated with arrow B in FIG. 13 . As shown in FIG. 14 , the protrusion 67 formed in the flange 43 a of the housing body 43 projects into the recess formed in the upper and lower end portions 37 a of the side wall plate 37 .
[0058] The upper and lower portion 43 b , 43 c of the housing body is formed with the wave form portion 49 similar to that in the second embodiment shown in FIGS. 6 and 7 .
[0059] In the embodiment shown in FIGS. 12 to 14 , the protrusions 65 , 67 absorb the deformation of the side wall plate 37 due to difference in thermal expansion of the heat exchange section 1 caused by difference in temperature along the flow direction of high temperature gas. Thus, the deformation of the joint portion of flange 43 a of the housing body 43 and the upper and lower end portions 37 a of the side wall plate 37 and the deformation of the side wall plates 37 can be effectively prevented. Further, as in the second embodiment, the wave form portion 49 with its deformation absorbs the thermal expansion of the heat exchange section 1 in a vertical direction in FIG. 12 .
[0060] In addition, the side wall plate 37 is formed with protrusion 65 , so that the side wall plate 37 is formed with grooves on the inner face thereof opposite to the heat exchange section 1 . However, since the area C of the side wall plate 37 opposite to the core 5 in FIG. 12 is joined airtightly to the core 5 by brazing, and the area D of the side wall plate 37 opposite to the heat resistant filler 45 in FIG. 12 is filled with the heat resistant filler 45 in the groove, gas leaks from the groove can be prevented.
[0061] FIG. 15 shows the seventh embodiment of the present invention. FIG. 15 corresponds to FIG. 2 described above and is a view from the high temperature inlet side. In FIG. 15 , redundant explanation is omitted by using like numbers for like members in FIGS. 1 to 4 . FIG. 16 is a cross sectional view taken along the line 16 - 16 in FIG. 15 . In this embodiment, the heat resistant filler 45 is prevented from being subjected to high temperature gas, and further, the heat deformation absorbing mechanism described in the above embodiment is provided on the heat exchanger, thus the deformation of the housing 3 is securely suppressed. In this embodiment, a heat deformation absorbing mechanism 47 which is the same as that of the first embodiment is adopted.
[0062] The three peripheral portions of the housing body 43 on the high temperature gas inlet side are folded inside to form folded portions 69 , 71 , 73 . The distal end of the folded portions 69 , 71 , 73 abut against the outer periphery of the heat exchange section 1 . The rest of the structure is the same as that of the first embodiment. FIG. 17 shows a perspective view of the housing body in which the folded portions 69 , 71 , 73 are not formed yet. FIG. 18 shows a perspective view of the housing body in which the folded portions 69 , 71 , 73 have been formed.
[0063] With the seventh embodiment, the high temperature gas flowed into the heat exchanger from left side in FIG. 16 is restricted from directly flowing into the heat resistant filler 45 by the folded portions 69 , 71 , 73 . The heat resistant filler 45 , composed of inorganic fiber such as glass wool and binder, is not directly subjected to the high temperature gas (300° C. to 800° C.) and receives heat through heat exchange section 1 . Thus, the heat resistant filler 45 is subjected to heat of a lower temperature by several tens of degrees centigrade to several hundreds of degrees centigrade lower than that of the high temperature gas, so that deterioration and change in quality of the heat resistant filler 45 can be effectively prevented. Especially, when a generation device for the high temperature gas is a burner, fire is effectively restricted from entering into the heat resistant filler 45 .
[0064] As the result, the housing 43 can be securely prevented from deforming with the heat deformation absorbing mechanism 47 .
[0065] Japanese Patent Application No. 2002-28445 is expressly incorporated herein by reference in its entirety.