Heating apparatus

Abstract

To provide a technique which can improve heat exchange efficiency with use of a compact structure.SOLUTION: A heating apparatus may comprise: a spiral sheath heater; an upper surface side member facing an upper surface of the sheath heater; a lower surface side member facing a lower surface of the sheath heater; an upper surface side passage, provided between the upper surface of the sheath heater and the upper surface side member, which flows fluid along the upper surface of the sheath heater in a radial direction of the sheath heater; and a lower surface side passage, provided between the lower surface of the sheath heater and the lower surface side member, which flows the fluid along the lower surface of the sheath heater in the radial direction of the sheath heater.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a heating device. [Background technology]

[0002] Patent Document 1 discloses a heating device. The heating device of Patent Document 1 includes a spiral heater, a lower surface member facing the lower surface of the heater, a lower surface flow path provided between the lower surface of the heater and the lower surface member, which flows a fluid in the radial direction of the heater along the lower surface of the heater, and an inlet port that introduces a fluid toward the center of the spiral heater. In the heating device of Patent Document 1, the fluid heated by the heater flows above the heater. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 60-7184 Summary of the Invention [Problem to be solved by the invention]

[0004] The heating device in Patent Document 1 has a configuration in which the fluid heated by the heater flows above the heater, so the area above the heater needs to be widened, which results in a problem that the heating device configuration becomes large. Also, the heating device in Patent Document 1 has a configuration in which the fluid flows above the heater, so there is a problem that the heat of the heater cannot be efficiently transferred to the fluid.

[0005] The present specification provides a technique that can improve heat exchange efficiency with a compact configuration. [Means for solving the problem]

[0006] In a first aspect of the present technology, a heating device may include a spiral-shaped sheathed heater, an upper surface side member facing an upper surface of the sheathed heater, a lower surface side member facing a lower surface of the sheathed heater, an upper surface side flow path provided between the upper surface of the sheathed heater and the upper surface side member, the upper surface side flow path flowing a fluid in a radial direction of the sheathed heater along the upper surface of the sheathed heater, and a lower surface side flow path provided between the lower surface of the sheathed heater and the lower surface side member, the lower surface side flow path flowing a fluid in the radial direction of the sheathed heater along the lower surface of the sheathed heater.

[0007] According to this configuration, the lower side flow passage causes the fluid to flow in the radial direction of the sheathed heater along the lower surface of the sheathed heater, and the upper side flow passage causes the fluid to flow in the radial direction of the sheathed heater along the upper surface of the sheathed heater, so that the heat of the sheathed heater can be efficiently transferred to the fluid, and the heat exchange efficiency can be improved. In addition, the upper side flow passage causes the fluid to flow in the radial direction of the sheathed heater along the upper surface of the sheathed heater, so that the area above the sheathed heater can be narrowed, and the configuration of the heating device can be made compact. Therefore, the heat exchange efficiency can be improved with a compact configuration.

[0008] In a second aspect, the heating device in the first aspect may further include an inlet for introducing a fluid toward a center of the spiral sheathed heater, and an outlet for discharging the fluid in a tangential direction of the outermost periphery of the spiral sheathed heater. With this configuration, the fluid can be sufficiently heated by the sheathed heater before being discharged.

[0009] In a third aspect, in the second aspect, the outlet may be provided at a position opposite to an end of the outermost periphery of the sheath heater. With this configuration, the fluid can be smoothly flowed to the outlet.

[0010] In a fourth aspect, in the first or third aspect, the inlet may be provided above the upper surface of the sheathed heater. With this configuration, the fluid can be sufficiently introduced into both the upper surface side flow path and the lower surface side flow path.

[0011] In a fifth aspect, in the first aspect, the heating device may further include an outer flow passage provided outside the outermost periphery of the spiral-shaped sheathed heater, the outer flow passage causing a fluid to flow in the circumferential direction of the sheathed heater along the outermost periphery of the sheathed heater, and a connecting flow passage provided between the outermost periphery of the sheathed heater and the outer flow passage, causing the fluid to flow into the outer flow passage after flowing through the upper surface side flow passage and the lower surface side flow passage. The vertical width of the connecting flow passage may be narrower than the vertical width of the sheathed heater and narrower than the vertical width of the outer flow passage.

[0012] According to this configuration, the flow rate of the fluid flowing through the connecting flow path can be increased, and therefore the flow rate of the fluid near the outermost portion of the sheathed heater can be increased. This allows the temperature of the outermost portion of the sheathed heater to be lowered. As a result, the temperature of the outermost portion of the sheathed heater can be made closer to the temperature of the innermost portion, and the temperature of the entire sheathed heater can be made closer to uniform. As a result, the temperature of the fluid can be made closer to uniform, and the heat exchange efficiency can be improved.

[0013] In a sixth aspect, in the fifth aspect, the heating device may further include an inlet for introducing a fluid toward a center of the spiral-shaped sheathed heater, and an outlet for discharging the fluid from the outer flow path.

[0014] With this configuration, the fluid heated by the sheathed heater can be collected in an outer flow path located outside the outermost circumference of the sheathed heater, and the temperature of the fluid heated by the sheathed heater can be made nearly uniform in the circumferential direction of the sheathed heater.

[0015] In a seventh aspect, in the fifth aspect, the heating device may further include an inlet for introducing a fluid into the outer flow path and an outlet for discharging the fluid from the center of the spiral-shaped sheath heater.

[0016] This configuration makes it possible to increase the flow rate of the fluid near the center of the sheathed heater, thereby improving the heat flux near the center of the sheathed heater and improving the heat exchange efficiency.

[0017] In an eighth aspect, in any one of the first to seventh aspects, the width of the upper surface side flow path in the vertical direction may be greater than the width of the lower surface side flow path in the vertical direction. With this configuration, it is possible to smoothly introduce a fluid into the upper surface side flow path.

[0018] In a ninth aspect, in any one of the first to eighth aspects, the width of the upper surface side flow passage in the vertical direction may be narrower than the width of the sheathed heater in the vertical direction. With this configuration, the flow rate of the fluid flowing through the upper surface side flow passage can be increased. This can improve the heat flux and the heat exchange efficiency. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a cross-sectional view of the heating device according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the heating device according to the first embodiment (a cross-sectional view taken along line II-II in FIG. 1). [Diagram 3] An enlarged view of part III of FIG. [Figure 4] FIG. 6 is a cross-sectional view of a heating device according to a second embodiment. [Diagram 5] 5 is a cross-sectional view of a heating device according to a second embodiment (a cross-sectional view taken along line VV in FIG. 4). [Figure 6] An enlarged view of part VI of Figure 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (First Example) A heating device 2 of a first embodiment will be described with reference to the drawings. As shown in Figs. 1 to 3, the heating device 2 includes a spiral sheathed heater 10 and a housing 4 that houses the sheathed heater 10. The heating device 2 also includes an inlet pipe 6 that introduces a fluid into the housing 4, and an outlet pipe 7 that discharges the fluid to the outside of the housing 4. The fluid introduced into the housing 4 is, for example, water or a coolant liquid. The fluid introduced into the housing 4 functions as a heat medium for the heating device 2.

[0021] (Configuration of sheath heater 10) The sheathed heater 10 is an electric heater that generates heat when electricity is applied. The sheathed heater 10 includes, for example, a heating element 90, a tubular housing 94 that houses the heating element 90, and a powdered insulating material 96 that fills the gap between the heating element 90 and the housing 94. The heating element 90 is formed of, for example, a spiral nichrome wire. The principle by which the sheathed heater 10 generates heat is already known, so a detailed description will be omitted.

[0022] The spiral-shaped sheathed heater 10 has an inner end 12 and an outer end 13 in the spiral direction. The inner end 12 and the outer end 13 each have an electrical terminal (not shown). Electric power is supplied to the sheathed heater 10 through the electrical terminal of the inner end 12 and the electrical terminal of the outer end 13. Each of the multiple winding portions of the spiral-shaped sheathed heater 10 makes one revolution in the spiral direction of the sheathed heater 10. For example, the innermost portion 14 and the outermost portion 15 of the sheathed heater 10 each make one revolution in the spiral direction of the sheathed heater 10.

[0023] (Configuration of Chassis 4) The housing 4 has a storage section 40 that stores the spirally wound sheathed heater 10. The housing 4 has an upper surface side member 42 that faces the upper surface 10a of the sheathed heater 10, a lower surface side member 44 that faces the lower surface 10b of the sheathed heater 10, and a side surface side member 46 that faces the side surface 10c of the outermost peripheral portion 15 of the sheathed heater 10. The storage section 40 is formed in a portion surrounded by the upper surface side member 42, the lower surface side member 44, and the side surface side member 46.

[0024] The upper surface side member 42 of the housing 4 extends laterally along the upper surface 10a of the sheathed heater 10. The upper surface side member 42 extends in the radial direction of the sheathed heater 10. An upper surface side flow path 22 is provided between the upper surface 10a of the sheathed heater 10 and the upper surface side member 42.

[0025] The upper surface side flow path 22 extends laterally along the upper surface 10a of the sheathed heater 10. The upper surface side flow path 22 extends in the radial direction of the sheathed heater 10. The upper surface side flow path 22 is a flow path that flows a fluid laterally along the upper surface 10a of the sheathed heater 10. The upper surface side flow path 22 is a flow path that flows a fluid in the radial direction of the sheathed heater 10. The vertical width W22 of the upper surface side flow path 22 is, for example, narrower than three times (=3×W10) the vertical width W10 of the sheathed heater 10. The vertical width W22 of the upper surface side flow path 22 may be, for example, narrower than twice (=2×W10) the vertical width W10 of the sheathed heater 10. The vertical width W22 of the upper surface side flow path 22 may be, for example, narrower than the vertical width W10 of the sheathed heater 10.

[0026] The lower surface side member 44 of the housing 4 extends laterally along the lower surface 10b of the sheathed heater 10. The lower surface side member 44 extends in the radial direction of the sheathed heater 10. A lower surface side flow path 24 is provided between the lower surface 10b of the sheathed heater 10 and the lower surface side member 44.

[0027] The lower side flow path 24 extends laterally along the lower surface 10b of the sheathed heater 10. The lower side flow path 24 extends in the radial direction of the sheathed heater 10. The lower side flow path 24 is a flow path that flows a fluid laterally along the lower surface 10b of the sheathed heater 10. The lower side flow path 24 is a flow path that flows a fluid in the radial direction of the sheathed heater 10. The vertical width W24 of the lower side flow path 24 is, for example, narrower than three times (=3×W10) the vertical width W10 of the sheathed heater 10. The vertical width W24 of the lower side flow path 24 may be, for example, narrower than twice (=2×W10) the vertical width W10 of the sheathed heater 10. The vertical width W24 of the lower side flow path 24 may be, for example, narrower than the vertical width W10 of the sheathed heater 10.

[0028] The inner peripheral surface of the side member 46 of the housing 4 extends in the circumferential direction of the outermost peripheral portion 15 along the side 10c of the outermost peripheral portion 15 of the spiral sheathed heater 10. The upper surface side flow path 22 and the lower surface side flow path 24 merge in the gap 26 between the side 10c of the outermost peripheral portion 15 of the sheathed heater 10 and the side member 46. The width W26 of the gap 26 between the side 10c of the outermost peripheral portion 15 of the sheathed heater 10 and the side member 46 is, for example, narrower than twice the width W10 of the sheathed heater 10 in the vertical direction (=2×W10). The width W26 of this gap 26 may be narrower than the width W10 of the sheathed heater 10 in the vertical direction. The width W26 of this gap 26 may also be narrower than the width W22 of the upper surface side flow path 22 in the vertical direction, for example. The width W26 of the gap 26 may be narrower than the width W24 of the lower surface side flow passage 24 in the up-down direction, for example.

[0029] The housing 4 further includes an outlet 27 and a first exhaust flow path 28 for discharging the fluid from the storage section 40. The outlet 27 and the first exhaust flow path 28 laterally discharge the fluid from the storage section 40. The outlet 27 is provided in the side member 46 of the housing 4. The outlet 27 is provided at a position facing the end (i.e., the outer end 13) of the outermost periphery 15 of the sheathed heater 10. The outlet 27 opens toward the outer end 13 of the sheathed heater 10. The outlet 27 discharges the fluid in a tangent direction D1 of the outermost periphery 15 of the sheathed heater 10 at the outer end 13 of the sheathed heater 10. The tangent (D1) of the outermost periphery 15 of the sheathed heater 10 at the outer end 13 of the sheathed heater 10 passes through the outlet 27.

[0030] The first exhaust flow path 28 extends in a tangential direction D1 of the outermost periphery 15 of the sheathed heater 10 at the outer end 13 of the sheathed heater 10. The first exhaust flow path 28 extends in a horizontal direction. In a modified example, the first exhaust flow path 28 may extend in a direction other than the tangential direction D1. The first exhaust flow path 28 communicates with the storage section 40 of the housing 4 via the exhaust port 27. The first exhaust flow path 28 extends from the inside of the housing 4 (the storage section 40) to the outside of the housing 4.

[0031] (Configuration of inlet pipe 6 and outlet pipe 7) The introduction pipe 6 is connected to the upper surface member 42 of the housing 4. The downstream end of the introduction pipe 6 is fixed to the upper surface member 42 of the housing 4. The introduction pipe 6 extends vertically from the upper part of the housing 4 toward the upper side. The introduction pipe 6 may be manufactured integrally with the housing 4. The introduction pipe 6 includes an introduction flow path 60 and an introduction port 62 that introduce a fluid into the interior of the housing 4 (the storage section 40).

[0032] The introduction flow path 60 communicates with the inside of the housing 4 (the storage section 40) via an introduction port 62. The introduction flow path 60 extends in the vertical direction. The horizontal width W60 of the introduction flow path 60 is, for example, wider than the vertical width W22 of the above-mentioned upper surface side flow path 22.

[0033] The inlet 62 is provided at the downstream end of the introduction flow passage 60. The inlet 62 is provided at a position above the upper surface 10a of the sheathed heater 10. The inlet 62 opens above the upper surface 10a of the sheathed heater 10. The inlet 62 is provided at a position facing the center 16 of the sheathed heater 10. The center 16 of the sheathed heater 10 is a part inside the innermost periphery 14 of the spiral sheathed heater 10. The inlet 62 opens toward the center 16 of the sheathed heater 10. The inlet 62 expands in diameter toward the storage section 40 of the housing 4. The diameter of the inlet 62 expands toward the lower side. The inner circumferential surface of the inlet 62 is inclined with respect to the longitudinal direction of the introduction flow passage 60. The introduction flow passage 60 and the inlet 62 introduce a fluid toward the center 16 of the sheathed heater 10. In a modified example, the introduction port 62 does not have to be expanded in diameter.

[0034] The discharge pipe 7 is connected to the side surface member 46 of the housing 4. The upstream end of the discharge pipe 7 is fixed to the side surface member 46 of the housing 4. The discharge pipe 7 extends laterally from the side surface member 46 of the housing 4. The discharge pipe 7 may be manufactured integrally with the housing 4. The discharge pipe 7 includes a second discharge flow path 72 that discharges the fluid. The second discharge flow path 72 communicates with the first discharge flow path 28 provided in the side surface member 46 of the housing 4.

[0035] (Operation of heating device 2) In the heating device 2 described above, a fluid is introduced into the storage section 40 of the housing 4 through an introduction pipe 6 connected to the housing 4. The fluid is introduced toward the center 16 of the sheathed heater 10. The fluid introduced into the center 16 of the sheathed heater 10 flows from the center 16 of the sheathed heater 10 into the upper surface side flow passage 22 and the lower surface side flow passage 24. This fluid flows radially along the upper surface 10a and lower surface 10b of the sheathed heater 10 to the outside in the radial direction of the sheathed heater 10. The fluid flowing through the upper surface side flow passage 22 and the lower surface side flow passage 24 is heated by the sheathed heater 10 as it flows in the radial direction of the sheathed heater 10.

[0036] The fluid heated by the sheathed heater 10 flows in the circumferential direction of the sheathed heater 10 along the outermost peripheral portion 15 of the sheathed heater 10, and is discharged from an outlet 27 facing the end (outer end 13) of the outermost peripheral portion 15 of the sheathed heater 10 to a first discharge flow path 28. The fluid discharged from the outlet 27 is discharged to the first discharge flow path 28 along a tangential direction D1 of the outermost peripheral portion 15 of the sheathed heater 10. The fluid discharged to the first discharge flow path 28 is discharged to the outside of the housing 4 by an exhaust pipe 7 connected to the housing 4.

[0037] (effect) The heating device 2 of the first embodiment has been described above. As described above, the heating device 2 includes an upper surface side flow passage 22 provided between the upper surface 10a of the sheathed heater 10 and the upper surface side member 42, which allows a fluid to flow in the radial direction of the sheathed heater 10 along the upper surface 10a of the sheathed heater 10. The heating device 2 also includes a lower surface side flow passage 24 provided between the lower surface 10b of the sheathed heater 10 and the lower surface side member 44, which allows a fluid to flow in the radial direction of the sheathed heater 10 along the lower surface 10b of the sheathed heater 10.

[0038] According to this configuration, by flowing a fluid along the lower surface 10b of the sheathed heater 10 through the lower surface side flow passage 24 and flowing a fluid along the upper surface 10a of the sheathed heater 10 through the upper surface side flow passage 22, the heat of the sheathed heater 10 can be transferred from the lower surface 10b and the upper surface 10a of the sheathed heater 10 to the fluid, improving the heat exchange efficiency. In addition, by flowing a fluid along the upper surface 10a of the sheathed heater 10 through the upper surface side flow passage 22, the area above the sheathed heater 10 can be narrowed, so the configuration of the heating device 2 can be made compact. Therefore, the heat exchange efficiency can be improved with a compact configuration.

[0039] The heating device 2 also includes an inlet 62 for introducing a fluid toward the center 16 of the spiral-shaped sheathed heater 10, and an outlet 27 for discharging the fluid in the tangential direction D1 of the outermost periphery 15 of the spiral-shaped sheathed heater 10. With this configuration, the fluid can be sufficiently heated by the sheathed heater 10 before being discharged.

[0040] The exhaust port 27 is provided at a position facing the end (outer end 13) of the outermost periphery 15 of the sheathed heater 10. With this configuration, the fluid can flow to the exhaust port 27 smoothly.

[0041] The inlet 62 is provided above the upper surface 10a of the sheathed heater 10. According to this configuration, the fluid can be sufficiently introduced into both the upper surface side flow path 22 and the lower surface side flow path 24.

[0042] The vertical width W22 of the top surface side flow path 22 may be greater than the vertical width W24 of the bottom surface side flow path 24. With this configuration, the fluid can be introduced into the top surface side flow path 22 smoothly.

[0043] Furthermore, the vertical width W22 of the top surface side flow passage 22 may be narrower than the vertical width W10 of the sheathed heater 10. This configuration can increase the flow rate of the fluid flowing through the top surface side flow passage 22. This can improve the heat flux and the heat exchange efficiency.

[0044] Although the first embodiment has been described above, the aspect of the heating device 2 is not limited to the above embodiment. In the following description, detailed description of the same configuration as in the above description may be omitted.

[0045] (Second Example) The heating device 2 of the second embodiment will be described below. As shown in Fig. 4 to Fig. 6, the heating device 2 of the second embodiment includes an outer flow passage 50 and a connecting flow passage 52.

[0046] The outer flow path 50 and the connection flow path 52 are provided in the side member 46 of the housing 4. The outer flow path 50 and the connection flow path 52 are provided around the housing portion 40 of the housing 4 and surround the housing portion 40. The outer flow path 50 and the connection flow path 52 are provided outside the housing portion 40 in the radial direction of the sheathed heater 10. The outer flow path 50 and the connection flow path 52 are provided around the outermost peripheral portion 15 of the sheathed heater 10 and surround the outermost peripheral portion 15 of the sheathed heater 10. The outer flow path 50 and the connection flow path 52 are provided outside the outermost peripheral portion 15 of the sheathed heater 10 in the radial direction of the sheathed heater 10. The outer flow path 50 and the connection flow path 52 extend along the outermost peripheral portion 15 of the sheathed heater 10 in the circumferential direction of the outermost peripheral portion 15.

[0047] The outer flow path 50 communicates with the storage section 40 of the housing 4 via the connection flow path 52. The outer flow path 50 communicates with the upper surface side flow path 22 and the lower surface side flow path 24 via the connection flow path 52. The outer flow path 50 also communicates with the first discharge flow path 28 via the discharge port 27. The outer flow path 50 is a flow path that flows a fluid along the outermost peripheral portion 15 of the sheathed heater 10 in the circumferential direction of the outermost peripheral portion 15. The vertical width W50 of the outer flow path 50 is wider than the vertical width W10 of the sheathed heater 10. The vertical width W50 of the outer flow path 50 is wider than the sum (=W22+W24) of the vertical width W22 of the upper surface side flow path 22 and the vertical width W24 of the lower surface side flow path 24.

[0048] The connection flow path 52 is provided between the outermost peripheral portion 15 of the sheath heater 10 and the outer flow path 50. The connection flow path 52 is provided between the storage section 40 of the housing 4 and the outer flow path 50. The connection flow path 52 connects the storage section 40 and the outer flow path 50. The connection flow path 52 communicates with the storage section 40 and the outer flow path 50. The connection flow path 52 communicates with the upper surface side flow path 22 and the lower surface side flow path 24. The connection flow path 52 is a flow path that discharges a fluid from the storage section 40 of the housing 4 to the outer flow path 50. The connection flow path 52 is a flow path that flows the fluid after flowing through the upper surface side flow path 22 and the lower surface side flow path 24 to the outer flow path 50. The vertical width W52 of the connection flow path 52 is narrower than the vertical width W10 of the sheath heater 10 and is narrower than the vertical width W50 of the outer flow path 50. The vertical width W52 of the connection flow passage 52 is narrower than the vertical width W22 of the top surface side flow passage 22 and is narrower than the vertical width W24 of the bottom surface side flow passage 24.

[0049] In the heating device 2 of the second embodiment, the fluid heated by the sheathed heater 10 is discharged from the storage section 40 of the housing 4 through the connecting flow path 52 to the outer flow path 50. The fluid discharged to the outer flow path 50 flows through the outer flow path 50 along the outermost peripheral portion 15 of the sheathed heater 10, and is discharged from the discharge port 27 to the first discharge flow path 28. The fluid discharged to the first discharge flow path 28 is discharged to the outside of the housing 4 by the discharge pipe 7 connected to the housing 4.

[0050] (effect) The heating device 2 of the second embodiment has been described above. As described above, the heating device 2 includes the outer flow path 50 and the connecting flow path 52. The vertical width W52 of the connecting flow path 52 is narrower than the vertical width W10 of the sheath heater 10 and is also narrower than the vertical width W50 of the outer flow path 50.

[0051] According to this configuration, the flow rate of the fluid flowing through the connection flow path 52 can be increased, and therefore the flow rate of the fluid near the outermost portion 15 of the sheathed heater 10 can be increased. This allows the temperature of the outermost portion 15 of the sheathed heater 10 to be lowered. As a result, the temperature of the outermost portion 15 of the sheathed heater 10 can be made closer to the temperature of the innermost portion 14, and the temperature of the entire sheathed heater 10 can be made closer to uniform. In addition, by collecting the fluid heated by the sheathed heater 10 in the outer flow path 50 provided outside the outermost portion 15 of the sheathed heater 10, the temperature of the fluid heated by the sheathed heater 10 can be made closer to uniform in the circumferential direction of the sheathed heater 10. As a result, the temperature of the fluid can be made closer to uniform, and the heat exchange efficiency can be improved.

[0052] (Modification) In each of the above embodiments, the fluid is introduced toward the center 16 of the spirally wound sheathed heater 10, but the present invention is not limited to this configuration. In a modified example, the fluid may be introduced toward a portion other than the center 16 of the sheathed heater 10. For example, the fluid may be introduced toward the end (outer end 13) of the outermost periphery 15 of the sheathed heater 10. In this case, the exhaust pipe 7 shown in FIG. 1 serves as the introduction pipe, and the introduction pipe 6 shown in FIG. 2 serves as the exhaust pipe.

[0053] In addition, in a modified example, a configuration may be adopted in which a fluid is introduced into the outer flow path 50. In this case, the exhaust pipe 7 shown in Fig. 4 serves as the inlet pipe, and the inlet pipe 6 shown in Fig. 5 serves as the outlet pipe. The heating device 2 in the modified example includes an inlet (exhaust port 27 shown in Fig. 4) for introducing a fluid into the outer flow path 50, and an outlet (inlet port 62 shown in Fig. 5) for discharging the fluid from the center portion 16 of the sheathed heater 10.

[0054] In this modification, the fluid introduced into the outer flow path 50 from the inlet (27) flows into the storage section 40 of the housing 4 through the connecting flow path 52. The fluid that flows into the storage section 40 flows into the upper surface side flow path 22 and the lower surface side flow path 24, and flows radially inward in the radial direction of the sheathed heater 10 along the upper surface 10a and the lower surface 10b of the sheathed heater 10. The fluid flowing through the upper surface side flow path 22 and the lower surface side flow path 24 is heated by the sheathed heater 10 as it flows in the radial direction of the sheathed heater 10. The fluid heated by the sheathed heater 10 is discharged from an outlet (62) facing the center 16 of the sheathed heater 10 to a discharge flow path (the inlet flow path 60 shown in FIG. 5).

[0055] This configuration makes it possible to increase the flow rate of the fluid near the center 16 of the sheathed heater 10. This makes it possible to improve the heat flux near the center 16 of the sheathed heater 10, thereby improving the heat exchange efficiency.

[0056] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0057] 2: heating device, 4: housing, 6: inlet pipe, 7: outlet pipe, 10: sheath heater, 10a: upper surface, 10b: lower surface, 10c: side surface, 12: inner end, 13: outer end, 14: innermost periphery, 15: outermost periphery, 16: center, 22: upper surface side flow path, 24: lower surface side flow path, 26: gap, 27: outlet, 28: first outlet flow path, 40: storage section, 42: upper surface side member, 44: lower surface side member, 46: side surface side member, 50: outer flow path, 52: connection flow path, 60: inlet flow path, 62: inlet, 72: second outlet flow path, 90: heating element, 94: housing, 96: insulating material, 142: intermediate member

Claims

1. A spiral sheath heater, An upper surface side member facing an upper surface of the sheath heater; A lower surface side member facing the lower surface of the sheath heater; An upper surface side flow path provided between an upper surface of the sheath heater and the upper surface side member, the upper surface side flow path allowing a fluid to flow in a radial direction of the sheath heater along the upper surface of the sheath heater; A heating device comprising: a bottom-side flow path provided between a bottom surface of the sheathed heater and the bottom-side member, the bottom-side flow path allowing a fluid to flow radially along the bottom surface of the sheathed heater.

2. The heating device according to claim 1 , an inlet for introducing a fluid toward a center of the spiral sheath heater; The heating device further comprises an outlet for discharging a fluid in a tangential direction of the outermost periphery of the spiral sheath heater.

3. The heating device according to claim 2, A heating device, wherein the exhaust port is provided at a position opposite to an end of the outermost periphery of the sheath heater.

4. The heating device according to claim 2 or 3, A heating device, wherein the inlet is provided above an upper surface of the sheath heater.

5. The heating device according to claim 1 , An outer flow path is provided outside the outermost peripheral portion of the spiral-shaped sheathed heater, and the outer flow path causes a fluid to flow in a circumferential direction of the sheathed heater along the outermost peripheral portion of the sheathed heater; A connecting flow path is provided between the outermost peripheral portion of the sheath heater and the outer flow path, and the connecting flow path causes the fluid after flowing through the upper surface side flow path and the lower surface side flow path to flow into the outer flow path. A heating device, wherein the vertical width of the connection flow path is narrower than the vertical width of the sheathed heater and is also narrower than the vertical width of the outer flow path.

6. The heating device according to claim 5, an inlet for introducing a fluid toward a center of the spiral sheath heater; and an outlet for discharging fluid from the outer flow passage.

7. The heating device according to claim 5, an inlet for introducing a fluid into the outer flow passage; The heating device further comprises an outlet for discharging fluid from a center of the spiral sheath heater.

8. The heating device according to claim 1 , A heating device, wherein the upper surface side flow path has a width in the vertical direction that is greater than the width in the vertical direction of the lower surface side flow path.

9. The heating device according to claim 1 , A heating device, wherein a vertical width of the upper surface side flow path is narrower than a vertical width of the sheath heater.

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