WO2017002563A1 - Fluid heating device - Google Patents

Abstract

A fluid heating device that heats fluid comprises a heater unit having a heater and a heating part formed so as to surround the heater, wherein the heating part has an inside heat exchange surface that exchanges heat with fluid and is formed on the inside surface of a through-hole that passes through the inside of the heater, and an outside heat exchange surface that exchanges heat with fluid and is formed on an outside wall section on the outside of the heater.

Description

Fluid heating device

The present invention relates to a fluid heating apparatus for heating a fluid.

JP2014-053288A discloses a fluid heating apparatus that heats a fluid supplied from a supply passage into a tank by a heater and discharges the fluid from a discharge passage. In this fluid heating apparatus, the fluid flowing through the tank is heated by a spiral heater provided in the tank.

However, in the fluid heating device of JP2014-053288A, the heat generating part of the heater is accommodated in a tank through which the fluid flows, and the fluid directly contacts the surface of the heat generating part to exchange heat. Therefore, the heat transfer area for heat exchange with the fluid depends on the size of the heater.

The object of the present invention is to increase the heat transfer area for heat exchange with the fluid.

According to an aspect of the present invention, there is provided a fluid heating apparatus that heats a fluid, and includes a heater unit that includes a heater and a heating unit that is formed to cover the periphery of the heater, and the heating unit includes the heater. An inner heat exchange surface that is formed on the inner surface of the through-hole penetrating the inside of the heater and exchanges heat with the fluid, and an outer heat exchange surface that is formed on the outer outer wall portion of the heater and exchanges heat with the fluid.

In this aspect, the heater unit has a heating portion formed so as to cover the heater. The heating unit has an inner heat exchange surface formed on the inner surface of the through hole penetrating the inside of the heater, and an outer heat exchange surface formed on the outer wall portion outside the heater. In the heater unit, since the surface area of the heating unit is a heat transfer area for exchanging heat with the fluid, the total surface area of the inner heat exchange surface and the outer heat exchange surface is the heat transfer area. Therefore, compared with the case where a heater and a fluid are made to contact directly, the heat transfer area for heat-exchange with a fluid can be enlarged.

FIG. 1 is an exploded perspective view of a fluid heating apparatus according to an embodiment of the present invention. FIG. 2 is a side view of the heater unit and the tank of the fluid heating device, and is a view showing the tank in cross section. FIG. 3 is a front view of the heater unit and the tank of the fluid heating device, and is a view showing the tank in cross section. FIG. 4 is a front view of a heater unit and a tank of a fluid heating apparatus according to a modification of the embodiment of the present invention, and is a view showing the tank in cross section. FIG. 5 is a diagram for explaining a temperature change of the fluid heated by the fluid heating device.

Hereinafter, a fluid heating device 100 according to an embodiment of the present invention will be described with reference to the drawings.

The fluid heating device 100 is applied to a vehicle air conditioner (not shown) mounted on a vehicle such as an EV (Electric Vehicle) or HEV (Hybrid Electric Vehicle). The fluid heating device 100 heats hot water as a fluid in order for the vehicle air conditioner to perform a heating operation.

First, the overall configuration of the fluid heating apparatus 100 will be described with reference to FIGS.

As shown in FIG. 1, the fluid heating device 100 includes a tank 10 through which water flows, a heater unit 20 accommodated in the tank 10, a bus bar module 30 for connecting various electrical components, and a heater unit 20. The control board 40 as a control part for controlling operation | movement and the cover 50 which covers the bus-bar module 30 and the control board 40 are provided.

The tank 10 is formed in a substantially rectangular parallelepiped shape. The tank 10 has a rectangular bottom surface 13, a wall surface 14 erected from the bottom surface 13, and an opening 15 that opens at an end of the wall surface 14 so as to face the bottom surface 13. The tank 10 has a supply port 11 through which hot water is supplied and a discharge port 12 through which hot water is discharged. The supply port 11 and the discharge port 12 open side by side on the same wall surface 14 of the tank 10. The fluid heating device 100 is disposed in the vehicle such that the discharge port 12 is positioned above the supply port 11 when in use.

As shown in FIGS. 2 and 3, the heater unit 20 includes a heater 21, a heating part 22 formed so as to cover the heater 21, and a connecting part 29 that connects the top surface 16 and the heating part 22. , And a heat radiating fin 29 a as a pair of heat radiating portions formed so as to protrude from the connecting portion 29. In the heater unit 20, a metal is die-cast around the heater 21 to form the heating unit 22. The heater unit 20 is connected to the top surface 16 of the top plate portion 23 that closes the opening 15 for inserting the heater unit 20 via the connection portion 29, and is formed integrally with the top plate portion 23.

The heater 21 has a pair of terminals 21a and 21b to which electric power is supplied via a bus bar module 30 from a power supply device (not shown) mounted on the vehicle. The heater 21 has a spiral heat generating portion 21c protruding into the tank 10 between the pair of terminals 21a and 21b. The heater 21 may have a heat generating part that is not spiral, but is formed so as to reciprocate within the heating part 22, for example.

The heater 21 is a sheathed heater or a PTC (Positive Temperature Coefficient) heater that generates heat when energized. The heater 21 is preferably a sheathed heater in terms of cost. The heater 21 generates heat in response to a command from the control board 40 and heats the hot water flowing through the tank 10.

The heating part 22 is formed in a small diameter compared with the inner periphery of the heat generating part 21c and passes through the inside along the central axis of the heat generating part 21c, and compared with the outer periphery of the heat generating part 21c outside the heat generating part 21c. And an outer wall portion 26 that has a large diameter and faces the inner wall 17 of the tank 10. An inner heat exchange surface 25c for exchanging heat with the fluid is formed on the inner surface of the through hole 25, and an outer heat exchange surface 26c for exchanging heat with the fluid is formed on the outer wall portion 26. The heating unit 22 is formed of a metal having a lower melting point than that of the heater 21. Here, the heater 21 is formed of stainless steel, and the heating unit 22 is formed of an aluminum alloy.

The through hole 25 is formed inside the heat generating portion 21c wound in a spiral shape. The supply port 11 of the tank 10 opens on an extension line of the through hole 25. The through-hole 25 forms an inner peripheral flow path 27 (see FIG. 3) through which hot water supplied from the supply port 11 flows. Not only this but the discharge port 12 of the tank 10 may open on the extension line of the through-hole 25.

As shown in FIG. 3, the through-hole 25 has a plurality of inner peripheral fins 25a that protrude to the inner periphery along the flow direction of the hot water. The inner peripheral fin 25a increases the heat transfer area in the inner peripheral flow path 27 as compared with the case where the inner peripheral fin 25a is not provided. The plurality of inner peripheral fins 25 a are formed radially toward the inner periphery at equal angular intervals over the entire periphery of the through hole 25.

The outer wall portion 26 forms an outer peripheral flow path 28 through which hot water flows continuously with the inner peripheral flow path 27 between the inner wall 17 of the tank 10. The outer peripheral channel 28 guides the hot water flowing from the inner peripheral channel 27 to the discharge port 12. The outer wall portion 26 has a larger heat transfer area than the through hole 25. Further, the outer peripheral channel 28 has a larger channel area than the inner peripheral channel 27.

The outer wall portion 26 includes an outer wall main body 26a formed along the outer peripheral shape of the heater 21 and a plurality of outer peripheral fins 26b protruding from the outer wall main body 26a to the outer periphery along the flow direction of hot water.

The outer wall main body 26a is formed so as to cover the outer side of the heat generating portion 21c wound in a spiral shape. Since the outer wall main body 26a is provided, the heater 21 and the hot water are not in direct contact with each other.

The outer peripheral fin 26b increases the heat transfer area in the outer peripheral flow path 28 as compared with the case where the outer peripheral fin 26b is not provided. The outer peripheral fins 26 b extend substantially parallel to the bottom surface 13 and the top surface 16 of the tank 10. The outer peripheral fin 26b is formed so that the distance from the base end part 26d becomes longer as it is closer to the top surface 16 as compared with the central part of the tank 10 in the height direction. Further, the outer peripheral fins 26b are formed such that the distance from the base end portion 26d is longer as the distance from the top surface 16 is longer than the center portion in the height direction of the tank 10. The outer peripheral fins 26b are formed so as to face the pair of opposing wall surfaces 14 of the tank 10 with a predetermined interval.

The outer wall portion 26 in the base end portion 26d between the adjacent pair of outer peripheral fins 26b is formed near the heat generating portion 21c of the heater 21 as compared with the outer wall portion 26 in other portions. Thereby, since the warm water which flows through the outer periphery flow path 28 can be brought close to the heat generating part 21c of the heater 21, the heat exchange efficiency between the heating part 22 and the warm water can be improved. Further, all the base end portions 26d in the heating unit 22 are formed such that the distance from the heater 21 is substantially constant.

The number of outer peripheral fins 26b is larger than that of inner peripheral fins 25a. Thereby, the heat transfer area of the outer heat exchange surface 26c is larger than that of the inner heat exchange surface 25c. The length of the outer peripheral fin 26b is longer than that of the inner peripheral fin 25a. Thereby, the performance which heats warm water can be ensured, without impairing the moldability at the time of carrying out the die-cast shaping | molding of the heating part 22. FIG.

As described above, the heater unit 20 includes the heating unit 22 formed so as to cover the periphery of the heater 21. The heating unit 22 includes an inner heat exchange surface 25c formed on the inner surface of the through hole 25 penetrating the inside of the heat generating unit 21c, and an outer heat exchange surface 26c formed on the outer wall portion 26 on the outer periphery of the heat generating unit 21c. Have. In the heater unit 20, since the surface area of the heating unit 22 is a heat transfer area for performing heat exchange with the hot water, the total surface area of the inner heat exchange surface 25c and the outer heat exchange surface 26c is the heat transfer area. Become. Therefore, compared with the case where the heater 21 and warm water are made to contact directly, the heat transfer area for heat exchange with warm water can be enlarged.

4, the outer peripheral fins 26 b may be formed radially toward the outer periphery, and the inner peripheral fins 25 a may extend substantially parallel to the top surface 16 of the tank 10. In this case as well, the heat transfer area for heat exchange with hot water can be increased. The plurality of inner peripheral fins 25 a may be formed so as to be substantially parallel to each other, and may not be substantially parallel to the top surface 16 of the tank 10. Further, both the inner peripheral fins 25 a and the outer peripheral fins 26 b may be formed radially, and both the inner peripheral fins 25 a and the outer peripheral fins 26 b may extend substantially parallel to the top surface 16 of the tank 10.

As shown in FIGS. 3 and 4, the connecting portion 29 has a smaller cross-sectional area than the second connecting portion 29 c where the first connecting portion 29 b connected to the heating portion 22 is connected to the top surface 16. Formed. Thereby, the heat of the heater 21 is suppressed from being transmitted to electronic components such as IGBTs 34 and 35 to be described later via the top surface 16.

The heat dissipating fins 29a extend substantially parallel to the bottom surface 13 and the top surface 16 of the tank 10 in the same manner as the outer peripheral fins 26b. Since the heat radiating fins 29a are provided, the heat transmitted from the heating unit 22 via the first connecting portion 29b is radiated to the hot water in the outer peripheral flow path 28, so that the heat of the heater 21 passes through the top surface 16. Transmission to electronic components such as IGBTs 34 and 35 to be described later is further suppressed.

As shown in FIG. 2, the top plate 23 is formed longer in the axial direction of the heater unit 20 than the opening 15 of the tank 10. A connector (not shown) for connecting the fluid heating device 100 to a power supply device or a host controller (not shown) mounted on the vehicle is provided at a portion of the top plate portion 23 that protrudes from the tank 10.

The top plate 23 is welded to the outer peripheral edge of the opening 15 in a state where the heater unit 20 is inserted into the tank 10. The top plate portion 23 forms the top surface 16 of the tank 10. The top surface 16 faces the bottom surface 13 of the tank 10 substantially in parallel.

As shown in FIG. 1, the top plate 23 has a recess 24 a for attaching a bimetal switch 31 as a temperature switch, a recess 24 b for attaching a heater temperature sensor 32, and a recess 24 c for attaching a water temperature sensor 33. And are formed.

The bimetal switch 31 detects the temperature of the heater unit 20 and switches according to the detected temperature. Specifically, the bimetal switch 31 cuts off the supply of power to the heater unit 20 when the temperature of the heater unit 20 rises above the first set temperature. When the temperature of the heater unit 20 falls below a second set temperature that is lower than the first set temperature, the bimetal switch 31 is switched again so that the supply of power to the heater unit 20 is resumed. Also good.

The heater temperature sensor 32 detects the temperature of the heater 21 in the heater unit 20. The heater temperature sensor 32 sends an electrical signal corresponding to the detected temperature of the heater 21 to the control board 40. The control board 40 stops the supply of power to the heater 21 when the temperature of the heater 21 detected by the heater temperature sensor 32 is higher than the set temperature.

The water temperature sensor 33 detects the temperature of the hot water in the vicinity of the discharge port 12 of the tank 10. That is, the water temperature sensor 33 detects the temperature of the heated hot water discharged from the tank 10. The water temperature sensor 33 is provided inside a protrusion 23 a (see FIGS. 2, 3, and 4) that protrudes from the top plate 23 into the tank 10. The water temperature sensor 33 sends an electrical signal corresponding to the detected temperature of the hot water to the control board 40. The control board 40 controls the supply of electric power to the heater 21 so that the temperature of the hot water detected by the water temperature sensor 33 becomes a desired temperature.

As shown in FIG. 2, a pair of IGBTs (Insulated Gate Bipolar Transistors) 34 and 35 as switching elements abut on the top plate portion 23.

The IGBTs 34 and 35 are connected to the vehicle power supply device via the bus bar module 30. The IGBTs 34 and 35 are connected to the control board 40 and perform a switching operation in response to a command signal from the control board 40. The IGBTs 34 and 35 control power supply to the heater unit 20 by a switching operation. Thereby, the heater unit 20 is adjusted to a desired temperature, and the hot water discharged from the discharge port 12 is adjusted to a desired temperature.

The IGBTs 34 and 35 generate heat by repeating the switching operation. The maximum temperature at which the IGBTs 34 and 35 can operate is higher than the temperature of hot water flowing in the tank 10. Therefore, the temperature of the hot water flowing through the tank 10 is transmitted to the IGBTs 34 and 35 through the top plate part 23 and cooled.

As shown in FIG. 1, the bus bar module 30 is stacked on the top plate part 23. The bus bar module 30 is formed in a small rectangle as compared with the top plate portion 23. The bus bar module 30 is a conductive connection member formed of a metal plate capable of supplying electric power and electric signals.

Control board 40 is stacked on top of bus bar module 30. The control board 40 is formed in a small rectangle as compared with the top plate part 23. The control board 40 is electrically connected to the bus bar module 30 and the IGBTs 34 and 35. The control board 40 controls the IGBTs 34 and 35 based on commands from the host controller.

The cover 50 is provided on the upper part of the control board 40. The cover 50 is formed in the substantially same outer peripheral shape as the top plate portion 23. The cover 50 is welded to the outer peripheral edge of the top plate portion 23. The cover 50 seals the internal space between the top plate portion 23.

Next, the operation of the fluid heating apparatus 100 will be described mainly with reference to FIG.

In FIG. 5, the horizontal axis is the distance through which the hot water flowing through the tank 10 flows from the supply port 11 to the discharge port 12, and the vertical axis is the temperature T [° C.]. As shown in FIG. 5, in the fluid heating apparatus 100, hot water having a temperature T ₁ [° C.] supplied from the supply port 11 is heated to a temperature T ₂ [° C.] by a heater unit 20 having a temperature T _h [° C.]. And discharged from the discharge port 12.

The supply port 11 is formed on an extension line of the through hole 25. Therefore, the hot water having the temperature T ₁ is supplied from the supply port 11 and guided to the inner peripheral flow path 27. In the inner peripheral flow path 27, hot water is heated by heat exchange with the inner periphery of the through hole 25 in which the inner peripheral fin 25a is formed. At this time, the warm water is rectified by the inner peripheral fins 25a formed along the flow direction of the warm water.

The hot water that has passed through the inner peripheral flow path 27 collides with the wall surface 14 facing the supply port 11 in the tank 10, changes its direction, and is guided to the outer peripheral flow path 28. As described above, the hot water continuously flows through the inner peripheral flow path 27 and the outer peripheral flow path 28. The hot water flowing through the outer peripheral flow path 28 is further heated by heat exchange with the outer wall main body 26a and the outer peripheral fin 26b. Also at this time, the warm water is rectified by the peripheral fins 26b formed along the flow direction of the warm water. The hot water heated to the temperature T ₂ is discharged from the discharge port 12.

Here, the outer peripheral channel 28 has a larger channel area than the inner peripheral channel 27. Therefore, the flow velocity V ₂ [m / s] of the hot water in the outer peripheral flow path 28 is slower than the flow velocity V ₁ [m / s] of the hot water in the inner peripheral flow path 27. However, the outer wall portion 26 facing the outer peripheral flow path 28 has a larger heat transfer area than the through hole 25 forming the inner peripheral flow path 27. Therefore, as shown in FIG. 5, the temperature rise rate of the hot water in the inner peripheral channel 27 and the outer peripheral channel 28 can be made substantially constant.

According to the above embodiment, the following effects are obtained.

The heater unit 20 has a heating unit 22 formed so as to cover the periphery of the heater 21. The heating unit 22 includes an inner heat exchange surface 25c formed on the inner surface of the through hole 25 penetrating the inside of the heat generating unit 21c, and an outer heat exchange surface 26c formed on the outer wall portion 26 on the outer periphery of the heat generating unit 21c. Have. In the heater unit 20, since the surface area of the heating unit 22 is a heat transfer area for performing heat exchange with the hot water, the total surface area of the inner heat exchange surface 25c and the outer heat exchange surface 26c is the heat transfer area. Become. Therefore, compared with the case where the heater 21 and warm water are made to contact directly, the heat transfer area for heat exchange with warm water can be enlarged.

Further, since the outer peripheral flow path 28 has a larger flow path area than the inner peripheral flow path 27, the flow rate V ₂ of hot water in the outer peripheral flow path 28 is slower than the flow speed V ₁ of hot water in the inner peripheral flow path 27. However, the outer wall portion 26 facing the outer peripheral flow path 28 has a larger heat transfer area than the through hole 25 forming the inner peripheral flow path 27. Therefore, the rate of temperature increase in the inner peripheral channel 27 and the outer peripheral channel 28 can be made substantially constant.

The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

For example, in the above embodiment, the hot water supplied from the supply port 11 flows through the inner peripheral channel 27, then flows through the outer peripheral channel 28, and is discharged from the discharge port 12. Not limited to this, hot water supplied from the supply port 11 may flow through the outer peripheral flow channel 28, then flow through the inner peripheral flow channel 27 and be discharged from the discharge port 12.

This application claims priority based on Japanese Patent Application No. 2015-130748 filed with the Japan Patent Office on June 30, 2015, and Japanese Patent Application No. 2016-021030 filed with the Japan Patent Office on February 5, 2016. The entire contents of this application are hereby incorporated by reference.

Claims (24)

A fluid heating device for heating a fluid,
A heater unit having a heater and a heating unit formed so as to cover the periphery of the heater;
The heating unit is
An inner heat exchange surface that is formed on the inner surface of a through hole that penetrates the inside of the heater and exchanges heat with a fluid;
A fluid heating apparatus, comprising: an outer heat exchange surface formed on an outer wall portion outside the heater to exchange heat with a fluid. The fluid heating device according to claim 1,
A tank for storing the heater unit;
The through hole forms an inner peripheral flow path through which a fluid flows,
The fluid heating device, wherein the outer wall portion forms an outer peripheral flow path through which a fluid flows between the inner wall of the tank. The fluid heating device according to claim 2,
The tank
A supply port through which fluid is supplied;
A fluid heating device having a discharge port through which the fluid is discharged. The fluid heating device according to claim 3,
One of the supply port and the discharge port is a fluid heating device that opens on an extension line of the through hole. The fluid heating device according to claim 4,
The supply port is a fluid heating device that opens on an extension line of the through hole. The fluid heating apparatus according to any one of claims 3 to 5,
The discharge port is a fluid heating device that opens side by side with the supply port on the same surface of the tank. The fluid heating device according to claim 6,
A fluid heating apparatus in which a fluid flows continuously in the inner circumferential channel and the outer circumferential channel. The fluid heating apparatus according to any one of claims 2 to 7,
The said through-hole is a fluid heating apparatus which has an internal peripheral fin which protrudes to an internal periphery. The fluid heating device according to claim 8,
The inner peripheral fin is a fluid heating device formed along a fluid flow direction. The fluid heating device according to claim 8 or 9, wherein
The inner peripheral fin is a fluid heating device formed radially toward the inner periphery. The fluid heating device according to any one of claims 2 to 10,
The said outer wall part is a fluid heating apparatus which has the outer periphery fin which protrudes on an outer periphery. The fluid heating device according to claim 11,
The outer peripheral fin is a fluid heating device formed along a fluid flow direction. The fluid heating device according to claim 11 or 12,
The outer peripheral fin is a fluid heating device formed radially toward the outer periphery. The fluid heating device according to claim 11 or 12,
The tank has a top surface that closes an opening for inserting the heater unit,
The outer peripheral fin is a fluid heating device extending substantially parallel to the top surface. The fluid heating device according to claim 14,
The outer peripheral fin is a fluid heating device in which the distance from the base end portion is longer as it is closer to the top surface than the center portion of the tank. The fluid heating apparatus according to claim 14 or 15,
The outer peripheral fin is a fluid heating apparatus in which the distance from the base end portion is longer as the distance from the top surface is further away from the center portion of the tank. The fluid heating apparatus according to any one of claims 11 to 16,
The fluid heating device, wherein the outer wall portion at the proximal end portion of the outer peripheral fin is formed in the vicinity of the heater. The fluid heating apparatus according to any one of claims 2 to 7,
The through hole has an inner peripheral fin that protrudes to the inner periphery,
The outer wall portion has outer peripheral fins protruding to the outer periphery,
The number of the outer peripheral fins is a fluid heating device that is larger than the number of the inner peripheral fins. The fluid heating apparatus according to any one of claims 2 to 7,
The through hole has an inner peripheral fin that protrudes to the inner periphery,
The outer wall portion has outer peripheral fins protruding to the outer periphery,
The length of the said outer peripheral fin is a fluid heating apparatus long compared with the said inner peripheral fin. The fluid heating apparatus according to any one of claims 2 to 19,
The fluid heating device, wherein the heat transfer area of the outer wall portion is larger than the heat transfer area of the through hole. The fluid heating apparatus according to claim 20,
The fluid heating device, wherein the flow passage area of the outer peripheral flow passage is larger than the flow passage area of the inner peripheral flow passage. The fluid heating apparatus according to any one of claims 2 to 13,
The tank has a top surface that closes an opening for inserting the heater unit,
The heater unit is
A connecting part for connecting the top surface and the heating part;
And a heat dissipating part that protrudes from the connecting part. The fluid heating device according to claim 22,
The connecting portion is a fluid heating apparatus in which a portion connected to the heating portion is formed to have a smaller cross-sectional area than a portion connected to the top surface. 24. The fluid heating apparatus according to any one of claims 2 to 23, wherein:
The heater has a heat generating portion formed in a spiral shape,
The through hole is formed with a small diameter as compared with the inner circumference of the heat generating portion and penetrates along the central axis of the heat generating portion,
The fluid heating device, wherein the outer wall portion is formed with a larger diameter than the outer periphery of the heat generating portion and faces the inner wall of the tank.

Images