DE102004027001A1 - heat exchangers - Google Patents

Abstract

A heat exchanger comprises a plurality of laminated or laminated tubes (131) through which a refrigerant flows from a fuel cell (10); Ribs (132) are disposed between the tubes and on the outermost sides in the laminating direction of the tubes, core plates (134) connected to the longitudinal parts of the tubes, and tank members (110, 120) fixed to the core plates to form tank spaces. The tubes are made of a first insulating material, and the ribs and the core plates are bonded to or bonded to the tubes using metallic parts provided separately on surfaces of the tubes. In addition, a coating member (150) having a second insulating material is provided on surfaces of the core plates at least at an exposed position of the core plates and at locations around soldering portions of the core plates to be connected to the tubes. Thus, the heat exchanger can be isolated from the fuel cell without using an electrically insulating liquid.

Description

AREA OF INVENTION

The The invention relates to a heat exchanger for cooling a fuel cell for a fuel cell powered vehicle. In the heat exchanger can cooling water as a coolant Find use.

BACKGROUND THE INVENTION

In a cooling system a fuel cell described in JP-A-2002-33108 (corresponding to US Patent Application Publication 2002/31693), is a radiator (heat exchanger) in a coolant circulation channel provided, through which a coolant is circulated in the fuel cell. As a coolant is still a electric liquid Insulating material used. The electrical liquid insulating material is, for example fluorine-inert (manufactured by Sumitomo 3M) from a fluoride-inert liquid, or it is an insulating oil. Furthermore, an insulating Material interposed between the fuel cell and the coolant circulation channel or the coolant circulation channel is formed of an insulating material, so that the radiator is electrically is isolated from the fuel cell.

The electrical insulating fluid, such as the fluoro-inert agent, has a low electrical Conductivity, compared to a general coolant such as water or ethylene glycol. It is therefore difficult to sufficiently improve the cooling performance in the radiator. Furthermore, the manufacturing cost of the cooling system of the fuel cell improved because the electrically insulating liquid like the fluorine-inert Medium is expensive compared to a general coolant.

each Component of the radiator can be molded from an insulating material be to insulating performance in the radiator, while the general coolant used will be available to deliver. In this case, however, the thermal conductivity of the radiator becomes considerable deteriorated; It is difficult to have a necessary cooling capacity in the radiator to obtain.

SUMMARY PRESENTATION OF THE INVENTION

in the In view of the above problems, it is an objective of the present Invention, a heat exchanger to disposal to be isolated against a fuel cell, without that uses an electrically insulating liquid as a coolant will, while the cooling capacity of the heat exchanger not severely impaired becomes.

According to the invention a heat exchanger a plurality of tubes through which a coolant from a fuel cell to carry out the heat exchange flows, a plurality of ribs adjacent to the tubes and the outermost ones. Side of the pipes in the laminating or laminating direction of the pipes seen, are arranged and for binding to the pipes or for connection with these are intended, one connected to a longitudinal end portion of each tube Core plate and a resin tank element. These pipes are made of a first insulating material, the tank element attached to the core plate on one side, which are related to the tubes on the core plate opposite lies; the tank element and the core plate are for forming a attached to the tubes related tank room. In the heat exchanger feature the pipes over a variety of metallic parts, which face each other on outer surfaces of the tubes are separated; the ribs and the core plate are soldered to the Outside surfaces of the Tubes tied to the metallic parts. Because the metallic parts from each other on the outer surfaces of the pipes separated, it becomes possible electrically the ribs and tube parts, those with the ribs in the heat exchanger are insulated, even if a liquid enclosing water as a coolant Use finds. About that In addition, the heat exchanger performance be improved by the ribs of metallic material.

Prefers becomes a coating part with a second insulating material on a surface of the core plate, the Tank room opposite lies, covered. In general features the core plate over an exposed part that protrudes against the outside of the pipes Seen (side plates) is exposed and soldering are to the pipes soldered. In this case, the coating part is at least on the exposed part as well as in places around the soldering parts provided the core plate. So lets the Isolierlei Stung on the outside of the heat exchanger Effectively improve, even if cooling water as a coolant Use finds.

In the heat exchanger, first and second side plates are generally provided at the outermost ribs in the direction of lamination, lamination or stacking, hereinafter referred to as lamination, for reinforcement and extend in the tube longitudinal direction. At least one of the longitudinal end portions of each side plate is made of the first insulating material. Moreover, the one longitudinal end part of each side plate has a soldering part soldered to the core plate by a metallic part resting on a surface of the longitudinal end part of each Side plate is provided, the coating member is disposed at a position around the soldering portion of each side plate around. Therefore, the outside of the heat exchanger can be accurately insulated against the fuel cell.

Prefers is the soldering part of the longitudinal end part each side plate separated from points where the tubes to the core plate soldered are. In this case lets improve the insulation performance of the side plate.

According to the invention are a first metallic part bound to the ribs and a second metallic one provided on the core plate bound portion on the outer surface of each tube, around each other on the outside surface of each Tube to be separated. An uncovered part of the first insulating material is on the outer surface of each tube between the formed second metallic part and the first metallic part. Thus lets the insulation performance of the heat exchanger is fast improve.

SUMMARY THE DRAWINGS

For example embodiments The invention will now be described with reference to the accompanying drawings be explained in more detail, in which

1 shows a schematic representation of a fuel cell system with a fuel cell and a radiator (heat exchanger) according to the preferred embodiment of the invention;

2 a front view of the in 1 to see radiator; and

3 is a cross section that reveals the main part of the radiator according to the embodiment.

LONG DESCRIPTION THE PREFERRED EMBODIMENT

A preferred embodiment of the invention will now be described with reference to FIGS 1 to 3 be explained in more detail. An in 1 The fuel cell system shown includes a fuel cell 10 mounted on a fuel cell powered vehicle and a radiator 100 for cooling the fuel cell 10 , A drive motor for the vehicle is driven by using the fuel cell as an electric power source. The radiator 100 cools the coolant (cooling water) that is in the fuel cell 10 circulates so that the temperature of the fuel cell is controlled.

The fuel cell 10 is constructed with fuel cell stack assemblies composed of multiple cells, as well as outer housings that receive the fuel cell stacks. Each of the cells of the fuel cell stack is formed by introducing an electrolyte film between a positive electrode and a minus electrode, so that electric current is generated by chemical reaction between hydrogen and oxygen.

As in 1 shown is a radiator circulation circuit 20 of an insulating material with the outer casing of the fuel cell 10 connected in two places. For example, the radiator circulation channel 20 defined by a rubber hose made of an insulating rubber material. radiator 100 as well as a water pump 21 are in the radiator circulation channel 20 arranged in the refrigerant flow direction in this order. By the operation of the water pump 21 The coolant circulates in the outer casing of the fuel cell 10 in the radiator circulation channel 20 and the radiator 100 like the arrows in 1 reveal. The coolant is an antifreeze liquid obtained by mixing ethylene glycol in water, for example. This antifreeze fluid is generally used as a coolant in known gasoline powered vehicles.

A bypass channel 22 through which the coolant the radiator 100 bypasses in the bypass, is in the radiator circulation channel 20 parallel to the radiator 100 intended. The bypass channel 22 is defined by a rubber hose made of an insulating rubber material, for example. A valve 23 is seen at a union part before, where the radiator circulation channel 20 on a downstream side of the radiator 100 and a downstream side of the bypass channel 22 getting together. The operation of the valve 23 is regulated by a control unit (not shown), so that a flow ratio between a quantity of refrigerant passing through the radiator 100 goes and a quantity of coolant passing through the bypass channel 22 goes, can be adjusted. The valve 23 may be provided at a union part where the radiator circulation channel 20 on an inflow side of the radiator 100 and an upstream side of the bypass channel 22 getting together.

A reserve tank 24 is in the radiator 100 to absorb an expansion volume portion of the coolant as the temperature of the coolant increases and to supply a volume contraction portion of the coolant to the radiator as the temperature of the coolant decreases.

The radiator 100 has a core part 130 , an upper tank element 110 and a lower tank element 120 , The radiator 100 is of type vertical flow, in which the coolant in pipes 131 of the core part 130 flows vertically. In the 2 and 3 For example, the coolant flows through the pipes 131 from the upper tank element (bottom) 110 down against the lower tank element (bottom) 120 , The core part 130 is made of a variety of flat tubes 131 , several ribs 132 , two side plates 133 and two upper and lower core plates 134 built up.

Each of the ribs 132 is a corrugated rib shaped in wavy shape by bending a thin sheet. The pipes 131 and the ribs 132 are alternately stacked (laminated) in a lamination direction. The side plates 133 are at the outermost ribs 132 (right and left extreme side in 2 ) of the stacked element for reinforcing the core part 130 attached. The side plates 133 are fixed so that they are in a longitudinal direction of the tubes 131 extend.

Each of the core plates 134 is with holes 134a provided for the tubes, in which the one end portions of the tubes 133 introduced, as well as holes for side plates 134b , in which the one end portions of the side plates 133 be introduced. In addition, the core plates have 134 over tank inlet parts 134c at its outer peripheral part, in which outer peripheral parts of the upper and lower tank members 110 . 120 be introduced so that tank spaces in connection with the pipes 131 be formed. Furthermore, a variety of claw parts 134d for fixing the upper and lower tank elements 110 . 120 in the core plate 134 on the outsides of the tank inlet parts 134c intended.

The upper tank element 110 and lower tank element 120 are made of a resin material such as nylon, including glass fibers, and have heat resistance and sufficient strength. Each from upper tank element 110 and lower tank element 120 is formed in a cross-section approximately of U-shape. An open end of the tank element 110 . 120 is the core plate 134 opposite and is with the core plate 134 connected to the formation of the tank room.

As 3 becomes a seal element 140 (Packing seal) between the outer peripheral part of each tank element 110 . 120 around the opening side of each tank element 110 . 120 and the tank introduction part 134c the core plate 134 introduced, and every tank element 110 . 120 is mechanical with each core plate 130 using claws 134d connected.

An inlet pipe 111 , a coolant fill port 112 and mounting fittings 113 are in the upper tank element 110 integral with the upper tank element 110 intended. In contrast, an outlet pipe 121 and fitting parts 122 in the lower tank element 120 in one piece with the lower tank element 120 intended. The inlet pipe 111 through which the coolant in the radiator circulation channel 20 in the upper tank 110 of the radiator 100 is with the radiator circulation channel 20 connected, and the outlet pipe 121 through which the coolant enters the lower tank element 120 to the radiator circulation channel 20 Is discharged with the radiator circulation channel 20 connected. Thus, the coolant flows in the radiator circulation passage 20 in the upper tank element 110 from the inlet pipe 111 , flows through the pipes 131 the core parts 130 and will be in the lower tank element 120 collected. Then that will be in the lower tank element 120 collected coolant from the radiator 100 through the outlet pipe 120 flow out.

Next, the main part of the present invention will be described. In this embodiment, the ribs are 132 and the core plate 134 made of a substantially thermally conductive material (metallic material) such as aluminum or an aluminum alloy. The pipes 131 and the side plates 133 are made of a ceramic material (first insulating material) with electrical insulating performance. For example, the pipes 131 and the side plates 133 made of a ceramic material with a high purity alumina as the main material. Each of the pipes 131 and each of the side plates 133 are formed by firing after being molded by extrusion. Let's get the dimensions of the pipes 131 and the side plates 133 not set exactly by burning, so after firing, if necessary, followed by a polishing process.

The surface of each tube 131 can with a first metallic part 131 around the tube holes 134a the core plate 134 and a second metallic part 131b , the ribs 132 contacted, be provided. The metallic parts 131 . 131b are formed by placing a metallic layer on the ceramic surface of the tubes 131 is applied. The metallic parts 131 . 131b can be applied to the ceramic surface by a direct or indirect metallization process or a fusion bonding process. Furthermore, an Al-Si type solder material may be provided on the surfaces of the metallic parts 131 . 131b be trained to fast the pipes 131 with the ribs 132 and the core plates 134 to bind or connect. The metallic parts 131 . 131b are on the outside surface of the pipes 131 of ceramic material to be separated from each other. Therefore, the outer surface of the tube features 131 over uncovered parts (exposed areas) without the metallic ones parts 131 . 131b between the metallic parts 131 and 131b , In addition, the metallic parts 131b provided on the outer surface of each tube, which are to be separated from each other, so that uncovered parts between the metallic parts 131b revealed, and the metallic parts 131 are on the outside surfaces of the pipes 131 which are to be separated from each other.

The surface of each side plate 133 can with first metallic parts 133b which are the outermost rib 132 contact, as well as with second metallic parts 133a around the side plate holes 134b the core plates 134 be provided. Similar to the pipes 131 is the metallic part 133b on the outer surface of the side plate 133 to see from the second metallic parts 133a to be disconnected. In addition, the second metallic part 133a standing on the outside surface of the side plate 133 is provided by the metallic part 131 separated on the outer surface of each tube 131 is provided.

Through the metallic parts 131 . 131b . 133a and 133b can the pipes 131 to the core plates 134 and the ribs 132 each soldered, and the side plates 133 can connect to the core plates 134 and the ribs 132 each in the core part 130 be soldered.

Furthermore, a coating part 150 by a resin material (second insulating material) on the outer surface of the core member 134 at least at the exposed part and at locations around the soldering parts of the core plate 134 applied around where the pipes 131 and the side plates 133 be introduced to the core plate 134 to be soldered. Here is the exposed part of the core plate 134 that's against the outside of the side plates 133 and the pipes 131 is free. For example, the coating part 150 coated with resin using a silicone material (second insulating material). As in 3 to see is the coating part 150 on the outer surface opposite the tank space of the tank element 120 . 130 applied.

In the fuel cell 10 Electricity is generated by the chemical reaction between hydrogen and oxygen delivered to both electrodes. Heat generated during electric power generation is transmitted to the coolant (cooling water) and flows into the radiator 100 by the operation of the water pump 21 through the radiator circulation channel 20 , That through the radiator 100 flowing coolant is cooled and the coolant is introduced into the fuel cell 10 circulates so that the temperature of the fuel cell 10 is regulated. If the amount of generated electric current or electric power of the fuel cell is low, the coolant flows out of the fuel cell 10 through the bypass channel 22 under bypass of the radiator 100 , actuated by the switching valve 23 , Here is the flow rate of the through the radiator 100 adjusted coolant flow, so that the temperature of the fuel cell 10 during operation of the fuel cell 10 can be controlled in a suitable temperature range. In general, the radiator cools 100 the refrigerant to become equal to or lower than a predetermined temperature (for example, 80 ° C).

Will the operation power generation of the fuel cell 10 executed, a high voltage is applied to the coolant (cooling water). In this embodiment, the tubes 131 and the side plates 133 made of an insulating material such as the ceramic material. Furthermore, the metallic parts 131b on the surfaces of the pipes 131 that with the ribs 132 to be connected, from the metallic parts 131 disconnected with the core plate 134 are connected; and the metallic parts 133b on the surfaces of the side panels 133 that with the ribs 132 To be connected are those with the core plate 134 to be joined metallic parts 133a separated. In addition, the coating part 150 of an insulating material on the outer surface of the core part 134 on the exposed parts of the core plate 134 exposed to an outside and the parts around the soldering portions (connecting portions) of the core plates 134 provided where the pipes 131 and the side plates 133 to the core plates 134 are soldered. Even if the high voltage coolant in the radiator 100 flows, the high-voltage coolant from the outside of the radiator 100 isolate. It is thus unnecessary to use the electrical insulating liquid as a coolant. Thus, cooling water can be used as coolant in the radiator 100 Find use.

In this embodiment, the pipes can be 131 and the side plates 133 with the ribs 132 made of metallic material such as aluminum or aluminum alloy by soldering, the metallic parts 131b . 133b Use find separately on the outer surfaces of the tubes 131 and the side plates 133 are provided. Thus, if the coating part 150 not in the places around the soldering areas of the core plate 134 are provided, and even if a coolant such as cooling water is used, the isolation of the ribs can be 132 and the pipes 131 to reach.

Because in a wide range in the radiator 100 contained ribs 132 not made of insulating material, but isolated, must be made, can the heat transfer performance in the radiator 100 improve and the cooling capacity for cooling the coolant in the radiator 100 can be effectively increased.

Incidentally, the side plates 133 made of a ceramic material and against the outermost ribs 132 connected in laminating or laminating direction, similar to the tubes 131 , The radiator 100 can thus be reinforced while the coolant (cooling water) in the radiator 100 from the outside of the radiator 100 can be isolated.

In this embodiment, even if any of the tubes 131 or the side plates 133 to the core plate 134 is not soldered and provides a non-connection part, the non-connection part through the coating part 150 closed. Thus, the coating part 150 also as a sealant between the pipes 131 , the side plates 133 and the core plates 134 be used.

Other Embodiments

Even though the invention with reference to preferred embodiments with reference to the accompanying Drawings explained has to be noted that various changes and modifications for the expert is obvious.

For example, in the embodiment described above, the side plate 133 be formed so that it has a first part of a ceramic material and a second part of an aluminum material. Here, the first part is a part around a soldering area, with the core plate 134 is soldered, and the second part or area is the other area or part of the side plate 133 except the first part or area. In this case, the metallic on the side plate 133 provided part 133b the above-described embodiment are omitted.

For example, when the heat exchanger is installed in a vehicle while an outer portion of the core plate 134 is covered by an insulating member, the outer surface of the heat exchanger can be isolated with respect to the coolant, even if the coating member 150 is not provided.

In the above-described embodiment of the present invention, the coating area becomes 150 (Coating layer) on the core plate 134 applied in places around the binding parts of the core plate as a coating where the longitudinal end parts of the tubes 131 with the core plate 134 get connected. However, according to the invention, because the metallic parts 131b on the pipes 131 are provided so that they are from the metallic parts 131b on the pipes 131 can be separated, the coating area 150 at the locations around the pipe connection areas of the core plate 134 be omitted. Next are the metallic parts 131b on the pipes 131 that with the ribs 132 to be connected, from the metallic part 131 on the pipes 131 that with the core plate 134 to be connected separately.

The ceramic (top) surfaces of the pipes 131 are exposed to the outside between the metallic parts 131b and the metallic parts 131 , Thus, the ribs can 132 and the main parts of the ribs 132 connected electrically insulated pipes.

In the embodiment described above, the present invention is typically applied to the heat exchanger with upper and lower tank elements 110 . 120 (Floors) and the upper and lower core plates 134 applied. However, the invention can also be applied to a heat exchanger alone with a side tank and a side core plate. Furthermore, in the embodiment described above, the upper and lower tank elements extend 110 . 120 as well as the core plates 134 roughly horizontal. However, the invention can also be applied to a heat exchanger where the tank elements 110 . 120 and the core plates 134 extend approximately vertically or extend in a direction that crosses with the horizontal direction.

Such changes and modifications are considered to be within the scope of the invention, such as it is defined in particular in the appended claims.

Claims (12)

A heat exchanger comprising: a plurality of pipes ( 131 ), by which a coolant from a fuel cell ( 10 ) for carrying out the heat exchange, wherein the tubes are laminated in a lamination direction and made of a first insulating material; a variety of ribs ( 132 ) disposed adjacent to the tubes and the outermost sides of the tubes in the lamination direction to be connected to the tubes; a core plate ( 134 ) connected to a longitudinal end portion of each pipe; and a tank element ( 110 . 120 ) of resin, wherein the tank member is fixed to the core plate on a side opposite to the tubes with respect to the core plate, and the tank member and the core plate are fastened to each other so as to form a tank space communicating with the tubes in which: the tubes pass over a plurality of metallic parts ( 131 . 131b ), which face each other on the outside Surfaces of the tubes are separated; and the ribs and the core plate are connected to the metallic parts by soldering to the outer surfaces of the tubes. Heat exchanger according to claim 1, further comprising: a coating part ( 150 ) provided with a second insulating material on a surface of the tank facing the core tank plate, wherein: the core plate has an exposed portion exposed to the outside as seen from the tubes and soldering portions the pipes are soldered; and the coating member is provided at least on the exposed part and at locations around the soldering portions of the core plate. Heat exchanger according to claim 2, further comprising: first and second side plates ( 133 ) disposed at the outermost ribs in the lamination or laminating direction for reinforcement and extending in a longitudinal direction of the tubes, wherein: at least one longitudinal end portion of each side plate is made of this first insulating material; a longitudinal end part of each side plate has a soldering area, which against the core plate by a metallic part ( 134b ) soldered on a surface of the longitudinal end portion of each side plate; and the coating member is provided on the core plate at a location around the soldering portion of each side plate. Heat exchanger according to one of claims 1 and 2, further comprising: first and second side plates ( 133 ) provided at the outermost ribs in lamination or lamination direction for reinforcement to extend in a longitudinal direction of the tubes, wherein: at least one longitudinal end portion of each side plate is made of the first insulating material; a longitudinal end part of each side plate has a soldering area, which against the core plate by a metallic part ( 134b ) is soldered on a surface of the longitudinal end portion of each side plate; and the soldering portion of the longitudinal end portion of each side plate is separated from locations where the tubes are brazed against the core plate. Heat exchanger according to one of claims 1 and 2, further comprising: first and second side plates ( 133 ) disposed at the outermost ribs in a laminating or laminating direction for reinforcement and extending in a longitudinal direction of the tubes, wherein: all the side plates are made of the first insulating material; and each of the side plates further comprises a first metallic part ( 133b ) provided on the surface to be connected to the outermost rib, and a second metallic part ( 133a ) is provided separately from the first metallic part on its surface, which is to be connected to the core plate. A heat exchanger comprising: a plurality of pipes ( 131 ), through which a coolant from a fuel cell ( 10 ) for carrying out the heat exchange, wherein the tubes ( 131 ) are laminated in a laminating direction and made of a first insulating material; a variety of ribs ( 132 ) disposed between adjacent the tubes and the outside of the tubes in lamination or laminating direction to be connected to the tubes; a core plate ( 134 ) connected to a longitudinal end portion of each pipe; a tank element ( 110 . 120 ) of a resin, wherein the tank member is fixed to the core plate on the side opposite to the tubes with respect to the core plate, and the tank member and core plate are fixed with respect to each other to form a tank space communicating with the tubes; a plurality of first metallic parts ( 131b ) provided on outer surfaces of the tubes in connection with the ribs; and a plurality of second metallic parts ( 131 ) provided on the outer surfaces of the tubes for connection to the core plate, and the second metallic parts being provided on the outer surfaces of the tubes to become separated from the first metallic parts. Heat exchanger according to claim 6, wherein the first metallic parts ( 131b ) are provided on the outer surfaces of the tubes to be separated from each other; and the second metallic parts ( 131 ) are provided on the outer surfaces of the tubes to be separated from each other. heat exchangers according to claim 6, wherein the first metallic part and the second metallic part on the surface Each tube is provided so that it forms part of the outer surface of each Cover tube and an uncovered part between the second leave metallic part and the first metallic part. A heat exchanger comprising: a plurality of pipes ( 131 ), through which a coolant from a fuel cell ( 110 ) for performing the heat exchange, the tubes are laminated in a laminating or laminating direction and made of a first insulating material; a variety of ribs ( 132 ), between be adjacent the tubes and the outermost sides of the tubes in the laminating direction to be connected to the tubes; a core plate ( 134 ) connected to a longitudinal end portion of each tube; a tank element ( 110 . 120 ) of a resin, wherein the tank member is fixed to the core plate at a side opposite to the tubes with respect to the core plate, and the tank member and core plate are fixed to form a tank space communicating with the tubes; a first metallic part ( 131b ) provided on an outer surface of each tube for connection to the ribs; and a second metallic part ( 131 ) provided on the outer surface of each tube for connection to the core plate to have an uncovered portion on the surface of each tube between the second metallic portion and the first metallic portion. heat exchangers according to one of the claims 1 to 9, wherein the first insulating material is a ceramic material is. heat exchangers according to one of the claims 1 to 10, wherein the core plate and the ribs of a metallic Material are made. heat exchangers according to one of the claims 1 to 11, wherein the tank element and the core plate at both Längsendteilen each tube forming a tank space on two long sides the tubes are arranged.