Heat exchange module

Abstract

A heat exchange module including a corrugated top heat exchange substrate and a corrugated bottom heat exchange substrate, and tubes that extend in a width direction (W) between the top and bottom substrates in heat exchanging contact with ridges of the substrates. A top and a bottom casing member contacts the substrates and each has a transverse side wall with slits oriented in the transverse direction (T) and accommodating the tubes. The side walls of the top and bottom casing members overlap and are mutually connected by soldering or brazing.

Claims

1. A heat exchange module comprising: a corrugated top heat exchange substrate and a corrugated bottom heat exchange substrate, the substrates being spaced apart in a transverse direction (T), each substrate having ridges and channels that extend in a length direction (L), the channels and ridges of the top substrate extending parallel to the channels and ridges of the bottom substrate, tubes extending in a width direction (W) between the top and bottom substrates, in heat exchanging contact with the ridges, the width direction (W) being oriented transversely to the length direction (L) of the channels and the ridges, from an inflow side to an outflow side, a top and a bottom casing member comprising casing surfaces adjacent the top and bottom substrates and having at the inflow and outflow sides a transverse side wall with slits oriented in the transverse direction (T) and accommodating the tubes, the side walls of the top and bottom casing members overlapping and being mutually connected by soldering or brazing.

2. The heat exchange module according to claim 1, each substrate being connected to a casing member along a casing side edge that is situated along a lower part of a respective casing side wall.

3. The heat exchange module according to claim 1, the tubes at the position of the transverse side walls having a straight section extending in the width direction (W), transversely to the side walls.

4. The heat exchange module according to claim 1, the slits in the side walls comprising at their free end a V-shaped receiving part for guiding of the tubes upon placement of the tubes in the slits.

5. The heat exchange module according to claim 1, the tubes extending along an undulating trajectory with undulations in the width direction (W).

6. The heat exchange module according to claim 1, the undulating trajectory comprising bend parts at a distance (D) from a line that is parallel to the width direction (W), a distance (T) of the two adjacent undulations being between 1.5 and 5 times a width (C) of a channel.

7. The heat exchange module according to claim 1, the position of the ridges of the upper substrate in the width direction (W) corresponding to the position of the channels of the lower substrate.

8. The heat exchange module according to claim 1, the substrates being coated with a platinum group metal.

9. The heat exchange module according to claim 1, further comprising: another heat exchange module comprising: another corrugated top heat exchange substrate and another corrugated bottom heat exchange substrate, the substrates being spaced apart in a transverse direction (T), each substrate having ridges and channels that extend in a length direction (L), the channels and ridges of the top substrate extending parallel to the channels and ridges of the bottom substrate, other tubes extending in a width direction (W) between the top and bottom substrates, in heat exchanging contact with the ridges, the width direction (W) being oriented transversely to the length direction (L) of the channels and the ridges, from an inflow side to an outflow side, another top and another bottom casing member comprising casing surfaces adjacent the top and bottom substrates and having at the inflow and outflow sides a transverse side wall with slits oriented in the transverse direction (T) and accommodating the tubes, the side walls of the top and bottom casing members overlapping and being mutually connected by soldering or brazing, wherein the modules are stacked on top of each other, the bottom surface of the upper casing member being soldered or brazed to the top surface of the lower casing member.

10. A catalyst/steam reforming assembly comprising a heat exchange module comprising: a corrugated top heat exchange substrate and a corrugated bottom heat exchange substrate, the substrates being spaced apart in a transverse direction (T), each substrate having ridges and channels that extend in a length direction (L), the channels and ridges of the top substrate extending parallel to the channels and ridges of the bottom substrate, tubes extending in a width direction (W) between the top and bottom substrates, in heat exchanging contact with the ridges, the width direction (W) being oriented transversely to the length direction (L) of the channels and the ridges, from an inflow side to an outflow side, a top and a bottom casing member comprising casing surfaces adjacent the top and bottom substrates and having at the inflow and outflow sides a transverse side wall with slits oriented in the transverse direction (T) and accommodating the tubes, the side walls of the top and bottom casing members overlapping and being mutually connected by soldering or brazing, exhaust gases being led through the channels and alcohol and steam through the tubes.

11. A vehicle comprising: a combustion engine with cylinders that are connected to a fuel inlet and to an exhaust outlet, the exhaust outlet being in fluid contact with a catalyst/steam reforming assembly comprising a heat exchange module comprising: a corrugated top heat exchange substrate and a corrugated bottom heat exchange substrate, the substrates being spaced apart in a transverse direction (T), each substrate having ridges and channels that extend in a length direction (L), the channels and ridges of the top substrate extending parallel to the channels and ridges of the bottom substrate, tubes extending in a width direction (W) between the top and bottom substrates, in heat exchanging contact with the ridges, the width direction (W) being oriented transversely to the length direction (L) of the channels and the ridges, from an inflow side to an outflow side, a top and a bottom casing member comprising casing surfaces adjacent the top and bottom substrates and having at the inflow and outflow sides a transverse side wall with slits oriented in the transverse direction (T) and accommodating the tubes, the side walls of the top and bottom casing members overlapping and being mutually connected by soldering or brazing, exhaust gases being led through the channels and alcohol and steam through the tubes, an evaporator that is in heat exchanging contact with the exhaust gases, a water and ethanol supply unit flowing water and ethanol through the evaporator for forming water and ethanol steam, the water and ethanol steam being passed into the tubes, and a reformed fuel duct connected to an outflow side of the tubes and being connected to a fuel inlet of the cylinders.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] A heat exchange module according to the disclosure will, by way of non-limiting example, be described in detail with reference to the accompanying drawings. In the drawings:

[0035] FIG. 1 shows a perspective view of a stack of heat exchange modules,

[0036] FIG. 2 shows a perspective view of a side section of a heat exchange module,

[0037] FIG. 3 shows a detail of tubes being received in slits in the sidewalls,

[0038] FIG. 4 shows a perspective view of the tubes and a bottom heat exchange substrate and casing member,

[0039] FIG. 5 shows a plan view of the tubes and the heat exchange substrate,

[0040] FIG. 6 shows the flow of gases around the tubes of the heat exchange module, and

[0041] FIG. 7 shows an embodiment of a vehicle including an ethanol reforming unit including heat exchange modules according to the disclosure.

DETAILED DESCRIPTION

[0042] FIG. 1 shows a stack 1 of interconnected heat exchange modules 2, 3, 4, each module including two spaced-apart corrugated heat exchange substrates 6, 7 with tubes 8 extending in heat exchanging contacting relationship between the substrates. The substrates 6,7 and tubes 8 are encased between top and bottom casing members 10, 11, the casing members having overlapping side walls 12, 13 that are interconnected by brazing or soldering.

[0043] As can be seen in FIG. 2, the top and bottom heat exchange substrates 16,17 have ridges 19, 20 and channels 18, 21 that extend in the length direction Lather tubes 23, 24, 25 extend transversely to the ridges 19, 20 and channels 18, 21 in the width direction W from an inflow side 26 to an outflow side 27 and are clamped between the opposing ridges and channels 18, 19 of the top and bottom heat exchange substrates 16, 17. The tubes 23, 24, 25 pass through the slits 28, 29, 30 in the overlapping sidewalls 32, 33 of the casing members 35, 36. Each slit 28, 29, 30 has a V-shaped end part 37, 38 in which the tubes 23-26 are received and oriented during automated positioning. The tubes 23, 24, 25 are soldered into the slits 28-30 to form a gas-tight enclosure within the casing members 35, 36. The sidewalls 32, 33 are joined in a gas-tight manner by soldering in an overlapping position along their perimeter.

[0044] The heat exchange substrates 16,17 are brazed against the lower edges of the sidewall 33 so that the corrugated parts can slide with respect to the casing members 35, 36 while being kept firmly in place.

[0045] FIG. 3 shows a detail of the tubes 40,41,42 passing through the sidewall 33 via slits 44,45,46 with a V-shaped end part having slanting edges 47, 48. The tubes 40, 41, 42 extend along an undulating path in the width direction W in heat conducting contact with the heat exchange substrate 17. At the position of the sidewall 33, the tubes 8 extend along a straight line to allow easy handling upon insertion into the slits 44, 45, 46 and easy and accurate automated positioning.

[0046] FIG. 4 shows a perspective view of the lower casing member 36 and heat exchange substrate 17, with the tubes 8 supported by the sidewalls 33, 34 and extending from an inflow side 26 to an outflow side 27. A number of 30-500 tubes may be accommodated in the arrangement shown. The undulating path of the tubes causes turbulence of the gases flowing in the length direction L, over and under the tubes, through the channels of the heat exchange substrates for improved heat transfer.

[0047] FIG. 5 shows the width C of the channels 20,21 and the amplitude D and period T of the undulating tubes 8. The values of C, D and T are carefully tuned to result in optimal heat transfer of gases flowing through the channels 20,21 in the direction F, and a fluid substance flowing through the tubes 8 in a crossflow manner. C:D: T may be about 1:1:5.

[0048] FIG. 6 shows the flow of gases flowing through the channels of the upper and lower heat exchange substrates 16, 17 while passing over and under the tubes 8. The turbulent flow pattern results in good heat exchange properties.

[0049] FIG. 7 shows an internal combustion engine assembly 41 with an internal combustion engine 42 having four cylinders 43. A fuel inlet 44 supplies a fuel, that may contain bio-ethanol, for instance in the form of an E10, to the cylinders 43.

[0050] A turbocharger 48 compresses the air that is supplied from an air intake 49 and transports the intake air through a cooler 45 to the intake manifold 51 for supply to the cylinders 43. The exhaust gases of the fuel that has been burned in the cylinders 43, leave the engine 42 via an exhaust manifold 52 and flow through an exhaust duct 56 to drive the turbocharger 48. After passing through the turbocharger 48, the exhaust gases flow via the duct 53 into an integrated catalytic converter/fuel reformer unit 54 that is formed from stacked heat exchange modules that are described in FIGS. 1 to 4. Via an exhaust duct 56, the exhaust gases pass to an ethanol evaporator 57 and from there via exhaust duct 58 to a tail pipe to be expelled into the ambient.

[0051] A pump 63 is connected to a water/ethanol tank 64 and supplies water and ethanol from the tank 64 to the evaporator 57 where the water/ethanol, that is at ambient temperature, is brought in heat exchanging contact with the exhaust gases. The ethanol steam and water steam that is produced in the evaporator 57, is supplied via a duct 61 to a pre-heater/cooler unit 75.

[0052] The pre-heated water steam and ethanol steam mixture is fed from the unit 75 to the integrated catalytic converter/fuel reformer unit 54 through duct 76, where the water and steam are flowing through the tubes 8 shown in FIGS. 1-4, of the reformer unit 54, to be reformed into syngas. The exhaust gases flow through the channels of the heat exchange substrates. The tubes 8 may be coated with a PGM to activate the reforming process. The coating of the tubes may have a different specification of PGM than the coating of the heat exchange substrate, that forms a TWC for the removal of NOx and hydrocarbons from the exhaust gases.

[0053] The exhaust gases flow from the duct 53 in the reformer unit 54 through the channels 20,21 of the top and bottom heat exchange substrates 6,7; 16,16 that are shown in FIGS. 1 and 2.

[0054] The syngas that is formed in the integrated catalytic converter/fuel reformer unit 54 is transported via a syngas outlet duct 77, through the pre-heater/cooler unit 75 and preheats the water and ethanol by being brought in heat exchanging contact with the water/ethanol steam that is supplied at the inlet of the unit 75.

[0055] Via an outlet duct 80 and a reduction valve 81, the syngas is supplied to a gas inlet manifold 85 that is connected to the cylinders 3.