Monocast heat exchanger

专利摘要:
A heat exchanger comprises a combustion chamber, a plurality of parallel flue gas channels and a plurality of water channels each provided in between a first and a second cast wall. Intermediate walls connect the first with the second cast wall, creating a meandering water channel between the first and the second cast wall. The first and the second cast walls comprise- in the direction of flue gas flow- a first, a second and a third section with pins protruding into the flue gas channel. In each of the three sections, the pins are provided according to specific arrangements for increased performance of the heat exchanger.
公开号:NL2021224A
申请号:NL2021224
申请日:2018-07-02
公开日:2019-01-10
发明作者:Tashacori Hasan；Bus Marc
申请人:Bekaert Combustion Tech Bv；
IPC主号:

专利说明:

Description
Technical Field
The invention relates to the field of monocast heat exchangers having a plurality of flue gas channels parallel to each other and a plurality of water channels parallel to each other.
Background Art
EP0889292A1 discloses a heat exchanger designed as a monocasting from substantially aluminium. The heat exchanger comprises a number of walls. The walls bound on one side a water-carrying channel and on the other side a burner space and at least two parallel flue gas drafts. The flue gas drafts extend from the burner space. The burner space is intended for accommodating a burner. The walls which bound the burner space and the flue gas drafts are water-cooled as the water-carrying channel extends along the burner space and along the flue gas drafts. Pins are provided on the walls. The pins extend in the flue gas drafts in order to increase heat transfer from the flue gas drafts to the water flowing through the watercarrying channel.
Disclosure of Invention
The first aspect of the invention is a monocast heat exchanger. The monocast heat exchanger comprises a combustion chamber for the generation of flue gas and a plurality of flue gas channels, parallel to each other, extending from the combustion chamber for flue gas to flow from the combustion chamber. The monocast heat exchanger further comprises a plurality of water channels, parallel to each other, for the flow of water to be heated by heat exchange from the flue gas flowing through the flue gas channels. Each of the water channels is provided in between a first cast wall and a second cast wall. In between each first cast wall and each second cast wall intermediate walls are provided connecting the first cast wall with the second cast wall, thereby creating a meandering water channel between the first cast wall and the second cast wall. Each of the first cast walls and each of the second cast walls are in heat exchange contact each with one of the flue gas channels. The first cast walls and the second cast walls each comprise a first section with pins protruding into the flue gas channel, a second section with pins protruding into the flue gas channel and a third section with pins protruding into the flue gas channel. The second section is provided in flue gas flow direction downstream from the first section. The third section is provided in flue gas flow direction
-2downstream from the second section. In the first section each pin protruding from the first wall is aligned with a pin from the second wall such that a gap is provided between the tip of the pin protruding from the first wall and the tip of the pin with which it is aligned and which protrudes from the second wall. With pins are aligned is meant that pins that are aligned have coinciding axes. In the first section the length of each pin protruding from the first wall is equal to the length of the pin protruding from the second wall with which it is aligned. The second section comprises first pins protruding from the first cast wall, second pins protruding from the second cast wall, third pins protruding from the first cast wall and fourth pins protruding from the second cast wall. The first pins and the fourth pins have the same length. The second pins and the third pins have the same length. The first pins are longer than the second pins. Each first pin is aligned with a second pin, such that a gap is provided between the tip of the first pin and the tip of the second pin with which it is aligned. Each third pin is aligned with a fourth pin, such that a gap is present between the tip of the third pin and the tip of the fourth pin with which it is aligned. In the third section fifth pins are provided extending over the full distance between the first cast wall and the second cast wall. The fifth pins protrude from the first cast wall and from the second cast wall.
The heat exchanger of the invention has the benefit that a high capacity (as expressed in kW) is achieved for the amount of metal that is required for the casting operation to manufacture the monocast heat exchanger, in combination with a high efficiency of heat exchange between flue gas and the water to be heated.
In a preferred embodiment, the first pins, the second pins, the third pins and the fourth pins all have the same diameter.
Preferably, the pins in the first section have a larger diameter than the pins in the second section.
Preferably, the pins in the second section have the same diameter as the pins in the third section.
In a preferred embodiment, the pins in the first section have a larger diameter than the pins in the second section; and the pins in the third section have the same diameter as the pins in the second section.
Preferably, the monocast heat exchanger is cast out of aluminium or out of an aluminium alloy.
Preferably, the combustion chamber is provided for the installation into it of a fully premixed surface stabilized burner for the generation of flue gas in the combustion chamber.
In a preferred monocast heat exchanger, first pins and third pins alternate on the first cast wall in the second section. Second pins and fourth pins alternate on the second cast wall in the second section.
-3Preferably, in the first section, the pins on the first wall and the pins on the second wall are arranged in rows of pins. The rows are perpendicular to the flue gas channel. The pins in the rows in flue gas flow direction more downstream are longer than the pins in the rows in flue gas flow direction more upstream.
Preferably, the first section comprises rows of pins provided perpendicularly to the flue gas channel. Each row of pins has a gap length. The gap length is defined as the distance between the tips of pins protruding from the first wall and the tips of pins protruding from the second wall. The gap length decreases in flue gas downstream direction. The difference in gap length is larger between each row of pins and its in flue gas flow direction previous row of pins than between each row of pins and its in flue gas flow direction next row of pins.
In a preferred monocast heat exchanger, the pins in the first section, in the second section and in the third section are provided on the first walls and on the second walls according to regular patterns. On the first wall, in the first section, in the second section and in the third section, the regular patterns are interrupted by missing pins. More preferably, the regular patterns are interrupted in a regular way by missing pins. Even more preferably, the regular way of missing pins is provided by a regular pattern of each time one missing pin.
A preferred monocast heat exchanger comprises a manifold for the supply of water to the plurality of parallel water channels. The manifold for the supply of water is integrally cast with the monocast heat exchanger.
A preferred monocast heat exchanger comprises a manifold for the exit of water from the plurality of parallel water channels out of the monocast heat exchanger. The manifold for the exit of water is integrally cast with the monocast heat exchanger.
In a preferred monocast heat exchanger, each of the plurality of water channels comprises reinforcing pins extending between the first cast wall and the second cast wall.
Preferably, the water channels comprise ribs protruding from the first cast walls into the water channel. The water channels comprise ribs protruding from the second cast walls into the water channel. The ribs are parallel with the intermediate walls.
A preferred monocast heat exchanger comprises at both lateral sides of the heat exchanger a side water channel. The two side water channels are parallel with the plurality of water channels. Each of the two side water channels is provided in between a third cast wall and a fourth cast wall. In between each third cast wall and each fourth cast wall intermediate walls are provided connecting the third cast wall with the fourth cast wall, thereby creating a meandering water channel between the third cast wall and the fourth cast wall. Each of the two third cast walls are in heat exchanger contact with one of the flue gas channels and are provided with protruding pins extending into a flue gas channel. Each of the two fourth cast walls provides a lateral side of the monocast heat exchanger. The fourth cast walls are not in
-4heat exchange relationship with flue gas channels. Preferably, the pin arrangement on the third cast walls is the same as on the first cast walls and as on the second cast walls.
In a preferred monocast heat exchanger the combustion chamber has the shape of a beam with a triangular cross section.
Preferably, the combustion chamber has the shape of a beam with a triangular cross section. The combustion chamber is delimited by three sides, by a cast front end, and by a cast back end. The first side comprises, and preferably consists out of, a cast wall. The second side comprises, and preferably consists out of, a cast wall with an opening for mounting a gas burner. Preferably, the gas burner is a fully premixed surface stabilized gas burner. The third side is open for flue gas generated in the combustion channel to flow into the plurality of flue gas channels.
The second aspect of the invention is a heat cell comprising a monocast heat exchanger as in any embodiment of the first aspect of the invention; and a surface stabilized fully premixed gas burner provided in the combustion chamber for the generation of flue gas.
In a preferred heat cell, the surface stabilized fully premixed gas burner has a beam shape with a triangular cross section. The burner comprises three sides, a closed front end and a closed back end. The first side and the second side of the burner comprise a perforated plate through which premix gas flows before it is combusted. Preferably, the perforated plate is covered by a woven, knitted or braided fabric comprising or consisting out of stainless steel fibers, preferably out of yarns comprising or consisting in their cross section a plurality of stainless steel fibers. The third side of the burner is open for the introduction of premix gas to be combusted after it has flown through the perforations of the perforated plate of the first side or of the second side of the burner.
Brief Description of Figures in the Drawings
Figure 1 shows an example of a monocast heat exchanger according to the invention. Figures 2, 3 and 4 show cross sections of the monocast heat exchanger of figure 1. Figure 5 shows a burner as can be used in a heat cell according to the second aspect of the invention.
Mode(s) for Carrying Out the Invention
Figure 1 shows an example of a monocast heat exchanger according to the invention. Figures 2, 3 and 4 show cross sections of the monocast heat exchanger of figure 1. Figure 2 shows a section along the length of the heat exchanger. Figure 3 shows a cross section through one of the parallel water channels. Figure 4 shows a cross section through one of the parallel flue gas channels of the monocast heat exchanger. Figures 3 and 4 show cross
-5section of a monocast heat exchanger in which a burner 170 - as in figure 5 - is provided in the combustion chamber 102.
The monocast heat exchanger 100 comprises a combustion chamber 102 for the generation of flue gas and a plurality of flue gas channels 104, parallel to each other, extending from the combustion chamber for flue gas to flow from the combustion chamber.
The combustion chamber has the shape of a beam with a triangular cross section. The combustion chamber is delimited by three sides, by a cast front end 106, and by a cast back end 108. The first side 110 comprises a cast wall. The second side comprises a cast wall 112 with an opening 114 for mounting a gas burner. The third side is open for flue gas generated in the combustion channel to flow into the plurality of flue gas channels.
The monocast heat exchanger comprises a manifold 116 for the supply of water to the plurality of parallel water channels. The manifold for supply of water is integrally cast with the monocast heat exchanger.
The monocast heat exchanger comprises a manifold 118 for the exit of water from the plurality of parallel water channels out of the monocast heat exchanger. The manifold for the exit of water is integrally cast with the monocast heat exchanger.
The monocast heat exchanger comprises a plurality of water channels 120, parallel to each other, for the flow of water to be heated by heat exchange from the flue gas flowing through the flue gas channels. Each of the water channels is provided in between a first cast wall 122 and a second cast wall 124. In between each first cast wall and each second cast wall intermediate walls 126 are provided connecting the first cast wall with the second cast wall, thereby creating a meandering water channel between the first cast wall and the second cast wall. Each of the first cast walls and each of the second cast walls are in heat exchange contact each with one of the flue gas channels. Each of the plurality of water channels comprise reinforcing pins 128 extending between the first cast wall and the second cast wall. The water channels comprise ribs 130 protruding from the first cast walls into the water channel. The water channels comprise ribs 130 protruding from the second cast walls into the water channel. The ribs are parallel with the intermediate walls.
The first cast walls and the second cast walls each comprise a first section 132 with pins protruding into the flue gas channel, a second section 134 with pins protruding into the flue gas channel and a third section 136 with pins protruding into the flue gas channel. The second section is provided in flue gas flow direction downstream from the first section. The third section is provided in flue gas flow direction downstream from the second section. In the first section each pin 138 protruding from the first wall is aligned with a pin from the second wall such that a gap is provided between the tip of the pin protruding from the first wall and the tip of the pin with which it is aligned and which protrudes from the second wall. The pins on the first wall and the pins on the second wall are arranged in rows of pins. The
-6rows are perpendicular to the flue gas channel. The pins in the rows in flue gas flow direction more downstream are longer than the pins in the rows in flue gas flow direction more upstream. Each row of pins has a gap length. The gap length decreases in flue gas downstream direction. The difference in gap length is larger between each row of pins and its in flue gas flow direction previous row of pins than between each row of pins and its in flue gas flow direction next row of pins.
The second section comprises first pins 140 protruding from the first cast wall, second pins 142 protruding from the second cast wall, third pins 144 protruding from the first cast wall and fourth pins 146 protruding from the second cast wall. In the example, the first pins, the second pins, the third pins and the fourth pins all have the same diameter. The first pins and the fourth pins have the same length. The second pins and the third pins have the same length. The first pins are longer than the second pins. Each first pin is aligned with a second pin, such that a gap is provided between the tip of the first pin and the tip of the second pin with which it is aligned. Each third pin is aligned with a fourth pin, such that a gap is present between the tip of the third pin and the tip of the fourth pin with which it is aligned. First pins and third pins alternate on the first cast wall in the second section. Second pins and fourth pins alternate on the second cast wall in the second section.
In the exemplary monocast heat exchanger, the pins in the first section have a larger diameter than the pins in the second section; and the pins in the second section have the same diameter as the pins in the third section.
In the third section fifth pins 148 are provided extending over the full distance between the first cast wall and the second cast wall. Fifth pins protrude from the first cast wall and from the second cast wall.
The pins in the first section, in the second section and in the third section are provided on the first walls and on the second walls according to regular patterns. On the first wall, in the first section, in the second section and in the third section, the regular patterns are interrupted in a regular way by missing pins. The regular way of missing pins is provided by a regular pattern of each time one missing pin 150. The regular patterns of pins on the second wall is not interrupted by missing pins.
The exemplary monocast heat exchanger comprises at both lateral sides of the heat exchanger a side water channel 152. The two side water channels are parallel with the plurality of water channels. Each of the two side water channels is provided in between a third cast wall 154 and a fourth cast wall 156. In between each third cast wall and each fourth cast wall intermediate walls 158 are provided connecting the third cast wall with the fourth cast wall, thereby creating a meandering water channel between the third cast wall and the fourth cast wall. Each of the two third cast walls are in heat exchanger contact with one of the flue gas channels and are provided with protruding pins extending into a flue gas channel. Each of
- 7the two fourth cast walls provides a lateral side of the monocast heat exchanger. The fourth cast walls are not in heat exchange relationship with flue gas channels. The pin arrangement on the third cast walls is the same as on the first cast walls and as on the second cast walls. The monocast heat exchanger is cast out of an aluminium alloy in one single casting operation.
By addition of a surface stabilized fully premixed gas burner in the combustion chamber of the monocast heat exchanger for the generation of flue gas, a heat cell according to the second aspect of the invention is obtained.
Figure 5 shows a burner 170 as can be used in a heat cell according to the second aspect of the invention; as shown in figures 3 and 4. The surface stabilized fully premixed gas burner has a beam shape with a triangular cross section. The burner comprises three sides, a closed front end and a closed back end. The first side and the second side of the burner comprise a perforated plate 180 through which premix gas flows before it is combusted. The perforated plate is covered by a knitted fabric 182 consisting out of yarns comprising in their cross section a plurality of stainless steel fibers. The gas is combusted on the surface of the fabric after the premix gas has flown through the fabric. The third side of the burner is open for the introduction of premix gas to be combusted after it has flown through the perforations of the perforated plate of the first side or of the second side of the burner and through the fabric covering the perforated plate.

权利要求:
Claims (15)
[1]
CONCLUSIONS
1. Heat exchanger cast in one piece, containing,
- a combustion chamber for the production of flue gas,
- a plurality of flue gas channels, parallel to each other, extending from the combustion chamber for flow of flue gas from the combustion chamber,
- a plurality of water channels, parallel to each other, for the flow and heating of water through transfer of heat from the flue gas that flows through the flue gas channels; wherein each of the water channels is between a first molded wall and a second molded wall, with intermediate walls between each first molded wall and each second molded wall connecting the first molded wall to the second molded wall, thereby forming a meandering water channel is cast between the first wall and the second wall;
wherein each of the first cast walls and each of the second cast walls are in heat exchange contact with one of the flue gas channels;
wherein the first molded walls and the second molded walls each include a first section provided with pins extending into the flue gas channel, a second section provided with pins extending into the flue gas channel, and a third section provided with pins extending into the flue gas channel ;
wherein the second section is downstream of the first section in the flue gas direction; wherein the third section is downstream of the second section in the flue gas direction; wherein in the first section each pin extending from the first cast wall is aligned with a pin extending from the second cast wall so that there is an opening between the tip of the pin extending from the first cast wall and the tip of the inline pin extending from the second molded wall;
and wherein in the first section the length of each pin extending from the first cast wall is equal to the length of the aligned pin extending from the second cast wall;
the second section including first pins extending from the first cast wall, second pins extending from the second cast wall, third pins extending from the first cast wall and fourth pins extending from the second cast wall;
the first pins and the fourth pins having the same length, the second pins and the third pins having the same length, the first pins being longer than the second pins, each first pin being associated with a second pin, so that a a gap is provided between the tip of the first pin and the tip of the second pin with which the first pin is aligned;
wherein each third pin is aligned with a fourth pin, such that an opening is provided between the tip of the third pin and the tip of the fourth pin with which the third pin is aligned;
wherein fifth pins are provided in the third section, the fifth pins extending the full distance between the first molded wall and the second molded wall; and wherein the fifth pins extend from the first molded wall and from the second molded wall.
[2]
A heat exchanger cast in one piece as in claim 1, wherein in the second section alternate first pins and third pins on the first cast wall; and wherein in the second section, second pins and fourth pins alternate on the second cast wall.
[3]
A heat exchanger cast in one piece as in any of the preceding claims, wherein in the first section the pins on the first wall and the pins on the second wall are arranged in pin rows, the rows perpendicular to the flue gas duct;
wherein the pins in the rows in the flue gas direction are longer downstream than the pins in the rows more upstream.
[4]
A heat exchanger molded in one piece as in any of the preceding claims, wherein the first section includes rows of pins; wherein the rows of pins are perpendicular to the flue gas channel;
wherein each row of pins has a length of the opening, the length of the opening being the distance between tips of the pins extending from the first wall and the tips extending from the second wall;
wherein the length of the opening decreases in the flue gas downstream direction;
wherein the difference in length of the aperture is greater between each row of pins and its row of pins in the flue gas direction than between each row of pins and its row of pins in the flue gas direction.
[5]
A heat exchanger cast in one piece as in any of the preceding claims, wherein pins in the first section, in the second section and in the third section are placed on the first cast wall and on the second cast wall in regular patterns ; wherein on the first wall, in the first section, in the second section and in the third section, the regular patterns are interrupted by missing pins.
[6]
A heat exchanger cast in one piece as in claim 5; wherein the regular patterns are interrupted in a regular manner by missing pins, the regular method of missing pins being obtained by one missing pin each time.
5
[7]
A heat exchanger molded in one piece as in any of the preceding claims, which includes a manifold for supplying water to the plurality of parallel water channels, the manifold for supplying water being integrally molded with the one-piece
10 molded heat exchanger.
[8]
A heat exchanger cast in one piece as in any of the preceding claims, which includes a manifold for draining water through the plurality of parallel water channels from the heat exchanger,
Wherein the water discharge manifold is integrally molded with the heat exchanger molded in one piece.
[9]
A heat exchanger cast in one piece as in any of the preceding claims, wherein each of the plurality of water channels includes reinforcement pins extending between the first wall and the second wall.
20
[10]
A heat exchanger cast in one piece as in any of the preceding claims, wherein the water channels include ribs extending into the water channel from the first cast wall;
and wherein the water channels contain ribs extending from the second cast wall into the
25 extending water channel, the ribs being parallel to the intermediate walls.
[11]
A heat exchanger cast in one piece as in any of the preceding claims, which includes a side water channel on both sides of the heat exchanger, the
30 side water channels are parallel to the plurality of water channels;
wherein each of the two side water channels is between a third molded wall and a fourth molded wall, with between each third molded wall and every fourth molded wall there are intermediate walls connecting the third molded wall to the fourth molded wall, a
Meandering water channel is created between the third cast wall and the fourth cast wall;
11 wherein each of the two third molded walls is in heat exchange contact with one of the flue gas channels and is provided with pins extending into the flue gas channel; each of the two fourth molded walls forming the side of the heat exchanger molded in one piece.
5
[12]
A heat exchanger cast in one piece as in any of the preceding claims, wherein the combustion chamber is in the form of a beam with a triangular cross-section.
[13]
13. A heat exchanger cast in one piece as in claim 12, wherein the combustion chamber is delimited by three sides, by a cast front and by a cast rear;
wherein the first side comprises a molded wall and is preferably constructed from it;
wherein the second side comprises a molded wall containing an opening for mounting a gas burner; and wherein the second side is preferably constructed from this cast wall;
Wherein the third side is open to allow flue gas produced in the combustion chamber to flow into the plurality of flue gas channels.
[14]
14. Heat cell, including
- a heat exchanger cast in one piece as in any of the preceding claims;
- a surface stabilized fully premixed gas burner, provided in the burner chamber for the production of flue gas.
[15]
A heat cell as in claim 14, which includes a heat exchanger cast in one piece as in claim 12 or 13;
wherein the surface stabilized fully premixed burner is in the form of a beam with triangular cross section;
wherein the burner has three sides, a closed front and a closed back;
wherein the first side and the second side of the burner contain a perforated plate through which premixed gas flows before being burned;
wherein the third side of the burner is open for introducing premixed gas to burn after it has flowed through the perforations of the perforated plate from the first side or from the second side.
1/4

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引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:

优先权:

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申请号 | 申请日 | 专利标题

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EP17179454|2017-07-04|

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