CN116265381B - Coil assembly, mixed gas preheating device and steam reforming hydrogen production furnace - Google Patents

Abstract

The present invention provides a coil assembly and a mixed gas preheating device and a steam reforming hydrogen production converter containing the same. The coil assembly has a mixed gas inlet, a mixed gas outlet, a first end and a second end opposite to the first end. The coil assembly includes a first coiled tube segment formed by winding a plurality of branch pipes, a second coiled tube segment and a hollow channel; the coil assembly also includes an inlet confluence pipe and an outlet confluence pipe. The inlet confluence pipe is provided with a mixed gas inlet, and the outlet confluence pipe is provided with a mixed gas outlet. The inlet confluence pipe is connected to the starting ends of a plurality of branch pipes in a divergent manner, and the outlet confluence pipe is connected to the terminal ends of a plurality of branch pipes in a confluence manner. The starting ends and terminal ends of the plurality of branch pipes are both adjacent to the first end. Among them, the second coiled tube segment is formed on the inner side of the first coiled tube segment, and the hollow channel is located on the inner side of the second coiled tube segment and runs through the first end to the second end. The coil assembly of the present invention can increase the heat exchange area, improve the heat exchange efficiency, and reduce the floor space.

Description

Coil assembly, mixed gas preheating device and steam reforming hydrogen production furnace

Technical Field

The present invention relates to the technical field of steam reforming hydrogen production, and in particular to a coil assembly, a mixed gas preheating device having the coil assembly, and a steam reforming hydrogen production converter comprising the mixed gas preheating device.

Background Art

The steam reforming hydrogen production conversion device includes a reformer and a mixed gas preheater. Generally, before the mixed gas flows into the reforming tube of the reformer, it needs to be preheated by the mixed gas preheater.

In the traditional steam reforming hydrogen production conversion device, the mixed gas preheater is set outside the reformer. The mixer preheater uses the heat of the high-temperature flue gas flowing out of the reformer to preheat the mixed gas. After flowing out of the reformer, the high-temperature flue gas needs to pass through a long flue before entering the mixed gas preheater, which not only occupies a large area, but also has a large amount of heat dissipation in the flue, resulting in a lot of heat loss.

Summary of the invention

The present invention provides a coil assembly, a mixed gas preheating device including the coil assembly and a steam reforming hydrogen production converter including the mixed gas preheating device, so as to reduce the floor space occupied by the steam reforming hydrogen production converter and reduce heat loss.

In a first aspect, the present invention provides a coil assembly for providing a fluid channel for the preheating process of a mixed gas in steam reforming hydrogen production. The coil assembly has a mixed gas inlet and a mixed gas outlet, and the coil assembly has a first end and a second end opposite to the first end. The coil assembly includes a first coiled tube segment formed by winding a plurality of branch pipes, a second coiled tube segment and a hollow passage. The coil assembly also includes an inlet confluence pipe and an outlet confluence pipe, the inlet confluence pipe is provided with a mixed gas inlet, and the outlet confluence pipe is provided with a mixed gas outlet. The inlet confluence pipe is connected to the starting ends of a plurality of branch pipes in a divergent manner, and the outlet confluence pipe is connected to the terminal ends of a plurality of branch pipes in a confluence manner. The starting ends and terminal ends of the plurality of branch pipes are both adjacent to the first end of the coil assembly. Among them, the first coiled tube segment is formed by a plurality of branch pipes spirally extending from the inlet confluence pipe to the second end, and the second coiled tube segment is formed by a plurality of branch pipes spirally extending from the second end to the outlet confluence pipe on the inner side of the first coiled tube segment. The hollow passage is located inside the second coiled tube segment and extends from the first end to the second end.

In some embodiments, the inlet merging pipe and the outlet merging pipe are both annular, and a plurality of branch pipes are connected to the inlet merging pipe and the outlet merging pipe at equal intervals in the circumferential direction.

Preferably, the plurality of branch pipes are configured as six branch pipes.

In a second aspect, the present invention provides a mixed gas preheating device for preheating a mixed gas through flue gas in steam reforming hydrogen production, which includes an outer smoke hood, the aforementioned coil assembly, and an intermediate chimney. The outer smoke hood has a bottom and a top, and is provided with a smoke inlet and a smoke outlet. The coil assembly is arranged inside the outer smoke hood, the first end of the coil assembly is adjacent to the bottom of the outer smoke hood, and the second end of the coil assembly is adjacent to the top of the outer smoke hood. The intermediate chimney is arranged between the first coil tube group segment and the second coil tube group segment, and the intermediate chimney extends from the first end to the second end of the coil assembly, so that the flow direction of the smoke is limited to first flowing from the smoke inlet to the top of the outer smoke hood and then from the top of the outer smoke hood to the smoke outlet; wherein, the smoke inlet and the smoke outlet are both arranged at a position adjacent to the first end of the coil assembly.

In some embodiments, the mixed gas preheating device also includes an inner chimney, which is arranged in the hollow channel of the coil assembly and extends from the first end to the second end of the coil assembly, so that the flue gas flow path from the top of the outer smoke hood to the smoke outlet is limited between the middle chimney and the inner chimney.

Preferably, the side wall of the outer smoke hood is circumferentially evenly spaced with a plurality of smoke inlets corresponding to the number of the plurality of branch pipes, and each smoke inlet is circumferentially staggered with the starting end of each branch pipe; the smoke outlet is arranged at the bottom of the outer smoke hood.

In some embodiments, the mixed gas preheating device further comprises a mixed gas inlet connection end and a mixed gas outlet connection end. The mixed gas inlet connection end is connected to the mixed gas inlet of the coil assembly; and the mixed gas outlet connection end is connected to the mixed gas outlet of the coil assembly. Wherein, the mixed gas inlet connection end and the mixed gas outlet connection end are both arranged at the bottom of the outer smoke hood and extend to the outside of the outer smoke hood.

In some embodiments, a tube bundle fixing bracket is further provided in the outer smoke hood, and the tube bundle fixing bracket fixes the coil assembly to the middle smoke pipe.

Preferably, the outer smoke hood is provided with a layer of heat insulation material.

In a third aspect, the present invention provides a steam reforming hydrogen production converter, which includes the aforementioned mixed gas preheating device, wherein the main body of the mixed gas preheating device is arranged below the interior of the furnace body of the converter, and the smoke inlet is located inside the furnace body; the mixed gas inlet connection end and the mixed gas outlet connection end both extend to the outside of the furnace body; the smoke outlet is constructed to be suitable for connecting with the smoke exhaust chimney outside the bottom of the furnace body.

The features and advantages of the present invention include:

The coil assembly provided by the present invention, because the first coiled tube segment and the second coiled tube segment are formed by extending and rotating a plurality of branch tubes, and the second coiled tube segment is located on the inner side of the first coiled tube segment, when the height (tube spacing of the coil assembly) and width (center circle diameter of the coil assembly) of the coil assembly are constant, the path of the mixed gas flow channel can be extended, the heat exchange area can be increased, and the heat exchange efficiency can be improved. In other words, when the mixed gas is preheated to the same temperature, the height and width of the coil assembly can be greatly reduced. The volume of the mixed gas heat exchange device using the coil assembly can be placed inside the existing converter, thereby reducing the floor space and heat loss.

The mixed gas preheating device provided by the present invention has a flue gas flow and a mixed gas flow that first flows from bottom to top and then from top to bottom. The two flow in parallel for heat exchange, thereby avoiding cracking and carbonization of carbon-containing raw materials (such as natural gas) in the mixed gas.

The steam reforming hydrogen production converter provided by the present invention integrates the mixed gas preheating device into the steam reforming hydrogen production converter, effectively utilizing the internal space of the furnace, which can reduce the floor space of the steam reforming hydrogen production converter, and the flue gas directly enters the mixed gas preheating device from the inside of the furnace body, which can reduce heat loss. By providing a heat insulation material layer on the outer surface of the mixed gas preheating device, the heat of the flue gas cannot be conducted into the mixed gas preheating device through the main body of the mixed gas preheating device, which can avoid affecting the heat transfer efficiency of the flue gas in the furnace to the conversion tube. The mixed gas preheating device can be detachably installed and fixed from the bottom of the converter, that is, a space for detachably withdrawing the mixed gas preheating device is reserved at the bottom of the converter, so that the mixed gas preheating device can be repaired or replaced without affecting the entire furnace body.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

FIG1 is a schematic structural diagram of a steam reforming hydrogen production converter according to the present invention;

FIG2A is a schematic structural diagram of an embodiment of a mixed gas preheating device of the present invention;

FIG2B is a schematic diagram of the structure after cutting along the A-A direction in FIG2A ;

FIG3A is a schematic structural diagram of an embodiment of a coil assembly of the present invention;

FIG. 3B is a schematic diagram of the three-dimensional structure of one branch pipe of the coil assembly.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

With reference to FIG1 , the present invention discloses a steam reforming hydrogen production converter 30, such as a natural gas reforming hydrogen production converter, which causes a raw gas mixture (a mixture of natural gas and water vapor) to undergo a reforming conversion reaction to generate a reformed gas (a mixture of methane, hydrogen, CO, CO2, and H2O). A main burner 33 and a reforming tube 34 are provided in the reforming furnace 30. The top of the reforming tube 34 extends above the top of the furnace body of the reforming furnace 30, and the top of the reforming tube 34 is provided with a mixed gas inlet port; the bottom of the reforming tube 34 extends to below the bottom of the furnace body of the reforming furnace 30, and the bottom of the reforming tube 34 is provided with a reformed gas outlet port. The reforming tube 34 is provided with a catalyst required for the reforming reaction, and the high-temperature flue gas generated by the combustion of the burner 33 provides the required heat for the reforming conversion reaction in the reforming tube 34.

According to some embodiments of the present disclosure, the reformer 30 includes a mixed gas preheating device 20, the main body of which is disposed below the furnace body of the reformer 30. The mixed gas preheating device 20 uses the high-temperature flue gas inside the furnace body to preheat the raw gas mixed gas from 200 to 300° C. to 500 to 600° C. The mixed gas preheated by the mixed gas preheating device 20 is guided to the reforming tube 34 to undergo a reforming reaction.

According to a specific embodiment of the present disclosure, referring to FIG. 1 and FIG. 2A , the mixed gas preheating device 20 has a top and a bottom, and its bottom is configured as a part of the bottom of the reformer 30. The mixed gas preheating device 20 has a smoke inlet 21a and a smoke outlet 21b, wherein the smoke inlet 21a is located inside the furnace body and close to the bottom of the mixed gas preheating device 20, and the smoke outlet 21b is located at the bottom of the mixed gas preheating device 20 and the smoke outlet 21b is connected to the smoke exhaust 32 outside the furnace body. The bottom of the mixed gas preheating device 20 is provided with a mixed gas inlet connection end 25 and a mixed gas outlet connection end 26, and the mixed gas inlet connection end 25 and the mixed gas outlet connection end 26 both extend to the outside of the furnace body of the reformer 30. The raw mixed gas at 200-300°C flows into the mixed gas preheating device 20 from the mixed gas inlet connection end 25. In the mixed gas preheating device 20, the raw mixed gas absorbs the heat of the flue gas, and then the raw mixed gas at 500-600°C flows out of the mixed gas preheating device 20 from the mixed gas outlet connection end 26. Preferably, a heat insulating material layer 21c is provided on the outer surface of the mixed gas preheating device 20, for example, a heat insulating layer of cast ceramic fiber plastic or other amorphous refractory heat insulating material.

The present invention effectively utilizes the space inside the furnace by arranging the mixed gas preheating device inside the furnace of the converter. If the mixed gas preheating device is arranged outside the furnace, the flue gas flowing out of the converter needs to be guided to the mixed gas preheating device through the smoke exhaust chimney. Since there is a distance between the converter and the mixed gas preheating device, and the smoke exhaust chimney is arranged outside the converter, the flue gas will lose a lot of heat in the process of flowing through the smoke exhaust chimney. Therefore, compared with arranging the mixed gas preheating device outside the furnace, the present invention can not only reduce the footprint of the entire device, but also reduce the heat loss of the system. In addition, by arranging a heat-insulating material layer on the outer surface of the mixed gas preheating device, the heat of the flue gas cannot be conducted to the mixed gas preheating device through the outer shell of the mixed gas preheating device, which can avoid affecting the heat transfer efficiency of the flue gas in the furnace to the converter tube. In short, the present invention achieves the beneficial effects of compact arrangement of the converter and the mixed gas preheating device and energy saving.

According to some specific embodiments of the present invention, the mixed gas preheating device can be detachably installed and fixed from the bottom of the converter, that is, a space for detachably withdrawing the mixed gas preheating device is reserved at the bottom of the converter, so that the mixed gas preheating device can be repaired or replaced without affecting the entire furnace body.

2A , in some embodiments, the mixed gas preheating device 20 includes an outer smoke hood 21, an intermediate chimney 22, and a coil assembly 10. The intermediate chimney 22 and the coil assembly 10 are both arranged inside the outer smoke hood 21. The outer smoke hood 21 has a top and a bottom, which can serve as the top and the bottom of the mixed gas preheating device 20. The heat insulating material layer 21c on the outer surface of the mixed gas preheating device 20 can be arranged on the outer smoke hood 21. A smoke inlet 21a can be arranged at the lower part of the side wall of the outer smoke hood 21, and a smoke outlet 21b can be arranged at the bottom of the outer smoke hood 21.

The coil assembly 10 is used to provide a fluid passage for the mixed gas. The coil assembly 10 is connected to the mixed gas inlet connection end 25 in the upstream direction and is connected to the mixed gas outlet connection end 26 in the downstream direction. The coil assembly 10 has a first end 10a and a second end 10b opposite to the first end. The first end 10a is adjacent to the bottom of the outer smoke cover 21, and the second end 10b is adjacent to the top of the outer smoke cover 21. The coil assembly 10 has a mixed gas upward flow passage (upward section) from the bottom to the top of the outer smoke cover 21 and a mixed gas downward flow passage (downward section) from the top to the bottom of the outer smoke cover 21.

2A and 2B, the middle chimney 22 is disposed between the mixed gas upward flow passage and the mixed gas downward flow passage of the coil assembly 10, and extends from the bottom to the top of the outer smoke cover 21. The arrangement of the middle chimney 22 divides the flow passage of the flue gas flow 50 in the mixed gas preheating device 20 into an outer flow passage 51 and an inner flow passage 52, wherein the outer flow passage 51 is located between the outer smoke cover 21 and the middle chimney 22, and the inner flow passage 52 is located inside the middle chimney 22. The flow direction of the flue gas is defined as first flowing from the smoke inlet 21a along the outer flow passage 51 to the top of the outer smoke cover 21 (upward section) and then flowing from the top of the outer smoke cover 21 to the smoke outlet 21b (downward section) along the inner flow passage 52.

Continuing to refer to FIG. 2A and FIG. 2B , in some embodiments, the middle portion of the coil assembly 10 has a hollow passage 15 that runs through the first end 10a to the second end 10b, and an inner chimney 24 is provided in the hollow passage 15. The inner chimney 24 extends from the first end 10a to the second end 10b of the coil assembly 10. The mixed gas preheating device 20 provided with the inner chimney 24 has an inner flow channel 52 of the flue gas flow 50 located between the inner chimney 24 and the middle chimney 22. The provision of the inner chimney 24 allows the flue gas heat in the inner flow channel 52 (downstream section) to be concentrated around the mixed gas downstream flow channel of the coil assembly 10, thereby improving the heat exchange effect between the flue gas in the downstream section and the mixed gas in the downstream section.

3A and 3B , some specific embodiments of the coil assembly 10 of the present invention are described in detail below.

The coil assembly 10 of the present invention is used to provide a fluid channel for the preheating process of the mixed gas in steam reforming hydrogen production, and has a mixed gas inlet 111 and a mixed gas outlet 121. The coil assembly 10 has a first end 10a and a second end 10b opposite to the first end 10a, the first end 10a is suitable for being arranged at a position close to the bottom of the aforementioned outer smoke hood 21, and the second end 10b is suitable for being arranged at a position close to the top of the aforementioned outer smoke hood 21.

Specifically, the coil assembly 10 includes an air inlet manifold 11 and an air outlet manifold 12, a mixed gas inlet 111 is provided at the air inlet manifold 11, and a mixed gas outlet 121 is provided at the air outlet manifold 12. The air inlet manifold 11 is connected to the starting ends 14a of a plurality of branch pipes 14 in a divergent manner, and the air outlet manifold 12 is connected to the terminal ends 14b of a plurality of branch pipes 14 in a confluent manner. The starting ends 14a and the terminal ends 14b of the plurality of branch pipes 14 are both adjacent to the first end 10a of the coil assembly 10, that is, adjacent to the bottom of the aforementioned outer smoke cover 21.

In particular, referring to FIG3B , each branch pipe 14 is first spirally wound upward from the starting end 14a and then spirally wound downward to the terminal end 14b, the pipe section spirally wound upward forms the first coiled pipe section, and the pipe section spirally wound downward forms the second coiled pipe section. The first coiled pipe section is in fluid communication with the second coiled pipe section, the second coiled pipe section is located on the inner side of the first coiled pipe section, and a hollow passage is formed on the inner side of the second coiled pipe section. Referring to FIG3A , the coil assembly 10 includes a first coiled pipe section 13a and a second coiled pipe section 13b formed by a plurality of branch pipes being wound in parallel as a whole. In which, the overall parallel winding means that a plurality of branch pipes 14 are arranged side by side and rotate in parallel around the same axis with the same radius. Preferably, the axis of the first coiled pipe section 13a coincides with the axis of the second coiled pipe section 13b. The first coiled pipe segment 13a is formed by a plurality of branch pipes 14 spirally extending from the inlet converging pipe 11 to the second end 10b, and the second coiled pipe segment 13b is formed by a plurality of branch pipes 14 spirally extending from the second end 10b to the outlet converging pipe 12 and is formed on the inner side of the first coiled pipe segment 13a. The first coiled pipe segment 13a provides an upward flow path for the mixed gas from the bottom to the top of the outer smoke cover 21, and the second coiled pipe segment 13b provides a downward flow path for the mixed gas from the top to the bottom of the outer smoke cover 21.

In some embodiments, a hollow passage 15 is formed between the first end 10a and the second end 10b on the inner side of the second coiled tube segment 13b. In some embodiments, there is a longitudinal distance between the intake manifold 11 and the outlet manifold 12, so that in the aforementioned mixed gas preheating device 20, the outlet manifold 12 is located below the intake manifold 11.

In a preferred embodiment, the inlet confluence pipe 11 and the outlet confluence pipe 12 are both annular, and a plurality of branch pipes 14 are connected to the inlet confluence pipe 11 and the outlet confluence pipe 12 at equal intervals in the circumferential direction. In general, a suitable number of smoke inlets 21a and branch pipes 14 can be set according to the hydrogen production scale of the hydrogen production converter, for example, 2 to 8 can be set respectively. In particular, referring to FIG. 2B, the coil assembly 10 is provided with six branch pipes 14. Correspondingly, in some preferred embodiments, referring to FIG. 2B, in the mixed gas preheating device 20, six smoke inlets 21a corresponding to the number of branch pipes 14 in the coil assembly 10 are arranged at equal intervals in the circumferential direction below the side wall of the outer smoke hood 21, and each smoke inlet 21a is staggered with the starting end 14a of each branch pipe 14 in the circumferential position. Further, referring to FIG. 2A, a plurality of smoke inlets 21a are arranged above the inlet confluence pipe 11 and the outlet confluence pipe 12 in the longitudinal direction.

According to the coil assembly 10 of the present invention, referring to FIG. 3A , the plurality of branch pipes 14 may be arranged in parallel as a whole, spirally extending from the inlet manifold 11 to the second end 10b in a clockwise direction to form a first coiled pipe segment 13a, and then continue to be arranged in parallel as a whole, spirally extending from the second end 10b in a clockwise direction to the outlet manifold 12 to form a second coiled pipe segment 13b. Alternatively, according to the coil assembly 10 of the present invention, the plurality of branch pipes 14 may also be arranged in parallel as a whole, spirally extending from the inlet manifold 11 to the second end 10b in a counterclockwise direction to form a first coiled pipe segment 13a, and then continue to be arranged in parallel as a whole, spirally extending from the second end 10b in a counterclockwise direction to the outlet manifold 12 to form a second coiled pipe segment 13b.

The coil assembly 10 is used to provide an upward mixed gas fluid channel (first coiled tube segment 13a) and a downward mixed gas fluid channel (second coiled tube segment 13b) for the preheating process of the mixed gas in steam reforming hydrogen production. Since the first coiled tube segment 13a and the second coiled tube segment 13b are formed by a plurality of branch pipes 14 that are spirally arranged in parallel as a whole, and the second coiled tube segment 13b is located on the inner side of the first coiled tube segment 13, when the height (tube spacing of the coil assembly 10) and width (center circle diameter of the coil assembly) of the coil assembly 10 are constant, the path of the mixed gas flow channel can be extended, the heat exchange area can be increased, and the heat exchange efficiency can be improved. In other words, when the mixed gas is preheated to the same temperature, the height and width of the coil assembly 10 can be greatly reduced. This allows the volume of the mixed gas heat exchange device using the coil assembly to be sufficient to be placed inside the existing reformer.

Alternatively, in other embodiments, the plurality of branch pipes 14 are independently rotated upward around different axes from the inlet converging pipe 11 to the second end 10b, and then independently rotated downward around different axes from the second end 10b to the outlet converging pipe 12, wherein the rotation axis of the first coiled pipe section of each branch pipe 14 does not coincide with the rotation axis of the second coiled pipe section. The first coiled pipe sections of the plurality of branch pipes form a first coiled pipe group section 13a, and the second coiled pipe sections of the plurality of branch pipes form a second coiled pipe group section 13b.

It should be noted that although the present invention uses mixed gas as the preheating medium in the coil assembly, the mixed gas medium itself should not constitute a limitation on the protection scope of the structural structure of the coil assembly. The coil assembly of the present invention is used to provide a fluid channel for other fluid media that need to increase the temperature and should be equivalently regarded as within the protection scope claimed by the present invention.

Continuing to refer to the mixed gas preheating device 20 shown in FIG. 2A , the smoke inlet 21a, the smoke outlet 21b, the mixed gas inlet 111, and the mixed gas outlet 121 are all arranged near the bottom of the device. The coil assembly 10 is arranged inside the outer smoke cover 21, and the coil assembly 10 includes an ascending first coiled tube segment 13a and a descending second coiled tube segment 13b. The first coiled tube segment 13a provides an ascending flow path for the mixed gas that spirals upward, and the second coiled tube segment 13b provides a descending flow path for the mixed gas that spirals downward. The intermediate chimney 22 is arranged between the first coiled tube segment 13a and the second coiled tube segment 13b, and the intermediate chimney 22 extends from the first end 10a to the second end 10b of the coil assembly 10. In the transverse (radial) direction, there is a spacing d1 between the outer smoke cover 21 and the first coiled tube segment 13a, a spacing d2 between the intermediate chimney 22 and the first coiled tube segment 13a, and a spacing d3 between the intermediate chimney 22 and the second coiled tube segment 13b. By setting a suitable spacing value, the flow rate of the flue gas is in the range of 8 to 25 m/s. By setting a flue gas guide tube (such as the intermediate chimney 22) in the mixed gas preheating device 20, it is possible to achieve that the flue gas flow 50 and the mixed gas flow 40 first flow from bottom to top and then from top to bottom, thereby achieving the effect of making the two flow in parallel for heat exchange, and avoiding cracking and carbonization of carbon-containing raw materials (such as natural gas) in the mixed gas.

In some preferred embodiments, an inner chimney 24 is further provided in the hollow passage 15 inside the second coiled tube segment 13b of the coil assembly 10, and the inner chimney 24 extends from the first end 10a to the second end 10b of the coil assembly 10. In the transverse (radial) direction, there is a spacing d4 between the second coiled tube segment 13b and the inner chimney 24. When the radial dimension of the hollow passage 15 is large, by providing the inner chimney 24, the heat of the flue gas in the downward heat exchange process can be gathered around the second coiled tube segment 13b, thereby improving the heat exchange effect of the downward section.

Furthermore, a first rib plate 22a is provided between the top of the inner chimney 24 and the top of the outer chimney cover 21, and a second rib plate 22b is provided between the bottom of the inner chimney 24 and the bottom of the outer chimney cover 21. The first rib plate and the second rib plate are provided to support the inner chimney, so that the center of gravity of the inner chimney in the outer chimney cover remains stable, and the entire mixed gas preheating device is more stable.

2A , the flow paths of the flue gas flow 50 and the mixed gas flow 40 in the co-current ascending stage and the co-current descending stage are respectively described below.

Parallel upward stage: the flue gas flow 50 enters the mixed gas preheating device 20 from the smoke inlet 21a below the outer smoke cover 21, and the flue gas flow 50 flows toward the top in the space (outer flow channel 51) defined between the middle smoke tube 22 and the outer smoke cover 21. Corresponding to this process, the mixed gas flow 40 enters the mixed gas preheating device 20 from the mixed gas inlet connection end 25 located at the bottom of the device, and the mixed gas flow 40 further flows from the mixed gas inlet 111 to the intake manifold 11, and then is divided by the intake manifold 11 into the starting end 14a of each branch pipe 14, and flows upward in a spiral direction toward the top along the first coiled pipe segment 13a formed by the coiling of each branch pipe 14.

Parallel downward flow stage: After the smoke flow 50 reaches the top, it turns and flows into the space (inner flow channel 52) defined by the inner side of the middle chimney 22, and continues to flow to the bottom, and finally converges and flows to the smoke outlet 21b at the bottom of the device. Correspondingly, after the mixed gas flow 40 reaches the second end 10b (near the top) of the coil assembly 10, it spirals downward along the second coiled tube segment 13b toward the first end 10a (near the bottom), and then merges from the terminal end 14b of each branch pipe 14 into the gas outlet converging pipe 12, and finally flows from the mixed gas outlet 121 of the gas outlet converging pipe 12 to the mixed gas outlet connection end 26 located at the bottom of the device.

Referring to FIG. 2A and FIG. 2B , in some preferred embodiments, the mixed gas preheating device 20 is further provided with a tube bundle fixing bracket 23, which fixes the coil assembly 10 at a suitable position in the outer smoke cover 21. Specifically, the tube bundle fixing bracket 23 fixes the coil assembly 10 to the middle chimney 22. The first coiled tube segment 13a and the second coiled tube segment 13b are respectively fixed to the middle chimney 22 by M tube bundle fixing brackets 23. Specifically, each tube bundle fixing bracket 23 includes N transverse brackets and 1 longitudinal bracket, the main body of the transverse bracket is V-shaped, the top of the longitudinal bracket has a bending portion, the N transverse brackets divide the coiled tube segment into N+1 layers, the V-shaped open end of the transverse bracket is fixed to the middle chimney 22, and the longitudinal bracket is inserted into the V-shaped closed end of each transverse bracket to connect the N transverse brackets into a whole. M and N can be integers greater than or equal to 2. In the embodiment shown in FIG. 2A and FIG. 2B , M=3, N=6.

The above-mentioned mixed gas preheating device realizes the parallel flow heat exchange between the flue gas and the mixed gas, the temperature of the flue gas gradually decreases from the upstream direction to the downstream direction, and the temperature of the mixed gas gradually increases from the upstream direction to the downstream direction. On the basis of ensuring that both the mixed gas and the flue gas meet the outlet temperature range requirements, the cracking and carbonization of the carbon-containing raw materials (such as natural gas) in the mixed gas can be avoided.

The above are only several embodiments of the present disclosure. Those skilled in the art may make various changes or modifications to the embodiments of the present disclosure based on the contents disclosed in the application documents without departing from the spirit and scope of the present disclosure.

Claims (9)

1. A mixed gas preheating device for preheating mixed gas through flue gas in steam reforming hydrogen production, characterized in that the mixed gas heat exchange device comprises:

the outer smoke cover is provided with a bottom and a top and is provided with a smoke inlet and a smoke outlet;

a coil assembly for providing a fluid path for a mixture preheating process in steam reforming hydrogen production, the coil assembly having a mixture inlet and a mixture outlet, the coil assembly having a first end and a second end opposite the first end, the coil assembly being disposed within the outer hood, the first end of the coil assembly being adjacent the bottom of the outer hood, the second end of the coil assembly being adjacent the top of the outer hood; the coil assembly includes:

A first coiled tube group section, a second coiled tube group section and a hollow passage formed by coiling a plurality of branch tubes; and

The gas inlet converging pipe is provided with the mixed gas inlet, and the gas outlet converging pipe is provided with the mixed gas outlet; the gas inlet converging pipe is connected with the initial ends of the plurality of branch pipes in a split flow mode, and the gas outlet converging pipe is connected with the final ends of the plurality of branch pipes in a converging mode; the start end and the end of the plurality of branch pipes are adjacent to the first end; wherein,

The first coil group section is formed by spirally coiling and extending the plurality of branch pipes from the air inlet converging pipe to the second end; the second coiled pipe section is spirally coiled and extended from the second end to the outlet converging pipe by the plurality of branch pipes and is formed on the inner side of the first coiled pipe section; the hollow passage is positioned inside the second coiled tubing set section and extends through the first end to the second end; and

An intermediate chimney disposed between the first coiled tube set section and the second coiled tube set section, the intermediate chimney extending in a direction from the first end to the second end of the coil assembly such that a flow direction of smoke is defined as flowing from the smoke inlet to the top of the outer smoke cage and then from the top of the outer smoke cage to the smoke outlet;

wherein, advance the mouth and the mouth all locates adjacent the position of the first end of coil pipe subassembly.

2. The mixture gas preheating device according to claim 1, wherein the inlet merging pipe and the outlet merging pipe are each annular, and the plurality of branch pipes are connected to the inlet merging pipe and the outlet merging pipe at equal intervals in the circumferential direction.

3. The mixture gas preheating apparatus according to claim 2, wherein the plurality of branch pipes is configured as 6 branch pipes.

4. A gas-mixture preheating device according to any one of claims 1 to 3, further comprising an inner chimney provided in the hollow passage of the coil assembly and extending in a direction from the first end to the second end of the coil assembly such that a flue gas flow path from the top of the outer hood to the outlet direction is defined between the intermediate chimney and the inner chimney.

5. The air-fuel mixture preheating device according to claim 4, wherein a plurality of smoke inlets corresponding to the plurality of branch pipes are circumferentially and equidistantly arranged on the side wall of the outer smoke cover, and each smoke inlet is staggered with the starting end of each branch pipe in the circumferential position; the smoke outlet is arranged at the bottom of the outer smoke cover.

6. The air-fuel mixture preheating device according to claim 5, characterized in that the air-fuel mixture preheating device further comprises:

the mixed gas inlet connection end is communicated with a mixed gas inlet of the coil assembly; and

The mixed gas outlet connection end is communicated with a mixed gas outlet of the coil pipe assembly;

The gas mixture inlet connecting end and the gas mixture outlet connecting end are respectively arranged at the bottom of the outer smoke cover and extend to the outer part of the outer smoke cover.

7. The gas-mixture preheating device according to claim 6, wherein a tube bundle fixing bracket is further provided in the outer hood, and the tube bundle fixing bracket fixes the coil assembly to the intermediate chimney.

8. The air-fuel mixture preheating device according to claim 7, wherein the outer smoke cover is provided with a heat insulating material layer.

9. A steam reforming hydrogen production reformer according to claim 1 to 8, wherein the reformer comprises a mixture preheating apparatus,

The main body of the mixed gas preheating device is arranged below the inside of the furnace body of the reformer, and the smoke inlet is arranged inside the furnace body;

The mixed gas inlet connection end and the mixed gas outlet connection end extend to the outside of the furnace body;

the smoke outlet is configured to be suitable for being communicated with a smoke exhaust barrel outside the bottom of the furnace body.