CN210366979U - Central tube type reformer - Google Patents

Abstract

The utility model provides a central tube type reformer, which comprises a radiation section and a convection section, wherein the bottom of the radiation section is communicated with the convection section, a central conversion tube and burners symmetrically positioned at the two sides of the central conversion tube are arranged at the top in the radiation section, the central conversion tube comprises an outer tube and an inner tube which are concentric, the lower end of the outer tube is closed, and a feed gas inlet is arranged after the upper end of the outer tube penetrates through the top of the radiation section; the lower end of the inner tube is higher than the lower end of the outer tube, and the upper end of the inner tube is bent to penetrate through the side wall of the outer tube outside the radiation section and then is provided with a converted gas outlet; the annular gap formed between the inner pipe and the outer pipe is filled with a catalyst. The utility model discloses a central reformer tube that the radiation section set up, the feed gas can be accomplished and preheat and the conversion, has cancelled the feed gas and has preheated the coil pipe, directly makes the inside materials such as the fire-resistant insulating layer that lay of reformer steel construction and reformer obtain practicing thrift, has effectively reduced investment cost, has improved the benefit and has practiced thrift the resource.

Description

Central tube type reformer

Technical Field

The utility model relates to a reborner technical field, concretely relates to central tubular reborner that natural gas hydrogen manufacturing used.

Background

On the hydrogen production process line, different raw materials and processes are adopted, and various options are available. The hydrogen production by natural gas has the advantages of short process flow, relatively low factory building investment, extremely high efficiency of converting methane, which is a main component of natural gas, into hydrogen, high productivity, low total energy consumption and the like, so that the hydrogen production route taking the natural gas as the raw material still has great competitiveness at present and in a period of time in the future. Among the many routes for hydrogen production, the steam reforming process using natural gas as the raw material has a great advantage in the hydrogen production industry, and the route for hydrogen production is shown in fig. 1.

The natural gas hydrogen production converter is a high-temperature device which takes natural gas, oil field gas, coke oven gas, refinery tail gas or light oil as raw materials under the conditions of high temperature and high pressure, and promotes the raw materials and water vapor to carry out conversion reaction in the converter tube under the action of a nickel-based catalyst in the converter tube to prepare the raw material gas (namely hydrogen) for synthesizing ammonia.

The technological process of preparing hydrogen by the natural gas steam conversion method is carried out under the pressure of 2.0-4.0 MPa (A) and the high temperature of 700-800 ℃, the operation conditions are harsh, the requirements on corresponding equipment materials are high, and the investment of the method generally accounts for 30% of the investment of non-shaped equipment of a synthetic ammonia plant.

The natural gas steam reaction is an endothermic reaction, and the required heat must be provided externally, usually by a burner (fuel gas is usually natural gas) arranged at the upper part or the lower part of the reformer, the burner emits heat, the heat energy is converted into radiation energy, the radiation energy is absorbed by the furnace tubes to meet the heat required by the reaction inside the reformer, and the process is usually carried out in a radiant chamber of the reformer. The radiation chamber is a part for performing radiation heat transfer through flame or high-temperature flue gas, the radiation chamber is a main place for heat exchange, 70-80% of the heat load of the whole natural gas steam reformer is borne by the radiation chamber, the radiation chamber is the most important part of the whole natural gas steam reformer, and the whole natural gas steam reforming reaction process is completed in the radiation chamber.

Because the reaction for preparing hydrogen by converting natural gas is a strong endothermic reaction, the temperature gradient of the catalyst bed layer is gradually reduced along the gas flow direction along with the enhancement of the reaction depth in the converter tube, but in order to perform the reaction in the whole furnace tube at a relatively stable temperature, the heat obtained by each section of the furnace tube is required to be inconsistent, and the heat obtained by the furnace tube is gradually increased along the reaction gas flow direction. The key problem of the design and operation of the radiant chamber of the reformer is to make the wall temperature of the furnace tube uniform from top to bottom, i.e. to reduce local carbon deposition and overheating caused by unbalanced reaction and to prolong the service life of the furnace tube. In a conventional natural gas steam reformer, a method of aligning the combustion direction of a burner with the flow direction of a raw material gas is adopted to solve this problem.

Generally, the raw gas entering the natural gas hydrogen production conversion device needs to be preheated to more than 200 ℃, and before entering the conversion section, the raw gas is preheated by a raw gas preheating coil of a convection section of the converter. In order to meet the requirement of preheating the raw gas, a lot of raw gas preheating coil materials are needed, the consumption of materials such as a corresponding reformer steel structure and a refractory heat-insulating layer laid inside the reformer is increased, and for a small natural gas reformer, the investment cost is too high, the benefit is low, and resources are wasted.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a reborner with central reformer, the feed gas accomplishes in this reformer and preheats and the conversion process to cancel the feed gas and preheat the coil pipe, directly make the inside materials such as refractory insulation layer that lay of reborner steel construction and reborner obtain practicing thrift, and finally reach the purpose that reduces investment cost, benefit and resources are saved.

In order to achieve the above purpose, the utility model provides a following technical scheme:

the utility model provides a central tube type reformer, which comprises a radiation section and a convection section, wherein the bottom of the radiation section is communicated with the convection section, a central conversion tube and burners symmetrically positioned at two sides of the central conversion tube are arranged at the top in the radiation section, the central conversion tube comprises an outer tube and an inner tube which are concentric, the lower end of the outer tube is closed, and the upper end of the outer tube penetrates through the top of the radiation section and is provided with a raw material gas inlet; the lower end of the inner tube is higher than the lower end of the outer tube, and the upper end of the inner tube is bent to penetrate through the side wall of the outer tube outside the radiation section and then is provided with a converted gas outlet; and a catalyst is filled in an annular gap formed between the inner pipe and the outer pipe.

Further, the catalyst is compacted up and down through a pressure plate and a tray respectively to form an annular catalyst bed layer.

Further, the lower end of the outer pipe is closed by an arc-shaped cover.

Furthermore, the convection section is equipped with a plurality of heat medium heat transfer units side by side from supreme down, and the draught fan is installed on the convection section top.

Furthermore, the heat medium heat exchange units are preheaters, and the total number of the heat medium heat exchange units is 3, and the heat medium heat exchange units are respectively a raw material preheater, an air preheater and a boiler feed water preheater.

Compared with the prior art, the utility model provides a central tube type reborner has following beneficial effect:

1. the feed gas can be preheated and converted through the central conversion pipe arranged in the radiation section, a feed gas preheating coil is omitted, materials such as a conversion furnace steel structure and a refractory heat-insulating layer laid inside the conversion furnace are directly saved, the investment cost is effectively reduced, the benefit is improved, and resources are saved;

2. through a plurality of heat medium heat transfer units that the convection current section set up, make the surplus heat of the high temperature flue gas that the combustor produced can obtain make full use of.

Drawings

FIG. 1 is a process route for hydrogen production by natural gas steam reforming;

fig. 2 is a schematic structural diagram of the present invention.

The reference numerals are explained below:

1: central reforming tube 11: outer tube

111: raw material gas inlet 12: inner pipe

121: a converted gas outlet 2: burner with a burner head

3: catalyst 4: pressure plate

5: the tray 6: heat medium heat exchange unit

7: and (4) an induced draft fan 8: and supporting the section steel.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments. It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict. For convenience of description, the words "upper", "lower", "left" and "right" in the following description are used only to indicate the correspondence between the upper, lower, left and right directions of the drawings themselves, and do not limit the structure.

As shown in fig. 2, the utility model provides a central tube type reformer, which comprises a radiation section and a convection section, the bottoms of which are communicated, a central reformer tube 1 and burners 2 symmetrically positioned at both sides of the central reformer tube 1 are arranged at the top in the radiation section, the central reformer tube 1 comprises an outer tube 11 and an inner tube 12 which are concentric, the lower end of the outer tube 11 is closed, and a feed gas inlet 111 is arranged at the upper end of the outer tube after penetrating through the top of the radiation section; the lower end of the inner tube 12 is higher than the lower end of the outer tube 11, and the upper end of the inner tube 12 is bent to penetrate through the side wall of the outer tube 11 outside the radiation section and then is provided with a reformed gas outlet 121; the annular gap formed between the inner tube 12 and the outer tube 11 is filled with the catalyst 3.

The catalyst 3 is compacted up and down through a pressure plate 4 and a tray 5 respectively to form a ring-shaped catalyst bed layer, and the raw material gas completes the preheating and conversion processes on the catalyst bed layer.

The lower end of the outer pipe 11 is sealed by an arc-shaped cover, and the arc-shaped cover has a guide effect on the raw material gas and can also reduce the resistance of the raw material gas in the flowing process.

The convection section is provided with a plurality of heat medium heat exchange units 6 side by side from bottom to top, and a draught fan 7 is installed at the top end of the convection section. In this embodiment, the heat medium heat exchange units 6 are preheaters, 3 in total, and are respectively a raw material preheater, an air preheater and a boiler feed water preheater. In this way, the residual heat of the high-temperature flue gas generated by the burner 2 can be fully utilized.

When the device works, the combustor 2 takes natural gas or mixed fuel gas of the tail gas of the natural gas mixing device as fuel to directly combust in a radiation section (namely a conversion section) to provide heat required by reaction for the reformer, and the flame length is less than 0.5m during operation; the heat released by combustion is converted into radiation energy, and the radiation energy is absorbed by the central conversion tube 1; raw gas enters the outer tube 11 from a raw gas inlet 111 at the upper end of the outer tube 11, passes through an annular gap formed between the outer tube 11 and the inner tube 12, completes the preheating and conversion processes under the action of a catalyst bed layer, and the converted gas which completes the hydrogen production by conversion leaves the converter through a converted gas outlet 121 at the upper end of the inner tube 12 and enters the subsequent working section; and the generated high-temperature flue gas enters the convection section under the action of the induced draft fan 7 and continuously provides heat for a plurality of heat medium heat exchange units arranged in the convection section. Through the central conversion pipe 1 arranged in the radiation section, the feed gas can be preheated and converted, a feed gas preheating coil is omitted, materials such as a conversion furnace steel structure and a refractory heat-insulating layer laid inside the conversion furnace are directly saved, the investment cost is effectively reduced, the benefit is improved, and resources are saved.

Therefore, in the embodiment, the steel structure of the whole reformer is made into a vertical structure by adopting Q235-B grade carbon steel, and the lower end of the steel structure is provided with the section steel support 8. The vertical walls and the furnace top of the radiation section and the convection section adopt refractory ceramic fiber linings, and the furnace bottom facing the combustor adopts refractory castable linings; the refractory castable has the characteristics of strong plasticity, suitability for various occasions with complicated shapes, simple construction and the like, and has higher smoke erosion resistance than refractory ceramic fibers.

The above only is the embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent processes of the present invention are used in the specification and the attached drawings, or directly or indirectly applied to other related technical fields, and the same principle is included in the protection scope of the present invention.

Claims (5)

1. A central tube type reformer comprises a radiation section and a convection section which are communicated with each other at the bottom, and is characterized in that a central reforming tube (1) and burners (2) symmetrically positioned at two sides of the central reforming tube (1) are installed at the top in the radiation section, the central reforming tube (1) comprises an outer tube (11) and an inner tube (12) which are concentric, the lower end of the outer tube (11) is closed, and a raw material gas inlet (111) is formed in the upper end of the outer tube after penetrating through the top of the radiation section; the lower end of the inner tube (12) is higher than the lower end of the outer tube (11), and the upper end of the inner tube (12) is bent to penetrate through the side wall of the outer tube (11) outside the radiation section and then is provided with a converted gas outlet (121); and a catalyst (3) is filled in an annular gap formed between the inner pipe (12) and the outer pipe (11).

2. The central tube reformer according to claim 1, characterized in that the catalyst (3) is compacted from top to bottom by means of a pressure plate (4) and a tray (5), respectively, to form a ring-shaped catalyst bed.

3. The central tube reformer according to claim 1, characterized in that the lower end of the outer tube (11) is closed with an arc-shaped cover.

4. The central tube reformer according to claim 1, characterized in that the convection section is provided with a plurality of heat medium heat exchange units (6) side by side from bottom to top, and an induced draft fan (7) is installed at the top end of the convection section.

5. The central tube reformer according to claim 4, characterized in that the heat medium heat exchange units (6) are preheaters, 3 in total, respectively a raw material preheater, an air preheater, a boiler feed water preheater.

Images