A method and system for generating superheated steam at normal pressure

Abstract

The present invention relates to the technical field of superheated steam generation, and specifically to a method and system for generating super-high temperature superheated steam at normal pressure. A method for generating super-high temperature superheated steam at normal pressure: introducing and igniting a predetermined proportion of hydrogen and oxygen mixed into an evacuated combustion chamber under normal pressure to generate a super-high temperature environment; introducing a portion of saturated steam into the ignited combustion chamber, a portion of gaseous water molecules in the saturated steam are decomposed into hydrogen and oxygen and rapidly burn, and the super-high temperature environment is further enhanced; the remaining saturated steam undergoes a first direct heat exchange in the combustion chamber, the liquid water is rapidly vaporized, and the gaseous water is superheated to generate super-high temperature superheated steam; the super-high temperature superheated steam discharged from the combustion chamber is combined with another portion of saturated steam in a steam superheating furnace for a second direct heat exchange, and after water vapor separation, super-high temperature superheated steam at normal pressure is obtained. The present invention provides a method and system for generating super-high temperature superheated steam at normal pressure with high heat exchange efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of superheated steam generation, and in particular to a method and system for generating superheated steam at normal pressure and ultra-high temperature. Background Art

[0002] This section merely provides background information related to the present disclosure and may not constitute prior art.

[0003] The existing superheated steam generation technology mainly adopts indirect heat exchange to heat saturated steam to achieve gasification and superheating. There are generally problems such as low heat exchange efficiency, uneven heat exchange, easy oxidation and damage of heat exchange metal materials, and low steam superheat temperature. Generally, it can only produce low-temperature superheated steam (200-500℃) and medium-temperature superheated steam (500-700℃), and it is difficult to produce high-temperature superheated steam (700-1000℃) and ultra-high-temperature superheated steam (above 1000℃); and it is generally medium-pressure superheated steam (1-5MPa) and high-pressure superheated steam (5-10MPa), and the superheated steam pressure even reaches supercritical (22MPa) and ultra-supercritical (25MPa). The steam superheating process equipment is complicated, and industrial applications are seriously restricted by steam pressure.

[0004] Since it is difficult to produce atmospheric pressure ultra-high temperature superheated steam (0.1-0.3MPa, above 1000℃) with existing technology, it cannot meet the use requirements of atmospheric pressure ultra-high temperature superheated steam in many industries such as chemical industry, power generation, steel, printing and dyeing, pharmaceuticals, papermaking, crude oil mining, etc. In addition, the existing production method has the problems of low heat exchange efficiency and easy oxidation damage of heat exchange metal materials. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art that it is difficult to produce atmospheric pressure ultra-high temperature superheated steam, and the heat exchange efficiency is low and the heat exchange metal materials are easily oxidized and damaged, thereby providing a atmospheric pressure ultra-high temperature superheated steam generation method and generation system with high heat exchange efficiency and the ability to avoid the easy oxidation and damage of the heat exchange metal materials.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for generating ultra-high temperature superheated steam at normal pressure, comprising the following steps:

[0008] Under normal pressure, a mixture of hydrogen and oxygen in a predetermined proportion is introduced into the evacuated combustion chamber and ignited to generate an ultra-ultra-high temperature environment; a portion of saturated steam is introduced into the ignited combustion chamber, wherein a portion of gaseous water molecules in the saturated steam are decomposed into hydrogen and oxygen and rapidly burn, further enhancing the ultra-ultra-high temperature environment; the remaining saturated steam undergoes a first direct heat exchange in the combustion chamber, liquid water is rapidly vaporized, and gaseous water is superheated to generate ultra-ultra-high temperature superheated steam; the ultra-ultra-high temperature superheated steam discharged from the combustion chamber is combined with another portion of saturated steam in a steam superheating furnace for a second direct heat exchange, and after water vapor separation, ultra-ultra-high temperature superheated steam at normal pressure is obtained.

[0009] Optionally, a portion of saturated steam is passed into the center of the combustion chamber from the top, hydrogen and oxygen surround the portion of saturated steam and pass into the combustion chamber from the top, and another portion of saturated steam is passed into the steam superheater from the side along a tangential direction.

[0010] Optionally, the combustion chamber and the steam superheater are evacuated by introducing saturated steam from both the top and the side.

[0011] Optionally, the ultra-high temperature superheated steam merges with another part of the saturated steam to form a steam external vortex flow, and the gaseous water in the saturated steam is pushed to the furnace wall under the action of centrifugal force to complete the water vapor separation, and the liquid water continues to be vaporized while flowing down the furnace wall. When the ultra-high temperature superheated steam external vortex flow reaches the cone at the bottom of the steam superheater, it reverses from bottom to top in the same rotation direction to form an inward vortex flow.

[0012] Optionally, the method also includes a step of cooling the steam superheater furnace simultaneously.

[0013] Optionally, the normal pressure is 0.1-0.3MPa, the molar ratio of hydrogen to oxygen is 2:1, the temperature of the ultra-high temperature superheated steam is 1500-1800°C, and the temperature of the normal pressure ultra-high temperature superheated steam is not less than 1000°C.

[0014] A normal pressure ultra-high temperature superheated steam generation system is also provided, which generates normal pressure ultra-high temperature superheated steam by using the method described, comprising:

[0015] A steam superheating furnace having a second nozzle for allowing saturated steam to enter, a furnace body and a furnace cover;

[0016] A plurality of ultra-high temperature superheated steam generators are distributed in the furnace body at intervals along the circumferential direction, wherein the ultra-high temperature superheated steam generator has a first nozzle allowing saturated steam to enter, a burner allowing hydrogen and oxygen to enter, and a combustion chamber for combustion, and a plurality of ultra-high temperature superheated steam discharge holes are provided on the bottom wall and side walls of the combustion chamber.

[0017] Optionally, the first nozzle is arranged at the top center of the ultra-high temperature superheated steam generator, a plurality of burners are arranged around the first nozzle, and a plurality of second nozzles are arranged along the tangential direction of the furnace body.

[0018] Optionally, the upper part of the furnace body is a cylinder, the lower part is a cone, and a furnace cover is provided on the top. An ultra-high temperature superheated steam conduit is also provided in the furnace body to guide the atmospheric pressure ultra-high temperature superheated steam out of the furnace body.

[0019] Optionally, the furnace body is further provided with a water cooling jacket, the upper part of the water cooling jacket is provided with a cold water inlet, a hot water outlet and a steam outlet, and the bottom is provided with a drain pipe.

[0020] The technical solution of the present invention has the following advantages:

[0021] 1. The present invention provides a method for generating ultra-high temperature superheated steam at normal pressure, which utilizes the characteristics of extremely fast combustion speed and extremely high combustion temperature of premixed hydrogen and oxygen to generate an ultra-ultra-high temperature environment of 2000-2200°C, and directly exchanges heat with a part of saturated steam to generate ultra-ultra-high temperature superheated steam of 1500-1800°C, and then merges with another part of saturated steam in a steam superheating furnace for heat exchange again, and obtains ultra-high temperature superheated steam at normal pressure after water vapor separation. The ultra-high temperature superheated steam directly exchanges heat with the saturated steam in the steam superheater. Due to the large heat exchange space, the heat exchange is uniform and rapid, and the heat exchange efficiency is extremely high. When a part of the saturated steam is passed into the ultra-high temperature environment of the combustion chamber, a part of the gaseous water molecules are decomposed into hydrogen and oxygen and burn rapidly, and the ultra-high temperature environment is further enhanced. The liquid water is vaporized and superheated to produce ultra-high temperature superheated steam of 1500-1800℃. In addition, the combustion chamber is emptied before the hydrogen and oxygen are ignited, which effectively avoids the oxidation damage of the heat exchange metal materials and completely eliminates the generation of NO during ultra-high temperature combustion. X , achieving clean production without any solid, liquid or gaseous pollutant emissions.

[0022] 2. The present invention provides a method for generating ultra-high temperature superheated steam at normal pressure, in which a flame of premixed hydrogen and oxygen surrounds a portion of saturated steam and enters the combustion chamber from the top, penetrating the saturated steam, so that more gaseous water molecules can be decomposed into hydrogen and oxygen and burn rapidly, continuing to enhance the ultra-high temperature environment of the combustion chamber, further improving the heat exchange efficiency, and reducing the volume of the combustion chamber.

[0023] 3. The present invention provides a method for generating superheated steam at atmospheric pressure, which evacuates the combustion chamber and the steam superheater by introducing saturated steam from the top and the side at the same time. The working medium also serves as an air isolation medium, which not only prevents the metal materials of the system from being oxidized and damaged at high temperatures, but also completely eliminates the generation of NO during superheated combustion. X, and no other media will be introduced to ensure product quality.

[0024] 4. The present invention provides a method for generating ultra-high temperature superheated steam at normal pressure, wherein the superheated furnace has a steam-water separation function, so the present invention can ensure the dryness requirement of the ultra-high temperature superheated steam.

[0025] 5. The present invention provides a method for generating ultra-high temperature superheated steam at normal pressure, wherein the process flow of combustion and heat exchange is carried out under the pressure condition of 0.1-0.3 MPa to ensure the generation of ultra-high temperature superheated steam at normal pressure.

[0026] 6. The present invention provides a method for generating superheated steam at normal pressure and at ultra-high temperature, and cools the steam superheating furnace to ensure the safety of the furnace body of the steam superheating furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of a normal pressure ultra-high temperature superheated steam generation system provided by the present invention;

[0029] Figure 2 Schematic diagram of an ultra-high temperature superheated steam generator.

[0030] Reference numerals:

[0031] 1. steam superheating furnace, 11. furnace body, 12. furnace cover, 13. ultra-high temperature superheated steam conduit, 14. second nozzle;

[0032] 2. an ultra-high temperature superheated steam generator, 21. a combustion chamber, 22. a burner, 23. a first nozzle, 24. an ultra-high temperature superheated steam discharge hole;

[0033] 3. Water-cooling jacket, 31. Cold water inlet, 32. Hot water outlet, 33. Steam outlet, 34. Drain pipe, 35. Stop valve, 36. Jacket. DETAILED DESCRIPTION

[0034] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0035] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "an" and "an" as used herein may also be meant to include the plural forms. The terms "comprise", "include" and "have" are inclusive and therefore specify the presence of stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0036] Although the terms first, second, etc. may be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. In addition, in the description of the present invention, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0037] For ease of description, spatial relative terms can be used in the text to describe the relationship of an element or feature relative to another element or feature as shown in the figure, and these relative terms are, for example, "front", "rear", "middle", "inside", "longitudinal", "lateral", "side", "vertical", "outside", etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation in addition to the orientation depicted in the figure. For example, if the mechanism in the figure flips, the element described as "below other elements or features" or "below other elements or features" will be subsequently oriented to "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include the orientation on and below. The mechanism can be oriented in addition (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0038] Example 1

[0039] This embodiment provides a method for generating atmospheric pressure ultra-high temperature superheated steam, comprising the following steps:

[0040] Under normal pressure of 0.1-0.3Mpa, saturated steam is introduced into the combustion chamber and the steam superheater from the top and the side at the same time to exhaust the air in the combustion chamber and the steam superheater, so as to avoid oxidation damage of the metal material in the combustion chamber at high temperature and prevent the ultra-high temperature combustion from producing NO. X .

[0041] Premixed hydrogen and oxygen with a molar ratio of 2:1 are introduced into the emptied combustion chamber from the top and ignited to produce an ultra-high temperature environment of 2000-2200°C. The premixed hydrogen and oxygen burners are arranged around a portion of the saturated steam introduced from the top, and the premixed hydrogen and oxygen flame penetrates the saturated steam in the combustion chamber.

[0042] A portion of saturated steam is introduced into the ignited combustion chamber from the top, wherein a portion of gaseous water molecules in the saturated steam are decomposed into hydrogen and oxygen and burn rapidly, continuing to enhance the ultra-high temperature environment of 2000-2200°C; the remaining saturated steam undergoes the first direct heat exchange in the combustion chamber, liquid water is rapidly vaporized, and gaseous water is superheated; hydrogen and oxygen input from the top are decomposed with gaseous water molecules to produce hydrogen and oxygen, which burn in the combustion chamber to produce ultra-high temperature superheated steam of 1800-2000°C, which is mixed with the saturated steam introduced from the top and vaporized and superheated to form ultra-high temperature superheated steam of 1500-1800°C, and then discharged from the combustion chamber into the steam superheating furnace.

[0043] The ultra-high temperature superheated steam discharged from the combustion chamber merges with another part of the saturated steam introduced from the side in the steam superheating furnace to form a steam external vortex flow. This part of the saturated steam and the ultra-high temperature superheated steam undergo a second direct heat exchange in the external vortex flow. The liquid water in the saturated steam is vaporized and superheated. A small part of the liquid water is pushed to the furnace wall under the action of centrifugal force to achieve water vapor separation. The liquid water absorbs heat and vaporizes on the furnace wall, and then enters the ultra-high temperature superheated steam external vortex flow to continue being superheated.

[0044] When the ultra-high temperature superheated steam external vortex reaches the lower part of the steam superheater cone, it reverses from the central axis of the steam superheater from bottom to top in the same direction of rotation and continues to make spiral motion. The ultra-high temperature superheated steam forms an internal vortex flow and is discharged from the steam superheater from the top to obtain normal pressure ultra-high temperature superheated steam with a pressure of 0.1-0.3MPa and a temperature greater than 1000℃.

[0045] During the above working process, the steam superheater is cooled and protected at the same time. After the boiler is shut down and cooled, drainage is carried out.

[0046] It should be noted that the present method can produce both atmospheric pressure ultra-high temperature superheated steam and atmospheric pressure high temperature superheated steam and atmospheric pressure medium temperature superheated steam. The amount of hydrogen, oxygen and saturated steam introduced can be flexibly set according to demand to obtain atmospheric pressure superheated steam of the required temperature.

[0047] In addition, hydrogen and oxygen can also be introduced into the center of the combustion chamber, and saturated steam surrounds the hydrogen and oxygen and is introduced into the combustion chamber.

[0048] Example 2

[0049] like Figure 1 and Figure 2 A specific embodiment of the atmospheric pressure ultra-high temperature superheated steam generation system shown in the figure uses the method described in Example 1 to generate atmospheric pressure ultra-high temperature superheated steam, including a steam superheating furnace 1, an ultra-ultra-high temperature superheated steam generator 2 arranged in the steam superheating furnace 1, and a water-cooled jacket 3 arranged outside the steam superheating furnace 1.

[0050] The steam superheating furnace 1 comprises a furnace cover 12 , a second nozzle 14 for allowing saturated steam to enter, a furnace body 11 and an ultra-high temperature superheated steam conduit 13 arranged on the central axis of the upper part of the furnace body 11 .

[0051] The furnace body 11 is cylindrical at the top and conical at the bottom, and is made of stainless steel. The interior of the furnace cover 12 is made of high-temperature resistant ceramics, and the exterior is made of non-metallic thermal insulation materials such as mineral fibers. The ultra-high temperature superheated steam conduit 13 is arranged on the central axis of the upper part of the furnace body 11, and the top extends to the outside of the furnace cover 12 to discharge ultra-high temperature superheated steam. The upper cylindrical side wall of the furnace body 11 is provided with a saturated steam tangential nozzle, i.e., the second nozzle 14. The second nozzle 14 is arranged along the tangent direction of the furnace body 11, and the number is 3-6, which is consistent with the number of the combustion chambers 21.

[0052] A plurality of ultra-high temperature superheated steam generators 2 are distributed in the furnace body 11 at intervals along the circumferential direction. The ultra-high temperature superheated steam generator 2 has a first nozzle 23 for allowing saturated steam to enter, a burner 22 for allowing hydrogen and oxygen to enter, and a combustion chamber 21 for combustion.

[0053] The combustion chamber 21 is a hollow cylindrical shape, and a plurality of ultra-high temperature superheated steam discharge holes 24 are respectively provided on the bottom wall and the side wall. The holes on the bottom wall are annular holes distributed in concentric circles, and the holes on the side wall are distributed at intervals along the axis extension direction. The combustion chamber 21 material can be selected from tungsten, molybdenum or other metal alloy materials that can withstand temperatures of 2200-2400°C, and non-metallic materials such as zirconium dioxide fiber that can withstand temperatures of 2200-2400°C can also be selected. The number of combustion chambers 21 is 3-6, which is consistent with the number of saturated steam tangential nozzles.

[0054] The first nozzle 23 is disposed at the top center of the ultra-high temperature superheated steam generator 2 , and a plurality of burners 22 are disposed around the first nozzle 23 .

[0055] The water cooling jacket 3 includes a jacket body 36 , a cold water inlet 31 , a hot water outlet 32 ​​, a steam outlet 33 and a drain pipe 34 .

[0056] The casing 36 is made of stainless steel, and an insulation layer is arranged outside the casing 36 for heat preservation. A cold water inlet 31 and a hot water outlet 32 ​​are arranged opposite to each other on the upper side wall of the casing 36, a steam outlet 33 is arranged on the top, and a drain pipe 34 is arranged on the bottom. A stop valve 35 is arranged on the drain pipe 34. Cold water is input from the cold water inlet 31 to provide water cooling protection for the furnace body of the steam superheater 1, hot water is output from the hot water outlet 32, and jacket steam is output from the steam outlet 33; in the working state, the stop valve 35 is closed, and after the furnace is stopped and cooled, the stop valve 35 is opened to discharge the water in the jacket.

[0057] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A method for generating ultra-high temperature superheated steam at normal pressure, characterized in that: The following steps are involved: Under normal pressure, hydrogen and oxygen mixed in a predetermined proportion are introduced into the evacuated combustion chamber and ignited to generate an ultra-ultra-high temperature environment; a portion of saturated steam is introduced into the ignited combustion chamber, wherein a portion of gaseous water molecules in the saturated steam are decomposed into hydrogen and oxygen and rapidly burned, thereby continuing to enhance the ultra-ultra-high temperature environment; the remaining saturated steam undergoes a first direct heat exchange in the combustion chamber, wherein liquid water is rapidly vaporized and gaseous water is superheated to generate ultra-ultra-high temperature superheated steam; the ultra-ultra-high temperature superheated steam discharged from the combustion chamber is combined with another portion of saturated steam in a steam superheating furnace for a second direct heat exchange, and after water vapor separation, ultra-ultra-high temperature superheated steam at normal pressure is obtained, wherein the normal pressure is 0.1-0.3 MPa, the temperature of the ultra-ultra-high temperature superheated steam is 1500-1800°C, and the temperature of the ultra-ultra-high temperature superheated steam at normal pressure is not less than 1000°C.

2. The method for generating normal pressure ultra-high temperature superheated steam according to claim 1, characterized in that: A portion of saturated steam is introduced into the center of the combustion chamber from the top, hydrogen and oxygen surround this portion of saturated steam and are introduced into the combustion chamber from the top, and another portion of saturated steam is introduced into the steam superheater from the side along a tangential direction.

3. The method for generating normal pressure ultra-high temperature superheated steam according to claim 2, characterized in that: The combustion chamber and the steam superheater are evacuated by introducing saturated steam from both the top and the side.

4. The method for generating normal pressure ultra-high temperature superheated steam according to any one of claims 1 to 3, characterized in that: The ultra-high temperature superheated steam merges with another part of the saturated steam to form a steam external vortex. The gaseous water in the saturated steam is pushed to the furnace wall under the action of centrifugal force to complete the water vapor separation. The liquid water continues to be vaporized while flowing down the furnace wall. When the ultra-high temperature superheated steam external vortex reaches the cone at the bottom of the steam superheater, it reverses from bottom to top in the same rotation direction to form an internal vortex.

5. The method for generating normal pressure ultra-high temperature superheated steam according to any one of claims 1 to 3, characterized in that: The method also includes the step of cooling the steam superheater furnace at the same time.

6. The method for generating normal pressure ultra-high temperature superheated steam according to any one of claims 1 to 3, characterized in that: The molar ratio of hydrogen to oxygen is 2:

1.

7. A normal pressure ultra-high temperature superheated steam generation system, characterized in that: The method according to any one of claims 1 to 6 is used to generate atmospheric pressure ultra-high temperature superheated steam, comprising: A steam superheating furnace (1) having a second nozzle (14) for allowing saturated steam to enter, a furnace body (11) and a furnace cover (12); A plurality of ultra-high temperature superheated steam generators (2) are distributed in the furnace body (11) at intervals along the circumferential direction, the ultra-high temperature superheated steam generators (2) having a first nozzle (23) for allowing saturated steam to enter, a burner (22) for allowing hydrogen and oxygen to enter, and a combustion chamber (21) for performing combustion, wherein a plurality of ultra-high temperature superheated steam discharge holes (24) are provided on the bottom wall and side walls of the combustion chamber (21).

8. The atmospheric pressure ultra-high temperature superheated steam generation system according to claim 7, characterized in that: The first nozzle (23) is arranged at the top center of the ultra-high temperature superheated steam generator (2), a plurality of burners (22) are arranged around the first nozzle (23), and a plurality of second nozzles (14) are arranged along the tangent direction of the furnace body (11).

9. The atmospheric pressure ultra-high temperature superheated steam generation system according to claim 7 or 8, characterized in that: The upper part of the furnace body (11) is cylindrical, the lower part is conical, and a furnace cover (12) is provided on the top. An ultra-high temperature superheated steam conduit (13) is also provided in the furnace body (11) to guide the atmospheric pressure ultra-high temperature superheated steam out of the furnace body (11).

10. The atmospheric pressure ultra-high temperature superheated steam generation system according to claim 9, characterized in that: The furnace body (11) is also provided with a water cooling jacket (3) on the outside. The upper part of the water cooling jacket (3) is provided with a cold water inlet (31), a hot water outlet (32) and a steam outlet (33), and the bottom is provided with a drain pipe (34).

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