Four-in-one unit and device for nitric acid production

Abstract

The utility model discloses a four-in-one unit and device for nitric acid production, and relates to the technical field of nitric acid production equipment. The nitric acid production four-in-one unit comprises an air compressor, a nitric oxide compressor, an expansion machine and a driving module, the driving module comprises a driving unit and a gearbox, the driving unit is driven by electricity or steam, the driving unit is connected with the input end of the gearbox, the gearbox is provided with three output ends, and the three output ends are connected with the driving unit. And each output end is correspondingly connected with one of the air compressor, the nitrogen oxide compressor and the expansion machine. The four-in-one unit for nitric acid production is more compact in structure and smaller in size.

Description

Technical Field

[0001] The present application relates to the technical field of nitric acid production equipment, and in particular to a four-in-one unit and device for nitric acid production. Background Art

[0002] At present, the existing nitric acid device four-in-one unit system structure is composed of four devices connected in series: air compressor, NOx compressor, expander and steam turbine. A speed change gear box is set between the steam turbine and the air compressor to ensure that each device runs at the required speed. The rotors are connected together through couplings between each device and between the device and the gearbox. The entire unit structure composed of this has a large axial length, resulting in a large volume of the entire unit and a large footprint after the unit structure is installed. Utility Model Content

[0003] In view of this, the present application provides a four-in-one unit and device for producing nitric acid, aiming to solve one of the technical problems in the prior art.

[0004] To achieve the above objectives, the technical solutions adopted in this application are as follows:

[0005] In a first aspect, an embodiment of the present application provides a four-in-one nitric acid production unit, comprising:

[0006] Air compressor;

[0007] Nitrogen oxide compressor;

[0008] Expander;

[0009] The drive module comprises a drive unit and a gearbox, wherein the drive unit is driven by electricity or steam, the drive unit is connected to the input end of the gearbox, and the gearbox is provided with three output ends, each of the output ends is correspondingly connected to one of the air compressor, the nitrogen oxide compressor and the expander.

[0010] In one embodiment of the first aspect, the driving unit includes a first driving machine, the gearbox includes a primary transmission shaft, the input end of the gearbox is arranged on the primary transmission shaft, and the first driving machine is connected to the primary transmission shaft.

[0011] In one embodiment of the first aspect, the gearbox further comprises:

[0012] A first and second-stage transmission shaft, wherein the first and second-stage transmission shaft is provided with an output end;

[0013] a second secondary transmission shaft, the second secondary transmission shaft being provided with one of the output ends;

[0014] A third secondary transmission shaft, wherein the third secondary transmission shaft is provided with an output end; the first secondary transmission shaft, the second secondary transmission shaft and the third secondary transmission shaft are respectively connected to the first transmission shaft.

[0015] In one embodiment of the first aspect, the output end of the first secondary transmission shaft is connected to the air compressor; the output end of the second secondary transmission shaft is connected to the nitrogen oxide compressor; and the output end of the third secondary transmission shaft is connected to the expander.

[0016] In one of the embodiments of the first aspect, the driving unit further includes a second driving machine and a clutch, and the second driving machine, the clutch and the gearbox are connected in sequence.

[0017] In one embodiment of the first aspect, the second driving machine, the clutch and the primary transmission shaft are connected in sequence.

[0018] In one embodiment of the first aspect, when the clutch is in a connected state, the second drive engine, the clutch and the gearbox are in a connected state, and the second drive engine drives the gearbox; when the clutch is in a disconnected state, the first drive engine drives the gearbox.

[0019] In one embodiment of the first aspect, the first driving machine is a steam turbine, and the second driving machine is an electric motor.

[0020] In a second aspect, the present application also provides a nitric acid production device, including:

[0021] The four-in-one nitric acid production unit in any of the above embodiments;

[0022] an oxidation furnace connected to the air compressor;

[0023] a heat exchanger connected between the air compressor and the oxidation furnace;

[0024] An absorption tower is connected to the nitrogen oxide compressor and the expander.

[0025] In one embodiment of the second aspect, the driving unit includes a first driving machine, and the nitric acid production device also includes a boiler, and the boiler is connected to the first driving machine and the oxidation furnace.

[0026] Compared with the prior art, the beneficial effects of the present application are as follows: the present application proposes a four-in-one unit for nitric acid production, including an air compressor, a nitrogen oxide compressor, an expander and a drive module, the drive module including a drive unit and a gearbox, the drive unit is driven by electricity or steam, and the gearbox is provided with three output ends, each of which is connected to one of the air compressor, the nitrogen oxide compressor and the expander. In this way, by installing the air compressor, the nitrogen oxide compressor and the expander on the gearbox as accessories, no additional coupling is required for connection, and the whole unit is very compact and highly integrated, reducing the volume of the whole unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The schematic diagram of the structure of a four-in-one nitric acid production unit in the related art is shown;

[0029] Figure 2 One of the structural schematic diagrams of a nitric acid production device in some embodiments of the present application is shown;

[0030] Figure 3 The second structural schematic diagram of the nitric acid production device in some embodiments of the present application is shown.

[0031] Description of the main component symbols: 1000-nitric acid production device; 100-nitric acid production four-in-one unit; 200-oxidation furnace; 300-heat exchanger; 400-absorption tower; 500-boiler;

[0032] 110-driving module; 111-driving unit; 1111-first driving machine; 1112-second driving machine; 1113-clutch; 112-gearbox; 1121-first and second driving shafts; 1122-first and second driving shafts; 1123-second and second driving shafts; 1124-third and second driving shafts;

[0033] 120-air compressor; 130-nitrogen oxide compressor; 140-expander. DETAILED DESCRIPTION

[0034] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] See also Figure 1The existing four-in-one unit of the nitric acid device is composed of four devices connected in series: an air compressor, a nitrogen oxide compressor, an expander and a steam turbine. Specifically, the rotor of the steam turbine and one of the gear shafts of the speed change gearbox are generally connected through a coupling, and the other gear shaft of the speed change gearbox and the rotors of the air compressor, the nitrogen oxide compressor and the expander are connected together through three couplings. In this way, the transmission wheelbase of the rotor system composed of the gear shaft of the gearbox, the rotor of the air compressor, the rotor of the nitrogen oxide compressor and the rotor of the expander is very long, resulting in an excessively large volume of the entire unit.

[0040] like Figure 2 As shown, the embodiment of the present application provides a nitric acid production four-in-one unit 100, which is mainly used to produce nitric acid. The nitric acid production four-in-one unit 100 includes an air compressor 120, a nitrogen oxide compressor 130, an expander 140 and a drive module 110. Among them, the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 are respectively connected to the drive module 110.

[0041] Specifically, the driving module 110 includes a driving unit 111 and a gearbox 112. The driving unit 111 is driven by electricity or steam. The driving unit 111 is connected to the input end of the gearbox 112. The gearbox 112 is provided with three output ends, each of which is correspondingly connected to one of the air compressor 120, the nitrogen oxide compressor 130 and the expander 140. In this way, by installing the air compressor, the nitrogen oxide compressor 130 and the expander 140 as accessories on the gearbox 112, no additional coupling is required for connection, and the entire unit is very compact and highly integrated, reducing the volume of the entire unit.

[0042] In one embodiment, the driving unit 111 includes a first driving machine 1111, the gearbox 112 includes a primary transmission shaft 1121, the input end of the gearbox 112 is arranged on the primary transmission shaft 1121, and the first driving machine 1111 is connected to the primary transmission shaft 1121. The primary transmission shaft 1121 is connected to the output end of the first driving machine 1111, and outputs the torque and speed to the secondary transmission shaft.

[0043] In this embodiment, as preferred, the gearbox 112 also includes a first secondary transmission shaft 1122 , a second secondary transmission shaft 1123 and a third secondary transmission shaft 1124 .

[0044] Among them, the first secondary transmission shaft 1122, the second secondary transmission shaft 1123 and the third secondary transmission shaft 1124 are respectively connected to the primary transmission shaft 1121. A gear pair in which a driving gear drives a driven gear is respectively set between each secondary transmission shaft and the primary transmission shaft 1121. The speed ratio (tooth ratio of large and small gears) of each gear pair will be set according to the rotor speed required for the operation of the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 actually connected thereto, and different gear ratio parameters will be set.

[0045] The first secondary transmission shaft 1122 is provided with an output end, the second secondary transmission shaft 1123 is provided with an output end, and the third secondary transmission shaft 1124 is provided with an output end, so that each secondary transmission shaft is connected to one of the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 accordingly.

[0046] In other embodiments, the gearbox 112 further includes a first secondary transmission shaft 1122 and a second secondary transmission shaft 1123 .

[0047] Among them, the first and second transmission shafts 1122 and the second and second transmission shafts 1123 are respectively connected to the first transmission shaft 1121.

[0048] The first secondary transmission shaft 1122 is provided with two output ends, and the second secondary transmission shaft 1123 is provided with one output end, so that two of the air compressor 120 , the nitrogen oxide compressor 130 and the expander 140 are connected to the first secondary transmission shaft 1122 , and the remaining one is connected to the second secondary transmission shaft 1123 .

[0049] Compared with the above-mentioned structure of the gearbox 112 including the first and second transmission shafts 1122, the second and second transmission shafts 1123 and the third and second transmission shafts 1124, although only the first and second transmission shafts 1122 and the second and second transmission shafts 1123 are provided to reduce the number of secondary transmission shafts, the load on the first and second transmission shafts 1122 is large and the operation is not stable enough.

[0050] In this embodiment, the output end of the first secondary transmission shaft 1122 is connected to the air compressor 120 , the output end of the second secondary transmission shaft 1123 is connected to the nitrogen oxide compressor 130 , and the output end of the third secondary transmission shaft 1124 is connected to the expander 140 .

[0051] In other embodiments, exemplarily, the output end of the first secondary transmission shaft 1122 is connected to the air compressor 120 , the output end of the second secondary transmission shaft 1123 is connected to the expander 140 , and the output end of the third secondary transmission shaft 1124 is connected to the nitrogen oxide compressor 130 .

[0052] Exemplarily, the output end of the first secondary transmission shaft 1122 is connected to the expander 140 , the output end of the second secondary transmission shaft 1123 is connected to the air compressor 120 , and the output end of the third secondary transmission shaft 1124 is connected to the nitrogen oxide compressor 130 .

[0053] In one embodiment, the driving unit 111 further includes a second driving machine 1112 and a clutch 1113, and the second driving machine 1112, the clutch 1113 and the gearbox 112 are connected in sequence. By setting the clutch 1113, the second driving machine 1112 and the gearbox 112 are controlled to be connected or disconnected, so that the gearbox 112 is driven by the second driving machine 1112.

[0054] Specifically, when the clutch 1113 is in a connected state, the second driving engine 1112, the clutch 1113 and the gearbox 112 are in a connected state, and the second driving engine 1112 drives the gearbox 112; when the clutch 1113 is in a disconnected state, the first driving engine 1111 drives the gearbox 112.

[0055] In one embodiment, the second driving machine 1112, the clutch 1113 and the primary transmission shaft are connected in sequence, and the first driving machine 1111 and the second driving machine 1112 are connected to the primary transmission shaft respectively, so that the structure of the driving module 110 is simpler.

[0056] Please refer to Figure 1 and Figure 2 In the related technology, the steam turbine is used as the driving module. Since the steam turbine needs a certain amount of steam to drive the operation, the related technology usually adds a boiler to the device to produce a certain amount of steam to drive the steam turbine. Before the nitric acid production four-in-one unit is started, the oxidation furnace cannot generate heat to supply the steam boiler to produce steam. Therefore, when the unit is started, additional steam is required to drive the steam turbine. Only when the entire equipment is fully operational can the steam required to drive the steam turbine be self-sufficient. This not only makes the entire device more complicated, but also adds a lot of large equipment.

[0057] For the above questions, please refer to Figure 2 and Figure 3 In one embodiment, the first driving machine 1111 is a steam turbine, and the second driving machine 1112 is a motor. The steam turbine and the motor are arranged at the same end of the primary transmission shaft 1121, or the steam turbine is arranged at one end of the primary transmission shaft 1121, and the motor is arranged at the other end of the primary transmission shaft 1121.

[0058] The motor and the steam turbine are respectively connected to the input end of the gearbox 112 to drive the gearbox 112 in a staggered manner.

[0059] Specifically, the first driving machine 1111 is a steam turbine. When the unit is started or a fault occurs inside the nitric acid production device 1000, the oxidation furnace 200 cannot generate enough steam to drive the steam turbine, so the unit is blocked from starting or running. Therefore, an external device is required to provide additional steam to drive the steam turbine, so that the entire unit can be started or run. By adding another driving machine to start or run the unit, it is not necessary to provide additional steam from an external device, which simplifies the structure of the nitric acid production four-in-one unit 100 and improves the production efficiency of the nitric acid production device 1000.

[0060] The gear-speed-increasing assembled nitric acid production four-in-one unit 100 structure, which is composed of an air compressor 120, a nitrogen oxide compressor 130, an expander 140, a steam turbine, a motor and a gearbox 112 as main power equipment, has the advantages of compact structure, high integration and short shaft length, thereby improving the stability and reliability of the operation of the nitric acid production four-in-one unit 100.

[0061] Please refer to Figure 2 and Figure 3 The embodiment of the present application also provides a nitric acid production device 1000, including the nitric acid production four-in-one unit 100, an oxidation furnace 200, a heat exchanger 300 and an absorption tower 400 in any of the above embodiments.

[0062] The oxidation furnace 200 is connected to the air compressor 120 , the heat exchanger 300 is connected between the air compressor 120 and the oxidation furnace 200 , and the absorption tower 400 is connected to the nitrogen oxide compressor 130 and the expander 140 .

[0063] In one embodiment, the driving unit 111 includes a first driving machine 1111 , and the nitric acid production device 1000 further includes a boiler 500 , and the boiler 500 is connected to the first driving machine 1111 and the oxidation furnace 200 .

[0064] The nitric acid production method of the nitric acid production device 1000 is as follows:

[0065] The air compressor compresses the air to a certain pressure, and the compressed air is mixed with ammonia (ammonia can be provided by ammonia production equipment in the production plant), and then enters the oxidation furnace 200 for combustion reaction to generate nitrogen oxide gas;

[0066] The heat generated by the combustion is supplied to the boiler 500 for steam production, and the steam is delivered to the steam turbine for driving it to operate and perform work;

[0067] After the nitrogen oxide gas is cooled by heat exchange in the heat exchanger, it enters the nitrogen oxide compressor 130 for compression;

[0068] The compressed nitrogen oxide gas enters the absorption tower 400 to produce nitric acid;

[0069] The gas (tail gas) escaping from the top of the absorption tower 400 is subjected to certain treatment, enters the expander 140 to perform work, and is then discharged into the atmosphere.

[0070] Among them, during the startup phase of the boiler 500 without steam production, the steam turbine cannot be started, and the motor is connected to the primary transmission shaft 1121 through the engagement of the clutch 1113, driving the gearbox 112 and the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 connected to the gearbox 112.

[0071] When the startup is completed and the entire nitric acid plant enters the normal operation stage, the boiler 500 produces enough steam to supply the steam turbine. The clutch 1113 is disconnected, so that the motor is separated from the primary transmission shaft 1121, and the steam turbine drives the gearbox 112 and the air compressor 120 and the nitrogen oxide compressor 130 connected to the gearbox 112.

[0072] At the same time, the expander 140 performs tail gas treatment and also performs work and outputs it to the air compressor 120 and the nitrogen oxide compressor 130. This is equivalent to the steam turbine and the expander 140 acting as prime movers to perform work and input it into the air compressor 120 and the nitrogen oxide compressor 130, providing them with energy for compressed gas.

[0073] The method for producing nitric acid is simple and efficient, especially during the startup phase of the nitric acid production device 1000. There is no need to obtain additional steam by other methods to provide steam turbine driving when the unit is started, making the structure of the nitric acid production device 1000 more simple and efficient.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0075] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A four-in-one unit for producing nitric acid, characterized in that: include: Air compressor; Nitrogen oxide compressor; Expander; The drive module comprises a drive unit and a gearbox, wherein the drive unit is driven by electricity or steam, the drive unit is connected to the input end of the gearbox, and the gearbox is provided with three output ends, each of the output ends is correspondingly connected to one of the air compressor, the nitrogen oxide compressor and the expander.

2. The four-in-one nitric acid production unit according to claim 1, characterized in that: The driving unit includes a first driving machine, the gearbox includes a primary transmission shaft, the input end of the gearbox is arranged on the primary transmission shaft, and the first driving machine is connected to the primary transmission shaft.

3. The four-in-one nitric acid production unit according to claim 2, characterized in that: The gearbox also includes: A first and second-stage transmission shaft, wherein the first and second-stage transmission shaft is provided with an output end; a second secondary transmission shaft, the second secondary transmission shaft being provided with one of the output ends; A third secondary transmission shaft, wherein the third secondary transmission shaft is provided with an output end; the first secondary transmission shaft, the second secondary transmission shaft and the third secondary transmission shaft are respectively connected to the first transmission shaft.

4. The four-in-one nitric acid production unit according to claim 3, characterized in that: The output end of the first secondary transmission shaft is connected to the air compressor; the output end of the second secondary transmission shaft is connected to the nitrogen oxide compressor; The output end of the third secondary transmission shaft is connected to the expander.

5. The four-in-one nitric acid production unit according to any one of claims 2 to 4, characterized in that: The driving unit further includes a second driving machine and a clutch, and the second driving machine, the clutch and the gearbox are connected in sequence.

6. The four-in-one nitric acid production unit according to claim 5, characterized in that: The second driving machine, the clutch and the primary transmission shaft are connected in sequence.

7. The four-in-one nitric acid production unit according to claim 6, characterized in that: When the clutch is in a connected state, the second driving machine, the clutch and the gearbox are in a connected state, and the second driving machine drives the gearbox; when the clutch is in a disconnected state, the first driving machine drives the gearbox.

8. The four-in-one nitric acid production unit according to claim 5, characterized in that: The first driving machine is a steam turbine, and the second driving machine is an electric motor.

9. A nitric acid production device, characterized in that: include: The four-in-one nitric acid production unit according to any one of claims 1 to 8; an oxidation furnace connected to the air compressor; a heat exchanger connected between the air compressor and the oxidation furnace; An absorption tower is connected to the nitrogen oxide compressor and the expander.

10. The nitric acid production device according to claim 9, characterized in that: The driving unit includes a first driving machine, and the nitric acid production device also includes a boiler, which is connected to the first driving machine and the oxidation furnace.

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