阅读说明：本技术 一种硝酸装置能量回收机组 (Nitric acid device energy recuperation unit ) 是由 李旭晶 李宏安 陈余平 陈妍 王育红 刘拥军 王咏梅 周根标 王冬 黄靓 汪传美 于 2019-09-16 设计创作，主要内容包括：本发明提供了一种硝酸装置能量回收机组,包括尾气透平、NOx压缩机、汽轮机、第一齿轮箱和轴流压缩机,所述的尾气透平,包括机匣和安装在机匣内的转轴,机匣上安装有静叶,转轴的轮毂上安装有动叶；所述的尾气透平、NOx压缩机、汽轮机、第一齿轮箱和轴流压缩机依次同轴相连；所述的尾气透平的机匣上沿着轴向依次安装有5级静叶,转轴上沿着轴向依次安装有5级动叶,静叶和动叶依次交替布设。本发明的硝酸装置能量回收机组能量回收效率高,方案中汽轮机将机组拖动工作转速的95％,逐渐将机组负荷提升到装置点火生产所需要的负荷,检查装置运行符合点火要求后点火,调节机组负荷使之满足系统工艺要求。(The invention provides an energy recovery unit of a nitric acid device, which comprises a tail gas turbine, an NOx compressor, a steam turbine, a first gear box and an axial flow compressor, wherein the tail gas turbine comprises a casing and a rotating shaft arranged in the casing, a stationary blade is arranged on the casing, and a movable blade is arranged on a hub of the rotating shaft; the tail gas turbine, the NOx compressor, the steam turbine, the first gear box and the axial flow compressor are sequentially and coaxially connected; 5-stage static blades are sequentially arranged on a casing of the tail gas turbine along the axial direction, 5-stage movable blades are sequentially arranged on a rotating shaft along the axial direction, and the static blades and the movable blades are sequentially and alternately arranged. The nitric acid device energy recovery unit has high energy recovery efficiency, the steam turbine in the scheme drives the unit to 95 percent of the working rotating speed, the load of the unit is gradually increased to the load required by ignition production of the device, the device is ignited after the operation of the device meets the ignition requirement, and the load of the unit is adjusted to meet the process requirement of the system.)

1. The utility model provides a nitric acid device energy recuperation unit, includes tail gas turbine (7), NOx compressor (8), steam turbine (9), first gear box (10) and axial compressor (11), tail gas turbine (7), including the receiver with install pivot (2) in receiver (1), install quiet leaf (4) on receiver (1), install movable blade (5), its characterized in that on wheel hub (3) of pivot (2):

the tail gas turbine (7), the NOx compressor (8), the steam turbine (9), the first gear box (10) and the axial flow compressor (11) are sequentially and coaxially connected;

5 stages of static blades (4) are sequentially arranged on a casing (1) of the tail gas turbine (7) along the axial direction, 5 stages of movable blades (5) are sequentially arranged on a rotating shaft (2) along the axial direction, and the static blades (4) and the movable blades (5) are sequentially and alternately arranged;

the 5-stage static blades (4) are respectively a first-stage static blade (401), a second-stage static blade (402), a third-stage static blade (403), a fourth-stage static blade (404) and a fifth-stage static blade (405); the blade profile parameters at the blade profile diameter equalizing position of the 5-stage stationary blade (4) are respectively as follows:

the first-stage stationary blade (401) is 53.0mm in chord length, 35.1mm in blade width, 19.1mm in maximum thickness, 3.5 degrees in inlet geometric angle, 77.8 degrees in outlet geometric angle, 39.8mm in pitch and 10.3mm in throat width;

the second-stage stationary blade (402) has the chord length of 43.6mm, the blade width of 29mm, the maximum thickness of 15.4mm, the inlet geometric angle of-10.5 degrees, the outlet geometric angle of 76.7 degrees, the pitch of 34.6mm and the throat width of 10.1 mm;

the three-stage stationary blade (403) has the chord length of 43.6mm, the blade width of 29.7mm, the maximum thickness of 15.4mm, the inlet geometric angle of-10.9 degrees, the outlet geometric angle of 75.4 degrees, the pitch of 34.6mm and the throat width of 10.6 mm;

the four-stage stationary blade (404) has the chord length of 45.4mm, the blade width of 30.7mm, the maximum thickness of 16.3mm, the inlet geometric angle of-13.4 degrees, the outlet geometric angle of 76.1 degrees, the pitch of 33.4mm and the throat width of 10.5 mm;

the five-stage stationary blade (405) has the chord length of 49.6mm, the blade width of 36.8mm, the maximum thickness of 17.2mm, the inlet geometric angle of-15.3 degrees, the outlet geometric angle of 71.6 degrees, the pitch of 36.0mm and the throat width of 12.8 mm;

the 5-stage movable blade (5) is respectively a first-stage movable blade (501), a second-stage movable blade (502), a third-stage movable blade (503), a fourth-stage movable blade (504) and a fifth-stage movable blade (505), and the blade profile parameters at the blade profile uniform diameter of the 5-stage movable blade (5) are respectively as follows:

the chord length of the first-stage movable blade (501) is 45.5mm, the blade width is 30.2mm, the maximum thickness is 16.4mm, the inlet geometric angle is-11.9 degrees, the outlet geometric angle is 77.7 degrees, the pitch is 36.0mm, and the throat width is 9.4 mm;

the chord length of the secondary movable blade (502) is 45.7mm, the blade width is 31.4mm, the maximum thickness is 16.7mm, the inlet geometric angle is-9.7 degrees, the outlet geometric angle is 74.8 degrees, the pitch is 32.8mm, and the throat width is 9.2 mm;

the chord length of the three-stage movable blade (503) is 51.4mm, the blade width is 35mm, the maximum thickness is 16.7mm, the inlet geometric angle is-4.8 degrees, the outlet geometric angle is 74.6 degrees, the pitch is 30.5mm, and the throat width is 7.9 mm;

the four-stage movable blade (504) has the chord length of 59mm, the blade width of 41.2mm, the maximum thickness of 19.2mm, the inlet geometric angle of-1.2 degrees, the outlet geometric angle of 72.7 degrees, the pitch of 34mm and the throat width of 9.4 mm;

the five-stage movable blade (505) has the chord length of 65.5mm, the blade width of 51.4mm, the maximum thickness of 11.5mm, the inlet geometric angle of-11.9 degrees, the outlet geometric angle of 67.2 degrees, the pitch of 37mm and the throat width of 12.5 mm.

2. The nitric acid plant energy recovery unit of claim 1, wherein the number of first stage vanes (401) is 56, the number of second stage vanes (402) is 60, the number of third stage vanes (403) is 60, the number of fourth stage vanes (404) is 62, and the number of fifth stage vanes (405) is 62.

3. The nitric acid plant energy recovery unit of claim 1, wherein the number of blades of the first-stage blades (501) is 62, the number of blades of the second-stage blades (502) is 68, the number of blades of the third-stage blades (503) is 68, the number of blades of the fourth-stage blades (504) is 61, and the number of blades of the fifth-stage blades (505) is 56.

4. A nitric plant energy recovery unit according to claim 1, further comprising a second gearbox (12) and an electric motor (13) connected in series to the axial compressor (11).

Technical Field

The invention belongs to the field of nitric acid, relates to a nitric acid four-in-one unit adopting a double-pressurization method, and particularly relates to an energy recovery unit of a nitric acid device.

Background

Since 1905 the first factory production of nitric acid in the world, the nitric acid industry has developed for over one hundred years to become an industrial system with mature technology, reasonable design, complete product specification, comprehensive energy utilization and environmental protection. The current processes for producing nitric acid include atmospheric pressure process, full pressure process and synthetic process, which is represented by the French Grand-Paroisse process and is also called double pressure process.

The process requires ammoxidation at medium pressure and NO2 absorption at high pressure. And the tail gas turbine is used for recovering residual energy after NOx is absorbed and drives the unit together with the steam turbine.

With the promotion of environmental protection and energy conservation strategies in economic construction of China, the energy recovery device of the industrial process is an energy-saving and environment-friendly product which is widely popularized by the nation. At present, the applicant has developed different types of energy recovery devices such as nitric acid tail gas waste heat and residual pressure energy recovery devices (nitric acid device four-in-one units). The nitric acid device four-in-one unit is the core equipment of a nitric acid industrial process system, the device plays an important role in conveying process media, providing power and recovering energy from the system, and the power required by the device is taken from the system, so that the device has outstanding significance in energy conservation and environmental protection. Under the general condition, the nitric acid device energy recovery unit is started to provide steam outside the device, the unit is dragged to the driving working condition by the steam turbine, ignition can be realized after stable operation, and the self-produced steam of the device completely meets the unit dragging after normal production.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an energy recovery unit for a nitric acid device, solve the technical problem of insufficient energy recovery efficiency of the nitric acid device in the prior art and meet the production requirement of the nitric acid device.

In order to solve the technical problems, the invention adopts the following technical scheme:

a nitric acid device energy recovery unit comprises a tail gas turbine, an NOx compressor, a steam turbine, a first gear box and an axial flow compressor, wherein the tail gas turbine comprises a casing and a rotating shaft arranged in the casing, a static blade is arranged on the casing, and a movable blade is arranged on a hub of the rotating shaft;

the tail gas turbine, the NOx compressor, the steam turbine, the first gear box and the axial flow compressor are sequentially and coaxially connected;

5-stage static blades are sequentially arranged on a casing of the tail gas turbine along the axial direction, 5-stage movable blades are sequentially arranged on a rotating shaft along the axial direction, and the static blades and the movable blades are sequentially and alternately arranged.

The 5-stage static blades are respectively a first-stage static blade, a second-stage static blade, a third-stage static blade, a fourth-stage static blade and a fifth-stage static blade; the blade profile parameters at the blade profile uniform diameter position of the 5-stage stationary blade are respectively as follows:

the first-stage stationary blade is 53.0mm in chord length, 35.1mm in blade width, 19.1mm in maximum thickness, 3.5 degrees in inlet geometric angle, 77.8 degrees in outlet geometric angle, 39.8mm in pitch and 10.3mm in throat width;

the second-stage stationary blade is 43.6mm in chord length, 29mm in blade width, 15.4mm in maximum thickness, minus 10.5 degrees in inlet geometric angle, 76.7 degrees in outlet geometric angle, 34.6mm in pitch and 10.1mm in throat width;

the third-stage stationary blade has the chord length of 43.6mm, the blade width of 29.7mm, the maximum thickness of 15.4mm, the inlet geometric angle of-10.9 degrees, the outlet geometric angle of 75.4 degrees, the pitch of 34.6mm and the throat width of 10.6 mm;

the four-stage stationary blade has the chord length of 45.4mm, the blade width of 30.7mm, the maximum thickness of 16.3mm, the inlet geometric angle of-13.4 degrees, the outlet geometric angle of 76.1 degrees, the pitch of 33.4mm and the throat width of 10.5 mm;

the five-stage stationary blade has the chord length of 49.6mm, the blade width of 36.8mm, the maximum thickness of 17.2mm, the inlet geometric angle of-15.3 degrees, the outlet geometric angle of 71.6 degrees, the pitch of 36.0mm and the throat width of 12.8 mm;

the 5-stage movable blades are respectively a first-stage movable blade, a second-stage movable blade, a third-stage movable blade, a fourth-stage movable blade and a fifth-stage movable blade, and the blade profile parameters at the blade profile uniform diameter positions of the 5-stage movable blades are respectively as follows:

the first-stage movable blade has the chord length of 45.5mm, the blade width of 30.2mm, the maximum thickness of 16.4mm, the inlet geometric angle of-11.9 degrees, the outlet geometric angle of 77.7 degrees, the pitch of 36.0mm and the throat width of 9.4 mm;

the chord length of the secondary movable blade is 45.7mm, the blade width is 31.4mm, the maximum thickness is 16.7mm, the inlet geometric angle is-9.7 degrees, the outlet geometric angle is 74.8 degrees, the pitch is 32.8mm, and the throat width is 9.2 mm;

the chord length of the three-stage movable blade is 51.4mm, the blade width is 35mm, the maximum thickness is 16.7mm, the inlet geometric angle is-4.8 degrees, the outlet geometric angle is 74.6 degrees, the pitch is 30.5mm, and the throat width is 7.9 mm;

the four-stage movable blade has the chord length of 59mm, the blade width of 41.2mm, the maximum thickness of 19.2mm, the inlet geometric angle of-1.2 degrees, the outlet geometric angle of 72.7 degrees, the pitch of 34mm and the throat width of 9.4 mm;

the five-stage movable blade has the chord length of 65.5mm, the blade width of 51.4mm, the maximum thickness of 11.5mm, the inlet geometric angle of-11.9 degrees, the outlet geometric angle of 67.2 degrees, the pitch of 37mm and the throat width of 12.5 mm.

The invention also has the following technical characteristics:

the number of the first-stage stator vanes is 56, the number of the second-stage stator vanes is 60, the number of the third-stage stator vanes is 60, the number of the fourth-stage stator vanes is 62, and the number of the fifth-stage stator vanes is 62.

The number of the first-stage movable blades is 62, the number of the second-stage movable blades is 68, the number of the third-stage movable blades is 68, the number of the fourth-stage movable blades is 61, and the number of the fifth-stage movable blades is 56.

The device also comprises a second gear box and a motor which are sequentially connected with the axial flow compressor.

Compared with the prior art, the invention has the following technical effects:

the energy recovery unit of the nitric acid device is high in energy recovery efficiency, and the aim of the invention is to solve the problem of the direction of residual energy after the nitric acid device is used for recovering reaction heat and process medium waste heat and residual pressure to drive the compressor unit. In the scheme, a turbine drags a unit to 95% of the working speed, gradually increases the unit load to the load required by ignition production of a device, checks that the device runs and is ignited after meeting the ignition requirement, and adjusts the unit load to meet the system process requirement; after the device normally produces, the reaction heat produced by the device and the process gas waste heat and residual pressure can be recovered to meet the requirement that the prime motor drives the unit to do work, and abundant mechanical energy is converted into electric energy through the generator to be used for generating electricity.

Drawings

FIG. 1 is a schematic view of the structure of stationary blades, movable blades, meridian flow channels and flow channel mean diameter.

FIG. 2 is a schematic structural diagram of geometric parameters of the airfoil at the mean diameter of the airfoil.

Fig. 3(a) and (b) are total pressure schematics of CFD calculated for the 4-stage version of comparative example 1 and the 5-stage version of comparative example 2.

Fig. 3(c) and (d) are schematic diagrams of the moving blade relative velocity vectors of the 4-stage scheme of comparative example 1 and the 5-stage scheme of comparative example 2 calculated by CFD.

Fig. 4 is a schematic structural view of the upper and lower wall surfaces of a radial flow passage of an exhaust gas turbine according to the present invention.

FIG. 5 is a two-dimensional configuration schematic of the second, third and fourth stage vanes of the present invention.

FIG. 6 is a three-dimensional structural schematic of the second, third and fourth stage vanes of the present invention.

FIG. 7 is a two-dimensional structural schematic of the three, four and five stage buckets of the present invention.

FIG. 8 is a three-dimensional structural schematic of the three, four and five stage buckets of the present invention.

FIG. 9 is a two-dimensional comparison schematic representation of the profiles of the second, third, and fourth stage vanes of the present invention with the second, third, and fourth stage vanes of comparative example 2.

FIG. 10 is a two-dimensional comparison schematic representation of the blade profiles of a three-stage, four-stage, and five-stage bucket of the present invention and a three-stage, four-stage, and five-stage bucket of comparative example 2.

FIG. 11 is a schematic view showing the connection relationship of the energy recovery unit of the nitric acid plant of the present invention.

The meaning of the individual reference symbols in the figures is: 1-a casing, 2-a rotating shaft, 3-a hub, 4-a stationary blade, 5-a movable blade and 6-a flow channel with uniform diameter; 7-tail gas turbine, 8-NOx compressor, 9-steam turbine, 10-first gear box, 11-axial compressor, 12-second gear box and 13-motor;

401-first stage stator blade, 402-second stage stator blade, 403-third stage stator blade, 404-fourth stage stator blade, 405-fifth stage stator blade; 501-a first-stage bucket, 502-a second-stage bucket, 503-a third-stage bucket, 504-a fourth-stage bucket, 505-a fifth-stage bucket.

The present invention will be explained in further detail with reference to examples.

Detailed Description

The energy recovery generator set for the nitric acid production device adopting the double-pressurization method is characterized in that a required process gas is conveyed to the device through an axial flow compressor and an NOx compressor, the reaction heat of a steam turbine recovery device is used, and the tail gas turbine recovers rich energy of nitric acid tail gas and converts the rich energy into mechanical energy to drive a compressor set to do work.

The nitric acid device energy recovery generator set fully utilizes the reaction heat of the device and the residual energy of tail gas after nitric acid absorption reaction, and the surplus mechanical energy is generated through the generator besides the mechanical energy required to be consumed by the unit dragging.

The nitric acid device energy recovery unit consists of a steam turbine, an NOx compressor, a gear box, an axial flow compressor, a tail gas turbine and related auxiliary equipment. The steam source of the steam turbine for driving is the residual energy absorbed by the self-produced steam of the device and the tail gas turbine recovery device, and is used for driving an axial flow compressor and an NOx compressor which provide a process medium for the system. The energy recovery unit conveys the process medium to the device, provides power, and recovers energy from the device at the same time. The invention provides a concept of generating electricity by using waste heat of the byproduct of nitric acid device production.

In the starting process of the unit, the steam turbine is driven by the steam outside the device to finish dragging the unit to 95 percent of the designed rotating speed of the unit, and the process load of the device is gradually adjusted to meet the ignition requirement of the device.

After the nitric acid device is normally produced, the reaction heat is recovered by a waste heat boiler recovery device and is converted into mechanical energy by a steam turbine, and the residual pressure and the waste heat of the process gas are recovered by a tail gas turbine; the invention can effectively recover the reaction heat of nitric acid production and the residual heat and pressure of process gas, and convert the reaction heat and the residual heat and pressure of process gas into mechanical energy to drive the unit to do work. The residual energy is converted into electric energy through a generator, and power generation is realized through internet surfing.

In the present invention, the upper wall surface and the lower wall surface of the radial flow channel are shown in fig. 1, the upper wall surface of the radial flow channel is the casing 1, and the lower wall surface of the radial flow channel is the hub 3. The profile parameters at the profile mean diameter are shown in FIG. 2. In the figure, the chord length is L₁Leaf width of D₁The maximum thickness is d, the inlet geometric angle is alpha, the outlet geometric angle is beta, and the pitch is L₂Throat width of D₂。

In the present invention, CFD refers to computational fluid dynamic analysis. The efficiency of the tail gas turbine is isentropic and is calculated or obtained by adopting a CFD method. The CFD method is a common method known in the art.

The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention.