阅读说明：本技术 一种大颗粒煤焦燃烧特性测试系统 (Large-particle coke combustion characteristic testing system ) 是由 张松松 董勇 翟明 齐国利 邬爱国 于 2020-04-22 设计创作，主要内容包括：本发明公开了一种大颗粒煤焦燃烧特性测试系统,属于实验设备技术领域。该测试系统包括炉体和支撑炉体的支架；还包括工作台、升降装置、水冷装置和进气均风装置；通过将炉体分为三段加热区,上段加热区与下段加热区最高加热温度为1350℃,中间段加热区的最高加热温度为1600℃,可实际模拟层燃锅炉大颗粒燃烧高温需求。并通过采用双导轨升降平台控制燃料的升降速率与升降高度,以模拟层燃锅炉燃料入炉后升温、燃烧、燃尽的过程。本发明公开的测试系统能有效解决目前采用热重分析仪研究煤焦反应特性存在的技术问题,为优化层燃锅炉燃烧提供理论支撑,适于推广与应用。(The invention discloses a large-particle coal tar combustion characteristic testing system, and belongs to the technical field of experimental equipment. The test system comprises a furnace body and a bracket for supporting the furnace body; the air conditioner also comprises a workbench, a lifting device, a water cooling device and an air inlet and equalizing device; the furnace body is divided into three sections of heating zones, the highest heating temperature of the upper section of heating zone and the lower section of heating zone is 1350 ℃, the highest heating temperature of the middle section of heating zone is 1600 ℃, and the requirement of large-particle combustion high temperature of a grate-fired boiler can be simulated actually. And the lifting speed and the lifting height of the fuel are controlled by adopting the double-guide-rail lifting platform, so that the processes of heating, burning and burnout of the fuel of the grate-fired boiler after entering the boiler are simulated. The test system disclosed by the invention can effectively solve the technical problem existing in the research on the coal coke reaction characteristics by adopting the thermogravimetric analyzer at present, provides theoretical support for optimizing the combustion of the grate-fired boiler, and is suitable for popularization and application.)

1. A large-particle coal tar combustion characteristic testing system comprises: the furnace body and a bracket for supporting the furnace body; it is characterized by also comprising: the air inlet and air outlet device comprises a workbench, a lifting device, a water cooling device and an air inlet and air equalizing device;

the workbench is arranged on the bracket and is provided with a PID temperature control instrument and a switch device;

the furnace body consists of a heat-insulating layer, a furnace lining and a hearth from outside to inside in sequence; the furnace body is divided into three sections of heating zones, a heating rod and a thermocouple are arranged in each heating zone, and the heating rod and the thermocouple are respectively and electrically connected with the PID temperature control instrument;

the lifting device is positioned at the top end of the furnace body and comprises a double-guide-rail lifting platform, a lower hanging balance and a material loading device; the lower hanging type balance is placed on a supporting plate of the double-guide-rail lifting platform and is connected with the material loading device through a platinum wire;

the top end of the furnace body is provided with a cavity, and the top end of the cavity is provided with a heat-resistant stainless steel plate with holes for sealing the cavity; the water cooling device is coiled on the outer wall of the cavity and comprises a water inlet connecting pipe and a water outlet connecting pipe which are arranged outside the wall of the cavity; the air inlet and air distribution device comprises a porous air distribution net, an air inlet pipe orifice and an exhaust outlet which are arranged outside the cavity wall.

2. The large particle char combustion characteristic testing system according to claim 1, further comprising a sight hole; the observation hole is arranged on the outer wall of the furnace body and used for observing the combustion condition of the fuel in the hearth and macroscopically analyzing the influence of the change of the temperature and the combustion atmosphere on the combustion of the fuel.

3. The large-particle coke combustion characteristic testing system according to claim 1, wherein three heating rods uniformly arranged at 120 ° are arranged in the heating zone, and the heating rods are U-shaped silicon carbide rods.

4. The large particle coal tar combustion characteristic testing system according to claim 3, wherein the thermocouple is a platinum thermocouple, and the thermocouples are uniformly arranged in the heating zone.

5. The large-particle coal tar combustion characteristic testing system according to claim 1, wherein the loading device is a platinum basket or a platinum crucible, and the loading device, the downward hanging type balance and the hearth are on the same axis.

6. The large-particle coal tar combustion characteristic testing system according to claim 1, wherein the porous air-equalizing net is arranged inside the cavity and abuts against the hearth.

7. The large-particle coke burning characteristic testing system according to claim 1, wherein two ends of the furnace lining are respectively provided with a blocking plate, and the blocking plates are abutted to the furnace body.

8. The large particle coal tar combustion characteristic testing system according to claim 1, wherein the heating zone is heated by the heating rod, and the heating temperature and the heating rate are controlled by the PID temperature control instrument program; wherein the heating rod, the PID temperature control instrument respectively with switching device electric connection.

9. The large particle coal tar combustion characteristic testing system of claim 8, wherein the maximum heating temperature of the heating zone is 1600 ℃, and the heating rate of the heating zone is 15 ℃/min to 20 ℃/min.

Technical Field

The invention belongs to the technical field of experimental equipment, relates to an experimental device for researching coal tar combustion reaction characteristics, and particularly relates to a large-particle coal tar combustion characteristic testing system.

Background

The number of industrial boilers in China is large, the number of the common industrial boilers in China is about 39 thousands by 2018, the number of the coal-fired chain boilers in the industrial boilers is huge, the number of the coal-fired chain boilers is nearly 30 thousands by the literature in 2010, along with implementation of implementation schemes of energy-saving and environment-friendly comprehensive lifting engineering of the coal-fired boiler and coal-to-gas engineering, the number of the gas boilers is increased and part of small chain boilers are dismantled, but the number of the existing chain boilers still occupies an important proportion in the industrial boilers. The layered combustion boiler in China mainly has small capacity, has the characteristics of large coal variety change, low quality, high regional strength and low-altitude emission, generally has the phenomenon of low combustion efficiency and the like, but because of the energy structure of 'oil shortage, gas shortage and coal richness' in China, the internal combustion coal industrial boiler still exists for a long time, and plays an important role in industrial production and civil heating in China.

The coal for the layer combustion coal-fired boiler has larger granularity, and the largest coal can burn coal particles with the particle size of 30-40mm, but the layer combustion boiler generally has the problems of higher carbon content in ash slag and the like due to the influences of the effective diffusion coefficient of the ash layer, the reduction of the reaction characteristic of coke and the like in the combustion process of large particles. Most of the research on the coal coke combustion reaction characteristics is carried out by thermogravimetric instrument analysis at present, but the particle weight of the thermogravimetric analyzer is about 2mg at most generally, and the particle weight is influenced by the heating rate (generally less than 50 ℃/min) and the highest temperature (generally 1200 ℃), so that the large-particle coal coke reaction characteristics cannot be directly reflected.

Therefore, it is an urgent problem to those skilled in the art to develop a test system capable of measuring the combustion reaction characteristics of large-particle coke.

Disclosure of Invention

In view of this, the present invention provides a system for testing combustion characteristics of large-particle char, which aims to solve the problems in the prior art.

In order to achieve the above purpose, the invention provides the following technical scheme:

a large-particle coal tar combustion characteristic testing system comprises: the furnace body and a bracket for supporting the furnace body; further comprising: the air inlet and air outlet device comprises a workbench, a lifting device, a water cooling device and an air inlet and air equalizing device;

the workbench is arranged on the bracket and is provided with a PID temperature control instrument and a switch device;

the furnace body consists of a heat-insulating layer, a furnace lining and a hearth from outside to inside in sequence; the furnace body is divided into three sections of heating zones, a heating rod and a thermocouple are arranged in each heating zone, and the heating rod and the thermocouple are respectively and electrically connected with the PID temperature control instrument;

the lifting device is positioned at the top end of the furnace body and comprises a double-guide-rail lifting platform, a lower hanging balance and a material loading device; the lower hanging type balance is placed on a supporting plate of the double-guide-rail lifting platform and is connected with the material loading device through a platinum wire;

the top end of the furnace body is provided with a cavity, and the top end of the cavity is provided with a heat-resistant stainless steel plate with holes for sealing the cavity; the water cooling device is coiled on the outer wall of the cavity and comprises a water inlet connecting pipe and a water outlet connecting pipe which are arranged outside the wall of the cavity; the air inlet and air distribution device comprises a porous air distribution net, an air inlet pipe orifice and an exhaust outlet which are arranged outside the cavity wall.

The furnace body is divided into three sections of heating zones, the hearth is a corundum-mullite tube, the highest heating temperature of the upper section of heating zone and the lower section of heating zone is 1350 ℃, the highest heating temperature of the middle section of heating zone is 1600 ℃, and the requirement of large-particle combustion high temperature of a grate-fired boiler can be simulated actually. And the three heating zones are controlled in a temperature partition mode, the heating temperature can be set independently, and the temperature field gradient (0-terminal temperature) in the furnace can be realized by the heating terminal temperatures in different settings.

It should be noted that most of the existing research on coal coke reaction characteristics is thermogravimetric instrument analysis, but the maximum particle weight of the thermogravimetric analyzer is about 2mg, and the large particle coal coke combustion reaction characteristics cannot be directly reflected; the heating rate of the particles of the grate-fired boiler is high, while the heating rate of the thermogravimetric analyzer is generally less than 50 ℃/min, and the heating rate has certain deviation with the actual coal coking process; and the coal coke combustion reaction characteristic is greatly influenced by temperature, the maximum temperature of the current thermogravimetric analysis instrument is generally 1200 ℃, and the difference between the maximum temperature and the typical combustion temperature of a grate-fired boiler is 1350 ℃, and even the actual higher combustion temperature exists. Therefore, the significance of providing the test system capable of measuring the combustion reaction characteristics of the large-particle coal coke is great.

In addition, the quantity of the layer combustion boilers in the coal-fired industry of China is large, and due to the characteristics of relatively large fuel particle size and the like of the layer combustion boilers, the problems of high carbon content of ash and slag and the like generally exist. The test system disclosed by the invention can analyze the combustion reaction characteristics of large-particle coal coke and the pollutant emission generation rule, can also analyze the difference of the combustion characteristics of different coal types, and provides theoretical support for optimizing the combustion of a grate firing boiler so as to realize low pollutant emission considering energy efficiency.

Further, the large-particle coal tar combustion characteristic testing system also comprises an observation hole; the observation hole is arranged on the outer wall of the furnace body and used for observing the combustion condition of the fuel in the hearth and macroscopically analyzing the influence of the change of the temperature and the combustion atmosphere on the combustion of the fuel.

It is worth to say that the observation hole is split, and one side is phi 20mm round hole, and one side is 200mm high, 20mm wide rectangular hole. And the observation hole is provided with high-temperature-resistant quartz glass and a high-temperature-resistant sealing strip, so that the state of the fuel during combustion can be directly observed while the airtightness of the furnace body is ensured, and the influence of the fuel on the combustion along with the temperature change and the combustion atmosphere change can be macroscopically analyzed.

Preferably, three heating rods which are uniformly arranged at 120 degrees are arranged in the heating zone, and the heating rods are U-shaped silicon carbide rods.

Preferably, the thermocouple is a platinum thermocouple, and the thermocouples are uniformly distributed in the heating zone.

Furthermore, the three heating zones of the furnace body adopt a respective heating mode, the upper heating zone and the lower heating zone are respectively provided with three U-shaped silicon-carbon rods, the middle heating zone is provided with three U-shaped right-angle silicon-molybdenum rods for heating, each layer of U-shaped heating rods is uniformly arranged at 120 degrees, the heating rods in each heating zone are connected with the intelligent temperature control instrument, and the heating rods are communicated with the intelligent temperature control instrument through software, so that the establishment of a heating program and the storage of temperature data in the heating process are realized. Wherein, the intelligent temperature control instrument not only can realize the establishment of different heating rate, heating time, dwell time isoparametric to keep warm at terminal temperature, can also realize burning contrastive analysis under the different heating condition.

Furthermore, the upper section heating zone and the lower section heating zone are respectively provided with three B-index platinum thermocouples, the middle section heating zone is provided with three S-index platinum thermocouples, and the three thermocouples are respectively and averagely arranged in each section heating zone. And the thermocouple signal in the middle of each section of heating zone is fed back to the heating rod temperature controller, the start and stop of the heating rod and the heating rate are controlled by the temperature controller, and the temperature in the furnace body is kept unchanged.

Preferably, the material loading device is a platinum material basket or a platinum crucible, and the material loading device, the downward hanging type balance and the hearth are positioned on the same axis.

It should be noted that the invention adopts a double-guide rail lifting platform, a lower hanging type balance can be placed on a platform supporting plate, the balance can lift along with the supporting plate, and the double-guide rail lifting platform is communicated with control software and can be used for setting and controlling the lifting speed and the lifting height. The range of the vertical lifting range of the double-guide-rail lifting platform is 0-1610 mm, the maximum load is 50kg, and the lifting speed is adjustable within the range of 0-400 mm/s.

Furthermore, the double-track lifting is adopted in the invention to ensure the stability of the platform in the lifting process and reduce the influence on the balance shaking.

Furthermore, the material carrying device is woven or cast by platinum wires with the purity of 99.9 percent so as to meet the requirement of smaller extension degree at the temperature of 1600 ℃, is connected with a lower hanging type balance through the platinum wires, and sets the lifting speed of the platform according to the gradient of the temperature field in the boiler so as to simulate the processes of temperature rise, combustion and burnout of the fuel of the grate-fired boiler after entering the boiler, realize the high lifting speed conforming to the actual condition and simulate the process of grate-fired combustion.

It should be noted that the distance that the sample basket moves, i.e. the distance from the outside of the furnace (the position of the environmental temperature measuring point) to the highest point of the temperature in the furnace, is longitudinally calibrated by the thermocouple, the temperature of the multipoint is calculated, and then the lifting rate is set according to the high temperature rise rate (e.g. 200 ℃/min).

In addition, the balance adopts a downward hook type, the maximum measuring range is 220g, the precision is one thousandth, and the automatic storage function of the balance can set data reading frequency (1 group/s) and transmit the real-time reading and the corresponding time to a computer to draw a curve so as to calculate the characteristic parameters of the large-particle coal tar TG and DTG.

Preferably, the porous air-equalizing net is arranged inside the cavity, and the porous air-equalizing net is abutted to the hearth.

Preferably, two ends of the furnace lining are respectively provided with a plugging plate, and the plugging plates are abutted to the furnace body.

Preferably, the heating zone is heated by the heating rod, and the heating temperature and the heating rate are controlled by the program of the PID temperature control instrument; wherein the heating rod, the PID temperature control instrument respectively with switching device electric connection.

Further preferably, the highest heating temperature of the heating zone is 1600 ℃, and the heating rate of the heating zone is 15 ℃/min to 20 ℃/min.

It is worth explaining that the three sections of heating zones in the furnace body are heated by adopting silicon controlled PID (proportion integration differentiation) continuous regulation and 50 sections of intelligent instrument programs to control the temperature, wherein the highest heating rate of 0-1350 ℃ can realize 20 ℃/min, and the highest heating rate of 1350-1600 ℃ can realize 15 ℃/min.

If the temperature in the furnace rises to 1600 ℃, the sample is sent into the furnace from the outside of the furnace through the lifting mechanism, the temperature field (the ambient temperature is 1600 ℃ at the maximum) can be measured through the thermocouple, and the temperature rising characteristic of the fuel entering the furnace of the grate-fired furnace is simulated according to the set lifting speed of the lifter.

Compared with the prior art, the invention discloses a large-particle coal tar combustion characteristic testing system, which has the advantages that:

the three-section dimensional large-particle coke combustion characteristic testing system disclosed by the invention can effectively solve the technical problem existing in the research of coke reaction characteristics at present, can simulate the complete process from the heating of layer-combustion boiler fuel from normal temperature to the combustion, truly reflects the large-particle coke combustion characteristics, researches the influence of different temperatures, different residence times and different combustion atmospheres on the large-particle coke combustion reaction rate and the combustion pollutant emission, and analyzes the characteristic parameters of large-particle coke initial reaction temperature, ignition temperature, coke reaction rate and the like and the emission rule of pollutants such as NOx and the like. This application can reduce the discharge of layer burning ash and slag carbonaceous content, reduction fuel burning pollutant for through the experiment and provide the data support, adjust for optimizing layer burning boiler combustion and provide the theoretical foundation to realize the low pollutant discharge of layer burning boiler collaborative energy efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a large-particle char combustion characteristic testing system according to the present invention.

FIG. 2 is a cross-sectional view of a large particle char combustion characteristic testing system of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the specification, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention discloses a test system capable of measuring large-particle coal tar combustion reaction characteristics, which specifically comprises the following components: a furnace body 1 and a bracket 2 for supporting the furnace body 1; further comprising: the working table 3, the lifting device, the water cooling device and the air inlet and air equalizing device;

the workbench 3 is arranged on the bracket 2, and the workbench 3 is provided with a PID temperature control instrument 4 and a switch device 5;

the furnace body 1 consists of an insulating layer 6, a furnace lining 7 and a hearth 18 from outside to inside in sequence; the furnace body 1 is divided into three sections of heating zones, a heating rod 8 and a thermocouple are arranged in each heating zone, and the heating rod 8 and the thermocouple are respectively and electrically connected with the PID temperature control instrument 4;

the lifting device is positioned at the top end of the furnace body 1 and comprises a double-guide-rail lifting platform 9, a lower hanging balance 10 and a loading device 11; the lower hanging type balance 10 is placed on a supporting plate of the double-guide-rail lifting platform 9, and the lower hanging type balance 10 is connected with the material loading device 11 through a platinum wire;

the top end of the furnace body 1 is provided with a cavity 12, and the top end of the cavity 12 is provided with a heat-resistant stainless steel plate with holes 13 for sealing the cavity; the water cooling device is coiled on the outer wall of the cavity 12 and comprises a water inlet connecting pipe 14 and a water outlet connecting pipe 15 which are arranged outside the wall of the cavity 12; the air inlet and air distribution device comprises a porous air distribution net 16, an air inlet pipe orifice and an exhaust outlet which are arranged outside the wall of the cavity 12.

The gas inlet pipe orifice is connected with a gas pipeline 22, a valve 20 and a flowmeter are arranged on the gas pipeline 22, and one end of the gas pipeline 22 is connected with a steel cylinder 21 filled with gas; the steel cylinder 21 is filled with N according to the experiment requirement₂；

The bottom of the furnace body 1 is also connected with a gas pipeline 22, a valve 20 and a flowmeter are arranged on the gas pipeline 22, and one end of the gas pipeline 22 is connected with a steel cylinder 21 filled with gas; the cylinder 23 is filled with a reaction gas according to the experimental requirements.

Further, the large-particle coal tar combustion characteristic testing system further comprises an observation hole 17; the observation hole 17 is arranged on the outer wall of the furnace body 1, and the observation hole 17 is used for observing the combustion condition of the fuel in the hearth 18 and macroscopically analyzing the influence of the change of the temperature and the combustion atmosphere on the combustion of the fuel.

Exemplarily, three heating rods 8 uniformly arranged at 120 degrees are arranged in the heating zone, and the heating rods 8 are U-shaped silicon carbide rods. And the thermocouples are platinum thermocouples which are uniformly arranged in the heating zone.

Further, the loading device 11 is a platinum basket or a platinum crucible, and the loading device 11, the hanging balance 10 and the furnace 18 are arranged on the same axis.

Further, the porous air-equalizing net 16 is arranged inside the cavity 12, and the porous air-equalizing net 16 is abutted to the hearth 18.

Furthermore, the two ends of the furnace lining 7 are respectively provided with a plugging plate 19, and the plugging plates 19 are abutted against the furnace body 1.

Further, the heating zone is heated by a heating rod 8, and the heating temperature and the heating rate are controlled by a program of a PID temperature control instrument 4; wherein the heating rod 8 and the PID temperature control instrument 4 are respectively electrically connected with the switch device 5.

Furthermore, the highest heating temperature of the heating zone is 1600 ℃, and the heating rate of the heating zone is 15 ℃/min to 20 ℃/min.

In order to further describe the technical scheme disclosed by the invention application and verify the technical effect achieved by the technical scheme, the inventor carries out the following experiments:

the invention discloses a large-particle coal tar combustion characteristic testing system, which has the following specific operation and working principles:

1. constant temperature test method:

(1) the temperature in the furnace rises to a set temperature (the highest temperature is 1600 ℃), measuring the temperatures of different points from the ambient temperature to the highest temperature point along the longitudinal direction by a thermocouple, and drawing a temperature field;

(2) according to the gradient and the longitudinal length of the temperature field (the longitudinal distance from the environmental temperature stop point to the highest temperature stop point of the sample), calculating the descending rate of the lifting platform to simulate the characteristic analysis of the actual rising temperature rate of the fuel of the layer combustion boiler, and calculating the lifting rate to simulate the characteristic analysis of the actual cooling rate of the fuel of the layer combustion boiler; wherein, the upper part of the test bed is provided with a staying chamber, and when the sample is lifted to the staying chamber after the test is finished, nitrogen can be introduced to cool the fuel;

(3) large granular coal coke is put into a platinum hanging basket which is connected with a lifting platform through a platinum wireThe lower hanging type balances are connected, reaction gas is introduced, the descending speed of the lifting platform is set through software, so that the coal coke is rapidly moved from an environment temperature stop point to a target temperature measuring point, and a fuel combustion process of the simulated grate-fired furnace is stopped at the target temperature measuring point; after the coal coke is burnt for a certain time, setting a lifting rate to move the coal coke from a target temperature to a staying chamber to simulate the burnout process of the layer combustion fuel, and introducing N when a sample reaches the staying chamber₂Reducing the temperature of the coal tar sample to ambient temperature;

(4) when the temperature of the coal coke is reduced to the environmental temperature, analyzing the carbon content of the burnt coal coke, and simulating and calculating the burnout rate of the large-particle coal coke;

(5) the software is used for reading and storing the scale readings in real time, and large-particle coal tar TG and DTG curves can be calculated in a sectional mode.

2. Temperature rise test method

(1) Putting large granular coal coke into platinum cradle, connecting platinum cradle with lifting platform via platinum wire by hanging balance, introducing reaction gas (O)₂And N₂In which O is₂Concentration and ventilation flow rate are adjustable), a sample is directly sent to a target position (thermocouple measuring points, temperature of the measuring points can be directly read and stored) through software, the heating rate is set to be heated from the ambient temperature to the target temperature (the maximum temperature is 1600 ℃), and the temperature of the target position is read and stored in real time by computer temperature control software in the temperature rising process;

(2) the scale reading is read and stored in real time by computer software, TG and DTG curves of the coal coke at different temperature points can be calculated, and the combustion reaction characteristics of the coal coke are analyzed;

(3) the temperature of a measuring point of the observation hole can be measured by the thermocouple, the coal tar sample can be sent to the position of the observation hole, and the combustion state of the coal tar sample is observed by the high-speed camera and the infrared camera.

In conclusion, the invention can simulate the actual fuel drying and volatilization analysis of the grate-fired boiler to obtain the combustion process and the burnout process in the constant temperature test method, and the sample is put into the hanging basket woven by platinum wires to ensure the sufficient contact between the reaction gas and the sample coke.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.