阅读说明：本技术 一种生物质气化炉内部压力调控系统及其方法 (Internal pressure regulation and control system and method for biomass gasification furnace ) 是由 王凯 于 2020-06-16 设计创作，主要内容包括：本发明公开了一种生物质气化炉内部压力调控系统,涉及生物质气化炉技术领域,包括生物质进料装置、气化炉,气化炉设有生物质进料口,生物质进料装置包括料仓、一级进料螺杆、下料管、关风机以及二级进料螺杆,一级进料螺杆与料仓、下料管连通设置,二级进料螺杆与下料管、生物质进料口连通设置,关风机安装于下料管上,一级进料螺杆对应设置有送料速率调节机构,气化炉对应设置有鼓风/引风调节机构,气化炉对应设置有红外测温模块以及控制模块,红外测温模块设置有温度限值以及升温时间限值,控制模块与送料速率调节机构、鼓风/引风调节机构控制连接,通过对气化炉温度的变化进行监测内部压力变化,进而调控压力以及送料量。(The invention discloses an internal pressure regulation and control system of a biomass gasification furnace, which relates to the technical field of biomass gasification furnaces and comprises a biomass feeding device and a gasification furnace, wherein the gasification furnace is provided with a biomass feed inlet, the biomass feeding device comprises a stock bin, a primary feeding screw rod, a blanking pipe, a blowing machine and a secondary feeding screw rod, the primary feeding screw rod is communicated with the stock bin and the blanking pipe, the secondary feeding screw rod is communicated with the blanking pipe and the biomass feed inlet, the blowing machine is arranged on the blanking pipe, the primary feeding screw rod is correspondingly provided with a feeding speed regulating mechanism, the gasification furnace is correspondingly provided with a blowing/induced air regulating mechanism, the gasification furnace is correspondingly provided with an infrared temperature measuring module and a control module, the infrared temperature measuring module is provided with a temperature limit value and a temperature rise time limit value, the control module, the change of the internal pressure is monitored through the change of the temperature of the gasification furnace, and then the pressure and the feeding amount are regulated and controlled.)

1. An internal pressure regulation and control system of a biomass gasification furnace comprises a biomass feeding device and the gasification furnace (1), wherein the gasification furnace (1) is provided with a biomass feeding hole (7), and is characterized in that the biomass feeding device comprises a storage bin (2), a primary feeding screw (3), a discharging pipe (4), a wind-off machine (5) and a secondary feeding screw (6), wherein the feeding end and the discharging end of the primary feeding screw (3) are respectively communicated with the discharging end of the storage bin (2) and the feeding end of the discharging pipe (4), the feeding end and the discharging end of the secondary feeding screw (6) are respectively communicated with the discharging end of the discharging pipe (4) and the biomass feeding hole (7), and the wind-off machine (5) is arranged on the discharging pipe (4);

the biomass gasification furnace is characterized in that a feeding rate adjusting mechanism is correspondingly arranged on the primary feeding screw (3), a blowing/induced air adjusting mechanism is correspondingly arranged on the gasification furnace (1), an infrared temperature measuring module (8) and a control module electrically connected with the infrared temperature measuring module (8) are correspondingly arranged on the gasification furnace (1), the infrared temperature measuring module (8) is used for measuring the temperature change at the biomass feeding hole (7), the infrared temperature measuring module (8) is provided with a temperature limit value and a temperature rise time limit value, and the control module is in control connection with the feeding rate adjusting mechanism and the blowing/induced air adjusting mechanism.

2. The biomass gasifier internal pressure regulation system of claim 1, wherein the temperature limit is set at 100 ℃.

3. The biomass gasification furnace internal pressure regulation system according to claim 2, wherein the temperature rise time limit is set to 3 s.

4. The biomass gasifier internal pressure regulation system of claim 1, wherein the blower/induced air regulation mechanism comprises a blower, an induced draft fan, a blower opening regulation, and an induced draft fan opening regulation.

5. The internal pressure regulation system of a biomass gasification furnace according to claim 4, wherein the blower opening degree regulating part and the induced draft fan opening degree regulating part are provided as variable frequency motors.

6. The biomass gasifier internal pressure regulation system of claim 5, wherein the feed rate adjustment mechanism is configured as a variable frequency motor.

7. The biomass gasifier internal pressure regulation system according to claim 6, wherein the regulation methods of the blower, the induced draft fan and the primary feed screw (3) are as follows:

when the biomass feeding device is in normal operation, the temperature displayed by the infrared temperature measurement module (8) is higher than the atmospheric temperature and lower than 60 ℃, when the temperature detected by the infrared temperature measurement module (8) is abnormal, the infrared temperature measurement module (8) respectively sends out an electric signal to the air blower, the draught fan and the first-level feeding screw (3), after the electric signal is received, the variable frequency motor works, the opening degree of the air blower is adjusted to 90% of a normal operation value through the variable frequency, the opening degree of the draught fan is adjusted to 110% of the normal operation value through the variable frequency, the opening degree of the first-level feeding screw (3) is adjusted to 80% of the normal operation value through the variable frequency, the operation is continued to wait for the infrared temperature measurement module (8) to detect that the temperature of the biomass feeding hole (7) is recovered to be normal until the temperature is lower than 60 ℃, and after the operation lasts for 10min, the, after the operation lasts for 10min, the induced draft fan is slowly restored to a normal operation state through the variable frequency motor;

when the interval of the two times of infrared temperature measurement is smaller than 24h, manually adjusting the opening of the induced draft fan, and setting the normal operation value of the opening of the induced draft fan to be 105% of the initial setting;

and after the opening degree of the induced draft fan is set to be the maximum value, stopping the furnace for maintenance, wherein the interval of two times of infrared temperature measurement abnormity is still less than 24 h.

Technical Field

The invention relates to the technical field of biomass gasification furnaces, in particular to an internal pressure regulation and control system of a biomass gasification furnace.

Background

The biomass gasification refers to that biomass raw materials (firewood, sawdust, wheat straw, rice straw and the like) are pressed to be molded or simply crushed and processed, then are sent into a gasification furnace, and are gasified and cracked under the condition of lack of oxygen, so that combustible gas is obtained. The principle of biomass gasification is that under certain thermodynamic conditions, the gasification medium (air, oxygen or water vapor, etc.) is used as a gasification mediumThe biomass is subjected to pyrolysis, oxidation, reduction and reforming reactions, and the tar associated with pyrolysis is further subjected to thermal cracking or catalytic cracking to form small molecular hydrocarbon, so that the biomass rich in CO and H is obtained₂And CH₄And the like.

For a continuously produced biomass gasification furnace, the stability of the feeding process is very important, and even the safety of the operation of the gasification system is concerned. According to the pressure difference at the biomass feed inlet, the gasification furnace can be divided into a positive pressure type and a negative pressure type. In the negative pressure type biomass gasification furnace, biomass materials are similarly sucked into the gasification furnace, relatively speaking, the feeding process is more stable, however, in the actual use process, due to the fluctuation of the pressure in the furnace, the pressure is increased steeply caused by the coking of a fluidized bed in the furnace and the like, the feeding hole at a certain moment can be in positive pressure, namely, the combustible gas in the furnace is backflushed to the storage bin through the feeding hole. At the moment, even if the related fan plays a certain role in blocking the backflushing high-temperature gas, if measures cannot be taken in time, the feed inlet is coked and blocked if the measures are not taken, the feed bin is ignited if the measures are not taken, and even major safety accidents occur, so that the problem needs to be solved in the biomass gasification process.

At present, the industrial method for solving the problem mainly comprises the following steps: 1) a differential pressure sensor is arranged in the gasification furnace to monitor the pressure change in the gasification furnace; 2) and a cooling water jacket is additionally arranged on the outer side of the biomass feed inlet. However, both of these solutions have been found to present problems in the actual operation of the gasifier: first, no matter the pressure difference sensor for monitoring the pressure change of the fluidized bed layer or the pressure sensor for monitoring the pressure change of the pipeline, besides a certain detection delay problem, in the fluidized bed type gasification furnace, after being used for a period of time, the sensors are easy to be blocked, and further the judgment of the pressure change is influenced. Secondly, the cooling water jacket outside the biomass feed inlet can only prolong the coking time of the biomass feed inlet, but cannot prevent the coking from occurring, and cannot fundamentally solve the problem, so that the problem is to be improved.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a biomass gasification furnace internal pressure regulation and control system which monitors the change of the temperature of a gasification furnace to find the change of the internal pressure of the gasification furnace and further regulate and control the pressure and the feeding quantity, and the specific scheme is as follows:

an internal pressure regulation and control system of a biomass gasification furnace comprises a biomass feeding device and the gasification furnace, wherein the gasification furnace is provided with a biomass feeding hole, the biomass feeding device comprises a bin, a primary feeding screw rod, a discharging pipe, a wind-off machine and a secondary feeding screw rod, the feeding end and the discharging end of the primary feeding screw rod are respectively communicated with the discharging end of the bin and the feeding end of the discharging pipe, the feeding end and the discharging end of the secondary feeding screw rod are respectively communicated with the discharging end of the discharging pipe and the biomass feeding hole, and the wind-off machine is arranged on the discharging pipe;

the biomass gasification furnace is characterized in that a feeding rate adjusting mechanism is correspondingly arranged on the primary feeding screw, an air blowing/air inducing adjusting mechanism is correspondingly arranged on the gasification furnace, an infrared temperature measuring module and a control module are correspondingly arranged on the gasification furnace, the infrared temperature measuring module is used for measuring the temperature change at the position of the biomass feeding port, the infrared temperature measuring module is provided with a temperature limit value and a temperature rise time limit value, and the control module is in control connection with the feeding rate adjusting mechanism and the air blowing/air inducing adjusting mechanism.

Further, the temperature limit is set to 100 ℃.

Further, the temperature rise time limit is set to 3 s.

Further, the air blowing/air inducing adjusting mechanism comprises an air blower, an induced draft fan, an air blower opening adjusting piece and an induced draft fan opening adjusting piece.

Further, the air blower opening adjusting piece and the draught fan opening adjusting piece are set to be variable frequency motors.

Further, the feeding speed adjusting mechanism is set as a variable frequency motor.

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

(1) when the temperature measured by the infrared temperature measurement module exceeds the temperature limit value within the temperature rise time limit value, the temperature of the outer wall of the gasification furnace at the biomass feed inlet is abnormal, which means that positive pressure occurs at the biomass feed inlet, gasified gas in the gasification furnace backflushs into the storage bin, and meanwhile, the infrared temperature measurement module sends an electric signal which is fed back to the control module to provide basis for regulation and control of the air blowing/air inducing regulation mechanism and the feeding rate regulation mechanism, so that the gasification furnace is controlled to induce air, a micro negative pressure state in the gasification furnace is maintained, a primary feeding screw is controlled to regulate the biomass feed quantity, stable biomass conveying is realized, the gasification furnace stably and safely operates, in sum of all, a pressure difference sensor is not required to be arranged in the gasification furnace, the problems of detection delay and blockage of the pressure sensor are avoided, the defect that coking cannot be prevented but the time for coking at the biomass feed inlet can be prolonged is avoided;

(2) through setting up air-blower, draught fan etc. when gasifier internal pressure is unusual, control air-blower aperture regulating part, draught fan aperture regulating part alright realize regulating and controlling the aperture of air-blower, draught fan, convenient operation, steady operation.

Drawings

Fig. 1 is an overall schematic diagram of an embodiment of the present invention.

Reference numerals: 1. a gasification furnace; 2. a storage bin; 3. a first-stage feed screw; 4. a discharging pipe; 5. shutting off the fan; 6. a secondary feed screw; 7. a biomass feed inlet; 8. and an infrared temperature measurement module.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited to these examples.

As shown in fig. 1, an internal pressure regulation and control system of a biomass gasification furnace, including biomass feeding device and gasification furnace 1, gasification furnace 1 is equipped with biomass feed inlet 7, biomass feeding device includes feed bin 2, one-level feed screw 3, unloading pipe 4, close fan 5 and second grade feed screw 6, the feed end of one-level feed screw 3, the discharge end respectively with the discharge end of feed bin 2, the feed end intercommunication setting of unloading pipe 4, the feed end of second grade feed screw 6, the discharge end respectively with the discharge end of unloading pipe 4, biomass feed inlet 7 intercommunication sets up, close fan 5 and install on unloading pipe 4.

The structure of one-level feeding screw 3 is the same with second grade feeding screw 6, and the height that one-level feeding screw 3 was located is higher than the height that second grade feeding screw 6 was located during the installation, and then unloading pipe 4 is vertical setting in the direction of height.

The living beings are placed in feed bin 2, send into unloading pipe 4 through one-level feed screw 3 in, and the living beings of one-level feed screw 3 fall under the action of gravity through the smooth fan, close fan 5 and rotate according to certain rotational speed, make the living beings material and then fall into second grade feed screw 6, and second grade feed screw 6 is high-speed rotatory, makes the living beings of unloading in closing fan 5 get into gasifier 1 through living beings feed inlet 7 fast.

The gasifier 1 is correspondingly provided with an infrared temperature measurement module 8 and a control module, the infrared temperature measurement module 8 is used for measuring the temperature change at the biomass feed inlet 7, an infrared ray thermometer is adopted, the position of the infrared temperature measurement module is arranged at a certain distance from the secondary feed screw 6 to the biomass feed inlet 7 of the gasifier 1, and the distance is comprehensively determined according to the actual position, the angle and a plurality of test results.

The infrared temperature measurement module 8 is provided with a temperature limit value and a temperature rise time limit value, and for a long time, according to experience summary of operation of the biomass gasification furnace 1, it is found that when transient positive pressure occurs in the gasification furnace 1, the outer wall of the biomass feed port 7 can be rapidly heated to more than 100 ℃ in a short time (generally less than 3s), therefore, in the embodiment, the temperature limit value is set to 100 ℃, the temperature rise time limit value is set to 3s, when the infrared temperature measurement module 8 monitors that the temperature of the outer wall at the biomass feed port 7 is rapidly heated to more than 100 ℃ in 3s, at this time, it represents that the pressure in the gasification furnace 1 is abnormal, which means that the positive pressure occurs in the biomass feed port 7, and gasified gas in the gasification.

In order to facilitate the regulation and control of parameters by operators, the control module is in signal connection with the infrared temperature measurement module 8, the control module receives an electric signal sent by the infrared temperature measurement module 8 and processes the electric signal, the control module can adopt a PLC (programmable logic controller), and the infrared temperature measurement module 8 is electrically connected with the input end of the control module. The primary feeding screw 3 is correspondingly provided with a feeding rate adjusting mechanism, the gasification furnace 1 is correspondingly provided with an air blowing/air inducing adjusting mechanism, the control module is in control connection with the feeding rate adjusting mechanism and the air blowing/air inducing adjusting mechanism, and when positive pressure occurs at the biomass feeding hole 7, the feeding amount and the pressure in the gasification furnace 1 are adjusted by controlling the feeding rate adjusting mechanism and the air blowing/air inducing adjusting mechanism.

Specifically, the air blowing/air inducing adjusting mechanism comprises an air blower, an induced draft fan, an air blower opening adjusting piece and an induced draft fan opening adjusting piece. The opening adjusting piece of the air blower and the opening adjusting piece of the draught fan are set to be variable frequency motors, the feeding speed adjusting mechanism is set to be a variable frequency motor, and the output end of the control module is electrically connected with the variable frequency motor. In fact, when positive pressure occurs in the gasification furnace 1, the biomass feeding amount can be regulated and controlled by changing the frequency of the feeding rate regulating mechanism, and the pressure in the gasification furnace 1 can be balanced by changing the frequency of the opening regulating part of the air blower and the opening regulating part of the induced draft fan, so that the gasification furnace is maintained in a micro-negative pressure state, and the biomass is ensured to be sucked into the gasification furnace 1.

Specifically, the method for regulating and controlling the air blower, the induced draft fan and the primary feed screw 3 of the gasification furnace 1 by the infrared temperature measurement module 8 is as follows:

(1) during normal operation, the temperature displayed by the infrared temperature measurement module 8 is slightly higher than the atmospheric temperature and lower than 60 ℃. When the temperature detected by the infrared temperature measurement module 8 is abnormal, namely higher than 60 ℃, even within 3s, the temperature is rapidly raised to more than 100 ℃, the infrared temperature measurement module 8 respectively sends out electric signals to the air blower, the induced draft fan and the first-stage feeding screw 3, after receiving the electric signals, the variable frequency motor works, the opening degree of the air blower is adjusted to 90% of the normal operation value through the variable frequency, the opening degree of the induced draft fan is adjusted to 110% of the normal operation value through the variable frequency, and the opening degree of the first-stage feeding screw 3 is adjusted to 80% of the normal operation value through the variable frequency. And continuously running, waiting for the temperature of the biomass feed inlet 7 to be recovered to be normal by the infrared temperature measurement module 8 until the temperature is lower than 60 ℃, continuing for 10min, slowly recovering the air blower and the first-stage feed screw 3 to be in a normal running state through the variable frequency motor, and slowly recovering the induced draft fan to be in a normal running state through the variable frequency motor after continuing for 10 min.

(2) And if the interval of the two times of infrared temperature measurement is less than 24h, manually adjusting the opening of the induced draft fan, and setting the normal operation value of the opening of the induced draft fan to be 105% of the initial setting.

(3) When the opening degree of the induced draft fan is set to be the maximum value, the interval of two times of infrared temperature measurement abnormity is still less than 24 hours, and the condition that the pipeline of the gasification furnace 1 is blocked needs to be shut down for maintenance and the blocked point is cleaned.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.