Control method for realizing waste heat recovery of circular cooler

Abstract

The invention provides a control method for realizing waste heat recovery of a circular cooler, which comprises the following steps of: calculating cooling air quantity required by a high-temperature section according to a waste gas temperature set value of the high-temperature section, a heat calculation value of a sintered ore block at a 1 # monitoring point and a heat calculation value of the sintered ore block at a 2 # monitoring point; according to the heat calculation value of the sintered ore blocks at the 2 # monitoring point and the set average ore temperature and the heat set value of the sintered ore blocks at the 3 # monitoring point, the cooling air volume needed by the medium-temperature section is calculated; and according to the heat calculation value of the sinter blocks at the 3 # monitoring point and the set average ore temperature and the heat set value of the sinter blocks at the 4 # monitoring point, the cooling air volume required by the low-temperature section is calculated. According to the control method disclosed by the invention, the waste heat of the high-temperature section is utilized for power generation, the normal cooling effect of the sinter in the medium-temperature section and the low-temperature section is realized, parameter guidance is provided for cooling air volume adjustment of each temperature section, and the triple purposes of controllable sinter cooling, waste heat power generation and variable-frequency power saving are realized.

Description

Technical Field

[0001] This invention relates to the field of annular cooler control technology, and specifically to a control method for realizing waste heat recovery from annular coolers. Background Technology

[0002] Sintering is a fundamental step in the steel industry, providing high-quality raw materials for ironmaking. The sintering process involves batching and mixing iron-containing raw materials, then roasting them at high temperatures (≤1400℃) in a sintering machine, causing a series of physicochemical changes in the materials. Cooling in the sintering process is achieved by an annular cooler, which mainly consists of a feed chute, a trolley, a bellows, and a discharge chute. Its function is to cool the hot ore unloaded from the sintering machine by blowing or drawing air. The cooling effect is related to the thickness and uniformity of the hot ore layer; with the same airflow, a thinner layer of hot ore on the trolley is easier to cool.

[0003] A ring cooler is typically divided into three temperature zones: a high-temperature zone, a medium-temperature zone, and a low-temperature zone. The cooling process of the ring cooler is expected to be controllable, so that the sinter in each zone is kept within a suitable temperature range, and the material temperature at the outlet reaches the set outlet temperature.

[0004] Currently, to achieve the cooling effect of sinter, the dampers are usually fully open and the variable frequency fans are also running at high frequencies. This leads to the waste heat power generation being affected by flue gas temperature fluctuations, resulting in low efficiency. At the same time, the cooling process inside the annular cooler is uncontrollable, and the subsequent cooling effect can only be estimated manually based on the ore temperature at the outlet of the annular cooler. This often results in the ore outlet temperature being too high, burning the conveyor belt, or requiring water cooling, which reduces the quality of the sinter.

[0005] In summary, there is an urgent need for a control method to realize the recovery of waste heat from the annular cooler in order to solve the problems existing in the current technology. Summary of the Invention

[0006] The purpose of this invention is to provide a control method for recovering waste heat from an annular cooler, aiming to solve the problems of large flue gas temperature fluctuations and uncontrollable cooling of sinter inside the annular cooler in existing waste heat power generation technologies. The specific technical solution is as follows: A control method for waste heat recovery in an annular cooler, wherein monitoring points 1#, 2#, 3#, and 4# are sequentially set at the high-temperature section inlet, the junction of the medium-high temperature section, the junction of the medium-low temperature section, and the low-temperature section outlet of the annular cooler. The control method includes: Based on the exhaust gas temperature setpoint in the high-temperature section Calculated heat value of sintered ore block at monitoring point #1 And the calculated heat value of the sintered ore block at monitoring point #2 Calculate the required cooling air volume for the high-temperature section. ; Based on the heat calculation value of the sintered ore block at monitoring point #2 The set average ore temperature at monitoring point #3 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the mid-temperature range. ; Based on the heat calculation value of the sintered ore block at monitoring point #3 The set average ore temperature at monitoring point #4 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the low-temperature section. .

[0007] Preferably, adopt If any one of monitoring points 1#, 2#, 3#, and 4# is used, then the sintered ore is divided into blocks at that monitoring point. Calculated heat value at the location Represented as: in, For monitoring points The quality of the sintered ore blocks. The specific heat capacity of the sintered ore blocks For monitoring points The average temperature of the sintered ore blocks The density of the sinter. The inner radius of the sinter block is given. The outer radius of the sinter block. The operating angular velocity of the annular cooler. For monitoring points The average height of the sintered ore blocks Pi The time interval for dividing sintered ore.

[0008] Preferably, the average ore temperature at monitoring point #1 Equal to the average surface temperature measurement of the sintered ore block at monitoring point #1 ; The average mine temperature at monitoring points #2, #3, and #4 is expressed as follows: use This refers to any one of monitoring points #2, #3, or #4. Average ore temperature of sintered ore blocks Represented as: in, This indicates that the sintered ore is divided into blocks at the monitoring point. The average surface temperature measurement at that location, Indicates monitoring point The cooling gradient at that point, Indicates monitoring point The average height of the sintered ore blocks; Or, adopt This refers to any one of monitoring points #2, #3, or #4. Average ore temperature of sintered ore blocks Represented as: Set the scaling factor monitoring points The sintered ore at the location is divided into upper and lower layers, with the upper layer denoted as... The lower-level block representation is as follows ,in, , Indicates monitoring point The average height of the sintered ore blocks; Divide the upper layer into equal parts along the height direction. Each sub-layer has a sum of its mineral temperature. Represented as: Divide the lower layer into equal sections along the height direction. Each sub-layer has a sum of its mineral temperature. Represented as: Then monitoring point Average ore temperature of sintered ore blocks Represented as: in, and All are segmentation step sizes. This indicates that the sintered ore is divided into blocks at the monitoring point. The average surface temperature measurement at that location, The coefficient is related to the particle size coefficient. This is the material constant. Indicates the wind speed of the cooling air. for The temperature of the ore at an altitude.

[0009] Preferably, the required cooling air volume for the high-temperature section Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. This refers to the temperature of the cooling air input to the high-temperature section. This refers to the utilization rate of heat.

[0010] Preferably, the exhaust gas temperature setpoint is based on the high-temperature section. With exhaust gas temperature measurement value The difference between them is used as feedback to adjust the cooling air volume required for the high-temperature section. Specifically: in, This is the proportionality coefficient.

[0011] Preferably, the exhaust gas temperature in the high-temperature section is: The amount of electricity generated per unit time is expressed as: in, This refers to the cooling airflow input to the high-temperature section. The density of the exhaust gas, The specific heat capacity of the exhaust gas. The outlet temperature is the temperature of the exhaust gas after heating the steam in the high-temperature section during power generation. For power generation efficiency, This refers to the amount of electricity generated per unit of time.

[0012] Preferably, the required cooling air volume for the intermediate temperature range Represented as: Among them, the exhaust gas temperature setpoint in the medium temperature section Represented as: Heat setpoint of sintered ore block at monitoring point #3 Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. For heat utilization rate, This refers to the temperature of the cooling air input to the mid-temperature section. The average temperature of the sintered ore block at monitoring point #2. The set average ore temperature for the sintered ore blocks at monitoring point #3. This is the proportionality coefficient. The average height of the sintered ore block at monitoring point #3. The quality of the sintered ore blocks at monitoring point #3.

[0013] Preferably, the average ore temperature at monitoring point #3 is set according to the sintered ore blocks. and actual average ore temperature Feedback adjustment obtains the required cooling air volume for the mid-temperature range. , represented as: in, This is the proportionality coefficient.

[0014] Preferably, the required cooling air volume for the low-temperature section Represented as: Among them, the exhaust gas temperature setpoint in the low-temperature section Represented as: Heat setpoint of sintered ore block at monitoring point #4 Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. For heat utilization rate, This refers to the temperature of the cooling air input to the low-temperature section. The average temperature of the sintered ore block at monitoring point #3. The set average ore temperature for the sintered ore blocks at monitoring point #4. This is the proportionality coefficient. The average height of the sintered ore block at monitoring point #4. The quality of the sintered ore blocks at monitoring point #4.

[0015] Preferably, the average ore temperature at monitoring point #4 is set according to the sintered ore block. and actual average ore temperature Feedback adjustment obtains the required cooling air volume for the low-temperature section. , represented as: in, This is the proportionality coefficient.

[0016] The application of the technical solution of the present invention has the following beneficial effects: The control method of this invention realizes the power generation using waste heat in the high-temperature section and the normal cooling effect of sinter in the medium-temperature and low-temperature sections. It provides parameter guidance for the adjustment of cooling air volume in each temperature section, and achieves the triple purpose of controllable cooling of sinter, waste heat power generation and frequency conversion power saving.

[0017] Among them, the variable frequency fan in the low temperature section can adjust the air volume according to the heat calculation value of the sinter at monitoring point 3 and the set average ore temperature and heat setting value at monitoring point 4, so as to realize the variable frequency fan input of cooling air to the low temperature section according to the real-time heat dissipation demand, thereby achieving the purpose of variable frequency power saving.

[0018] Meanwhile, the control method of the present invention uses the changes in the calculated heat values ​​at monitoring points 1 and 2, as well as the setpoint for the exhaust gas temperature, to control the changes in the heat values ​​at monitoring points 1 and 2. Matching the required cooling air volume can effectively ensure that the flue gas temperature is kept within a reasonable range, providing a stable heat energy supply for waste heat power generation.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the cooling route of sinter in the annular cooler. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more complete description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0023] Example: like Figure 1 As shown, sinter 1 slowly moves from the inlet to the outlet of the annular cooler, sequentially passing through a high-temperature section, a medium-temperature section, and a low-temperature section to complete its own cooling. Each temperature section of the annular cooler is equipped with a blower at the bottom, which blows air from the bottom to cool the sinter 1. After cooling the sinter 1, the cooling air becomes exhaust gas, and the temperature of the exhaust gas varies significantly between the different temperature sections. In actual engineering, the entire cooling process of the annular cooler is expected to be controllable, keeping the sinter 1 within a suitable temperature range in each temperature section, so that the material temperature at the outlet reaches below the set temperature.

[0024] In order to make reasonable use of the waste heat of the annular cooler exhaust gas, this embodiment provides a control method for the waste heat recovery of the annular cooler, so as to ensure the waste heat recovery and utilization under the premise that the annular cooler cools the sinter 1 normally.

[0025] To achieve waste heat recovery control in this embodiment, the high-temperature section inlet (i.e., the ring cooler inlet), the junction of the medium-high temperature section, the junction of the medium-low temperature section, and the low-temperature section outlet (i.e., the ring cooler outlet) of the annular cooler are sequentially designated as monitoring points 1#, 2#, 3#, and 4#. Thermal imagers are installed at monitoring points 1#, 2#, 3#, and 4# to collect the real-time surface temperature of the sinter 1 at each monitoring point. A layer thickness gauge is installed at monitoring point 1# to measure the thickness (i.e., the layer height) of the sinter 1 layer inside the annular cooler. Thermocouples are installed inside the high-temperature, medium-temperature, and low-temperature sections to measure the exhaust gas temperature in each section. Preferably, thermocouples are installed before and after the blower in each section, with multiple thermocouples arranged along the transverse direction of the trolley at each location. The specific number of thermocouples at each location can be determined based on the on-site process environment and the width of the annular cooler. The measured exhaust gas temperature value within each section can be the average of the thermocouple measurements within that section.

[0026] Furthermore, the sintered ore will be processed at intervals. A single cutting process is performed to divide the sinter entering the annular cooler into several blocks, with each block representing a time interval. The total amount of sinter transported internally, wherein the sinter blocks are in a fan-shaped structure, and the inner radius of the sinter blocks is... The outer radius is .

[0027] Furthermore, the waste heat recovery strategy in this embodiment utilizes the waste heat from the high-temperature section for power generation, while the waste heat from the medium-temperature and low-temperature sections is not recovered, ensuring the normal cooling of the sinter by the annular cooler. To achieve this waste heat recovery strategy, the control method is specifically as follows: Based on the exhaust gas temperature setpoint in the high-temperature section Calculated heat value of sintered ore block at monitoring point #1 And the calculated heat value of the sintered ore block at monitoring point #2 Calculate the required cooling air volume for the high-temperature section. ; Based on the heat calculation value of the sintered ore block at monitoring point #2 The set average ore temperature at monitoring point #3 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the mid-temperature range. ; Based on the heat calculation value of the sintered ore block at monitoring point #3 The set average ore temperature at monitoring point #4 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the low-temperature section. .

[0028] Specifically, adopt If any one of monitoring points 1#, 2#, 3#, and 4# is used, then the sintered ore is divided into blocks at that monitoring point. Calculated heat value at the location Represented as: in, For monitoring points The quality of the sintered ore blocks. The specific heat capacity of the sintered ore blocks For monitoring points The average temperature of the sintered ore blocks The density of the sinter. The inner radius of the sinter block is given. The outer radius of the sinter block. The operating angular velocity of the annular cooler. For monitoring points The average height of the sintered ore blocks Pi The time interval for dividing sintered ore.

[0029] Furthermore, since the temperature of the upper and lower layers of sinter is basically uniform at the high-temperature section entrance (i.e., monitoring point 1), meaning the internal average temperature is consistent with the surface temperature, the average temperature of the sinter blocks at monitoring point 1 is... Equal to the average surface temperature measurement of the sintered ore block at monitoring point #1 Substituting these values ​​into the formula yields the calculated heat value of the sintered ore block at monitoring point #1. .

[0030] Furthermore, since the sintered ore blocks at monitoring points #2, #3, and #4 have undergone cooling by cooling air, the sintered ore blocks exhibit a characteristic of lower temperatures at the bottom and higher temperatures at the top. Therefore, it can be assumed that the temperature at monitoring points #2, #3, and #4 decreases linearly from top to bottom. If any one of monitoring points #2, #3, and #4 is represented, then the monitoring point... The temperature change at the location is expressed as: in, This indicates that the sintered ore is divided into blocks at the monitoring point. The average surface temperature measurement at that location, Indicates monitoring point The cooling gradient at the location ( (Settings can be made based on experience). Indicates monitoring point The average height of the sintered ore blocks Indicates monitoring point Sintered ore blocks at any height Temperature value at any location (i.e., any layer thickness).

[0031] Therefore, monitoring points Average mineral temperature at the location Represented as: in, Indicates monitoring point The average temperature of the ore at that location.

[0032] Furthermore, this embodiment also provides a stratified ore temperature prediction model to calculate the average ore temperature at monitoring points #2, #3, and #4. Specifically: use This represents any one of monitoring points #2, #3, and #4, with a set scaling factor. monitoring points The sintered ore at the location is divided into upper and lower layers, with the upper layer denoted as... The lower-level block representation is as follows ,in, , Indicates monitoring point The average height of the sintered ore blocks; Then, at any height position in the upper-level block The temperature of the ore at that location is expressed as: in, Indicates monitoring point At any height position in the upper layer block The temperature of the ore at that location This is a coefficient related to the particle size distribution, typically ranging from 10⁻⁵⁰℃ / m. ; This indicates that the sintered ore is divided into blocks at the monitoring point. The average surface temperature measurement at the location; Furthermore, at any height position in the lower-level blocks The temperature of the ore at that location is expressed as: in, Indicates monitoring point At any height position in the lower layer block The temperature of the ore at that location; This is a material constant; for sinter, it is approximately 15-20. Indicates the wind speed of the cooling air. , for The temperature of the ore at an altitude.

[0033] Divide the upper layer into equal parts along the height direction. If there are multiple sub-layers, the sum of the mineral temperatures of each sub-layer can be expressed as: Divide the lower layer into equal sections along the height direction. If there are multiple sub-layers, the sum of the mineral temperatures of each sub-layer can be expressed as: Therefore, monitoring points Average mineral temperature at the location Represented as: in, and All are segmentation step sizes. and They can be equal or unequal.

[0034] After obtaining monitoring points Average mineral temperature at the location Then, the monitoring points can be calculated by substituting them into the formula. Calculated heat value at the location .

[0035] This embodiment provides two average mineral temperatures. Each calculation method has its advantages. Calculating the average ore temperature based on linear cooling has the advantages of fewer calculation parameters and higher calculation efficiency; while the method of calculating the average ore temperature by layer has the advantages of higher calculation accuracy and more accurate calculated values.

[0036] Furthermore, in this embodiment, the heat generated from the flue gas (i.e., the heat from the exhaust gas) originates from the heat dissipation of the sintered ore in the high-temperature section. Multiple blowers are reserved in the high-temperature section, and to increase the heat generated from the flue gas, typically 1-2 blowers are controllable and used. The flue gas temperature (i.e., the exhaust gas temperature) is maintained by adjusting the cooling airflow. Therefore, based on the exhaust gas temperature setpoint of the high-temperature section... Calculated heat value of sintered ore block at monitoring point #1 And the calculated heat value of the sintered ore block at monitoring point #2 Calculate the required cooling air volume for the high-temperature section Specifically: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. The temperature of the cooling air input to the high-temperature section ( (Generally, ambient temperature) For heat utilization efficiency, the exhaust gas temperature setpoint The target flue gas temperature is set according to the power generation requirements.

[0037] In this embodiment, the changes in heat calculation values ​​at monitoring points 1 and 2, as well as the exhaust gas temperature setpoint, are used to analyze the results. Matching the required cooling airflow effectively ensures that the flue gas temperature remains within a reasonable range, providing a stable heat supply for waste heat power generation. However, when the sintered ore first enters the annular cooler, the heat value of the sintered ore block at monitoring point #2 cannot be directly calculated. You can set one based on experience. The value is used to adjust the cooling airflow, or it can be calculated to obtain the value when the air cooler is working normally. After setting the value, start calculating the required cooling air volume for the high-temperature section in real time. .

[0038] Furthermore, the measured temperature of the exhaust gas in the high-temperature section... It can be obtained through thermocouple measurement, and therefore can also be based on the exhaust gas temperature setpoint. With exhaust gas temperature measurement value The difference between them is used as feedback to adjust the cooling air volume required for the high-temperature section. Specifically: in, This is the proportionality coefficient.

[0039] To obtain the required cooling air volume in the high-temperature section Then, the cooling airflow input to the high-temperature section can be controlled to reach the target airflow value. The air volume of the blower can be controlled independently to obtain the target value. Then, prioritize turning on one blower at full capacity. If the air volume input in the high-temperature section exceeds the target air volume... Then reduce the air volume of the blower. If the air volume input in the high-temperature section is less than the target air volume... Then turn on another blower until the air volume input to the high-temperature section reaches the target air volume. until.

[0040] Furthermore, when the exhaust gas temperature in the high-temperature section stabilizes at... When the power generation per unit time is expressed as: in, This refers to the cooling airflow input to the high-temperature section. The density of the exhaust gas, The specific heat capacity of the exhaust gas. The outlet temperature of the exhaust gas after heating steam in the high-temperature section during power generation ( (obtained by measuring the outlet air temperature) For power generation efficiency, This refers to the amount of electricity generated per unit of time.

[0041] Furthermore, after the high-temperature section has stabilized, the following control method can be used to handle small fluctuations in airflow (for example, when the average heat value fluctuation at the inlet of the high-temperature section does not exceed the set range). Specifically, this involves collecting data over a period of time. The average value and The average value, then based on The changes are used to dynamically adjust the cooling air volume required in the high-temperature section. : in, This indicates a period of stable operation in the high-temperature range. The average value, This indicates a period of stable operation in the high-temperature range. The average value, This is the proportionality coefficient.

[0042] Furthermore, based on the calculated heat values ​​of the sintered ore blocks at monitoring point #2... The set average ore temperature at monitoring point #3 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the mid-temperature range. Specifically: Among them, the exhaust gas temperature setpoint in the medium temperature section It is related to the average ore temperature at monitoring points #2 and #3 of the sintered ore block, and is expressed as: Among them, the heat setpoint of the sintered ore block at monitoring point #3 Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. For heat utilization rate, The temperature of the cooling air input to the medium temperature range ( (Generally, ambient temperature) The average temperature of the sintered ore block at monitoring point #2. The set average ore temperature for the sintered ore blocks at monitoring point #3. This is the proportionality coefficient. The average height of the sintered ore block at monitoring point #3. The quality of the sintered ore blocks at monitoring point #3.

[0043] Furthermore, the set average ore temperature The temperature can be set based on experience to control the cooling effect of the medium-temperature zone on sinter.

[0044] In this embodiment, the average ore temperature at the outlet of the medium-temperature section is set. and heat setting value To adjust the cooling airflow input to the intermediate temperature section, ensure that the sinter temperature is reduced below the target value in the intermediate temperature section, thus guaranteeing the normal cooling function of the intermediate temperature section. Furthermore, the cooling airflow adjustment for the intermediate temperature section is the same as for the high temperature section: first, fully operate one blower, then adjust the airflow according to the input airflow and the target airflow. Based on the relationship between the two, further adjust the input air volume until the input air volume is... until.

[0045] Furthermore, the actual average mine temperature at monitoring point #3 can be calculated using a thermal imager. Based on the set average ore temperature at monitoring point #3 for sintered ore blocks and actual average ore temperature The difference between them is used as feedback to adjust the cooling air volume required for the mid-temperature range. , represented as: in, This is the proportionality coefficient.

[0046] Furthermore, after the temperature range has stabilized, the following control method can be used to handle small fluctuations in airflow (for example, when the average heat value fluctuation at the temperature range inlet does not exceed the set range). Specifically, this involves collecting data over a period of time. The average value and The average value, then based on The changes dynamically adjust the required cooling air volume in the mid-temperature range. : in, This indicates a period of stable operation in the mid-temperature range. The average value, This indicates a period of stable operation in the mid-temperature range. The average value, This is the proportionality coefficient.

[0047] Furthermore, based on the calculated heat values ​​of the sintered ore blocks at monitoring point #3... The set average ore temperature at monitoring point #4 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the low-temperature section. Specifically: Among them, the exhaust gas temperature setpoint in the low-temperature section It is related to the average ore temperature at monitoring points #3 and #4 of the sintered ore block, and is expressed as: Heat setpoint of sintered ore block at monitoring point #4 Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. For heat utilization rate, The temperature of the cooling air input to the low-temperature section ( (Generally, ambient temperature) The average temperature of the sintered ore block at monitoring point #3. The set average ore temperature for the sintered ore blocks at monitoring point #4. This is the proportionality coefficient. The average height of the sintered ore block at monitoring point #4. The quality of the sintered ore blocks at monitoring point #4.

[0048] In this embodiment, the average ore temperature at the outlet of the low-temperature section is set. and heat setting value This is used to adjust the cooling airflow input in the low-temperature section, ensuring that the sinter temperature can be reduced below the target value (usually below 100℃) in the low-temperature section, thus guaranteeing the normal cooling function of the low-temperature section. Furthermore, the target value is obtained. The air volume is then adjusted by a variable frequency fan. This allows the variable frequency fan to adjust the air volume according to demand, thereby achieving the goal of saving electricity.

[0049] Furthermore, the actual average mine temperature at monitoring point #4 can be calculated using a thermal imager. Based on the set average ore temperature at monitoring point #4 for sintered ore blocks and actual average ore temperature The difference between them is used as feedback to adjust the cooling airflow required for the low-temperature section. , represented as: in, This is the proportionality coefficient.

[0050] Furthermore, after the low-temperature section has stabilized, the following control method can be used to handle small fluctuations in airflow during the low-temperature section (for example, when the average heat value fluctuation at the inlet of the low-temperature section does not exceed the set range). Specifically, this involves collecting data over a period of time. The average value and The average value, then based on The changes are used to dynamically adjust the cooling air volume required in the low-temperature section. : in, This indicates a period of stable operation in the low-temperature range. The average value, This indicates a period of stable operation in the low-temperature range. The average value, This is the proportionality coefficient.

[0051] Preferably, the set average ore temperature The settings can be configured as follows: in, The maximum mine temperature set for monitoring point #4. This is the proportionality coefficient.

[0052] Furthermore, the proportionality coefficient The determination method can be as follows: obtain the area of ​​each temperature zone at monitoring point #4, the surface mineral temperature of each temperature zone, and the average surface mineral temperature at monitoring point #4. (i.e., the average surface mineral temperature within the measurement range), each temperature zone is sorted by surface mineral temperature from smallest to largest to construct a histogram, where the horizontal axis represents surface mineral temperature and the vertical axis represents the area of ​​the temperature zone. Starting from the temperature zone with the highest surface mineral temperature, the highest surface mineral temperature at monitoring point #4 is the surface mineral temperature corresponding to the sum of the areas of the temperature zones that accounts for 10% of the total area. ,but .

[0053] For example: the area of ​​the 10℃ temperature zone is 50. The area of ​​the 15℃ temperature zone is 30. The area of ​​the 20℃ temperature zone is 5 The area of ​​the 25℃ temperature zone is 5 The area of ​​the 30℃ temperature zone is 5 The area of ​​the 35℃ temperature zone is 5 Starting from the highest temperature of 35℃ and moving down to the lowest, the area and proportion of the 35℃ and 30℃ temperature zones are 10%, so 30℃ is chosen as the highest surface mineral temperature. .

[0054] Of course, the above is only One setting method, but those skilled in the art can also set it based on experience. This is to ensure the cooling effect in the low-temperature section.

[0055] Preferably, to avoid frequent adjustments of cooling airflow at different temperature ranges, the following is adopted: It represents any one of the high temperature range, medium temperature range, and low temperature range. Indicates temperature range The required cooling air volume will be determined based on the site conditions and the temperature range. Set a fluctuation range for exhaust gas temperature. According to temperature range Last cooling airflow and temperature range The current calculation parameters are used to calculate the temperature range. Exhaust gas temperature ,like Then there is no need to adjust the cooling airflow, that is, the current Otherwise, it needs to be based on the temperature range. Recalculate the cooling airflow using the calculated parameters. .

[0056] in, Temperature range The lower limit of the exhaust gas temperature. Temperature range The upper limit of exhaust gas temperature; the calculation of cooling air volume for each temperature range based on calculation parameters has been clearly explained above. Based on this, those skilled in the art can calculate the exhaust gas temperature by modifying the above calculation formula. Therefore, this embodiment does not describe in detail how to back-calculate the exhaust gas temperature. .

[0057] Preferably, in this embodiment, the unit for the mass of sintered ore blocks is... Specific heat capacity of sintered ore blocks The unit is The units for cooling air temperature, exhaust gas temperature (including measured and set values), and outlet air temperature are all [missing information]. sinter density The unit is The inner radius of the sinter block and outer radius The units are all in meters (m), representing the angular velocity of the annular cooler. The unit is The average height of the sintered ore blocks is in meters (m), and the time interval for dividing the sintered ore blocks is... The unit is The units for the average ore temperature, surface ore temperature, and ore temperature at any height in the sintered ore blocks are all... The units for the heat setpoint and the heat calculation value are: Cooling fan speed The unit is The unit of cooling air volume is exhaust gas density The unit is specific heat capacity of exhaust gas The unit is Electricity generation Units are .

[0058] The control method in this embodiment realizes the power generation using waste heat in the high-temperature section and the normal cooling effect of sinter in the medium-temperature and low-temperature sections. It provides parameter guidance for the adjustment of cooling air volume in each temperature section, and achieves the triple purpose of controllable cooling of sinter, waste heat power generation and frequency conversion power saving.

[0059] The control method in this embodiment uses the changes in heat calculation values ​​at monitoring points 1 and 2, as well as the exhaust gas temperature setpoint. Matching the required cooling air volume can effectively ensure that the flue gas temperature is kept within a reasonable range, providing a stable heat energy supply for waste heat power generation.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for realizing waste heat recovery from an annular cooler, characterized in that, The high-temperature section inlet, the junction of the medium-high temperature section, the junction of the medium-low temperature section, and the low-temperature section outlet of the annular cooler are sequentially designated as monitoring points #1, #2, #3, and #4. The control method includes: Based on the exhaust gas temperature setpoint in the high-temperature section Calculated heat value of sintered ore block at monitoring point #1 And the calculated heat value of the sintered ore block at monitoring point #2 Calculate the required cooling air volume for the high-temperature section. ; Based on the heat calculation value of the sintered ore block at monitoring point #2 The set average ore temperature at monitoring point #3 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the mid-temperature range. ; Based on the heat calculation value of the sintered ore block at monitoring point #3 The set average ore temperature at monitoring point #4 for sintered ore blocks and heat setting value Calculate the required cooling air volume for the low-temperature section. .

2. The control method according to claim 1, characterized in that, use If any one of monitoring points 1#, 2#, 3#, and 4# is used, then the sintered ore is divided into blocks at that monitoring point. Calculated heat value at the location Represented as: in, For monitoring points The quality of the sintered ore blocks. The specific heat capacity of the sintered ore blocks For monitoring points The average temperature of the sintered ore blocks The density of the sinter. The inner radius of the sinter block is given. The outer radius of the sinter block. The operating angular velocity of the annular cooler. For monitoring points The average height of the sintered ore blocks Pi The time interval for dividing sintered ore.

3. The control method according to claim 2, characterized in that, Average ore temperature at monitoring point #1 Equal to the average surface temperature measurement of the sintered ore block at monitoring point #1 ; The average mine temperature at monitoring points #2, #3, and #4 is expressed as follows: use This refers to any one of monitoring points #2, #3, or #4. Average ore temperature of sintered ore blocks Represented as: in, This indicates that the sintered ore is divided into blocks at the monitoring point. The average surface temperature measurement at that location, Indicates monitoring point The cooling gradient at that point, Indicates monitoring point The average height of the sintered ore blocks; Or, adopt This refers to any one of monitoring points #2, #3, or #4. Average ore temperature of sintered ore blocks Represented as: Set the scaling factor monitoring points The sintered ore at the location is divided into upper and lower layers, with the upper layer denoted as... The lower-level block representation is as follows ,in, , Indicates monitoring point The average height of the sintered ore blocks; Divide the upper layer into equal parts along the height direction. Each sub-layer has a sum of its mineral temperature. Represented as: Divide the lower layer into equal sections along the height direction. Each sub-layer has a sum of its mineral temperature. Represented as: Then monitoring point Average ore temperature of sintered ore blocks Represented as: in, and All are segmentation step sizes. This indicates that the sintered ore is divided into blocks at the monitoring point. The average surface temperature measurement at that location, The coefficient is related to the particle size factor. This is the material constant. This indicates the wind speed of the cooling air. for The temperature of the ore at an altitude.

4. The control method according to any one of claims 2-3, characterized in that, Cooling air volume required for high-temperature section Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. This refers to the temperature of the cooling air input to the high-temperature section. This refers to the utilization rate of heat.

5. The control method according to claim 4, characterized in that, Based on the exhaust gas temperature setpoint in the high-temperature section With exhaust gas temperature measurement value The difference between them is used as feedback to adjust the cooling air volume required for the high-temperature section. Specifically: in, This is the proportionality coefficient.

6. The control method according to claim 1, characterized in that, The exhaust gas temperature in the high-temperature section is The amount of electricity generated per unit time is expressed as: in, This refers to the cooling airflow input to the high-temperature section. The density of the exhaust gas, The specific heat capacity of the exhaust gas. The outlet temperature is the temperature of the exhaust gas after heating the steam in the high-temperature section during power generation. For power generation efficiency, This refers to the amount of electricity generated per unit of time.

7. The control method according to any one of claims 2-3, characterized in that, The required cooling air volume for the intermediate temperature range Represented as: Among them, the exhaust gas temperature setpoint in the medium temperature range Represented as: Heat setpoint of sintered ore block at monitoring point #3 Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. For heat utilization rate, This refers to the temperature of the cooling air input to the mid-temperature section. The average temperature of the sintered ore block at monitoring point #2. The set average ore temperature for the sintered ore blocks at monitoring point #3. This is the proportionality coefficient. The average height of the sintered ore block at monitoring point #3. The quality of the sintered ore blocks at monitoring point #3.

8. The control method according to claim 7, characterized in that, Based on the set average ore temperature at monitoring point #3 for sintered ore blocks and actual average ore temperature Feedback adjustment obtains the required cooling air volume for the mid-temperature range. , represented as: in, This is the proportionality coefficient.

9. The control method according to any one of claims 2-3, characterized in that, The required cooling air volume for the low-temperature section Represented as: Among them, the exhaust gas temperature setpoint in the low-temperature section Represented as: Heat setpoint of sintered ore block at monitoring point #4 Represented as: in, The density of the exhaust gas, The specific heat capacity of the exhaust gas. For heat utilization rate, This refers to the temperature of the cooling air input to the low-temperature section. The average temperature of the sintered ore block at monitoring point #3. The set average ore temperature for the sintered ore blocks at monitoring point #4. This is the proportionality coefficient. The average height of the sintered ore block at monitoring point #4. The quality of the sintered ore blocks at monitoring point #4.

10. The control method according to claim 9, characterized in that, Based on the set average ore temperature at monitoring point #4 for sintered ore blocks and actual average ore temperature Feedback adjustment obtains the required cooling air volume for the low-temperature section. , represented as: in, This is the proportionality coefficient.

Images