An automatic setting method of an evaporative cooler outlet temperature setting value

Abstract

The application discloses an automatic setting method for setting an outlet temperature of an evaporative cooler, wherein the outlet of the evaporative cooler is connected with an inlet of an electrostatic precipitator through a dust removal pipeline, and the automatic setting method comprises the following steps: S100, acquiring a current ambient temperature of an open environment; S200, calculating a pipeline temperature drop of the dust removal pipeline under the current ambient temperature according to the current ambient temperature; S300, acquiring an internal temperature of the electrostatic precipitator under the highest dust removal efficiency, and setting the internal temperature as an inlet temperature of the electrostatic precipitator; S400, calculating a preset evaporative cooler outlet temperature according to the pipeline temperature drop and the inlet temperature of the electrostatic precipitator; and S500, setting the evaporative cooler outlet temperature as the preset evaporative cooler outlet temperature. The preset evaporative cooler outlet temperature set by the automatic setting method for setting the outlet temperature of the evaporative cooler is automatically corrected with the temperature change, and the accurate control of the inlet temperature of the electrostatic precipitator is realized.

Description

Technical Field

[0001] This invention relates to the field of dry dust removal technology for vanadium extraction converters, and in particular to an automatic setting method for the outlet temperature setpoint of an evaporative cooler. Background Technology

[0002] The primary dust removal process in the 200t vanadium extraction converter employs a dry dust removal technology, with the electrostatic precipitator (EP) being the core of the dry dust removal system. To ensure stable operation and high dust removal efficiency of the EP, the inlet temperature must be appropriate. Too low a temperature will affect dust removal efficiency, while too high a temperature can lead to deformation of the internal anode plates and cathode wires, and blockage of the glycerin tubing. To ensure a suitable EP inlet temperature while preventing ash blockage and scale buildup in the evaporative cooler (EC) system, the ultimate control point is the EC outlet temperature. Because there is a relatively long dust removal pipeline between the EC outlet and the EP inlet, there is a temperature drop in the pipeline. This temperature drop will vary with seasonal and weather changes. Therefore, the target temperature control for the EC outlet will differ.

[0003] The existing solution involves technicians manually adjusting the EC outlet temperature setpoint according to seasonal changes, typically every four months. However, this reliance on manual, timed adjustments prevents the EC outlet temperature from being adjusted in real-time to reflect temperature variations. Since the EC outlet temperature setpoint is manually set on the HMI screen, problems arise if technicians fail to update the setpoint promptly after temperature changes.

[0004] Therefore, existing technologies still need improvement. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes an automatic setting method for the outlet temperature setpoint of an evaporative cooler. This method enables the evaporative cooler outlet temperature setpoint to change automatically and can be updated in real time according to seasonal and weather changes.

[0006] The present invention discloses an automatic setting method for the outlet temperature setpoint of an evaporative cooler, wherein the outlet of the evaporative cooler is connected to the inlet of an electrostatic precipitator via a dust removal pipe, and the automatic setting method includes:

[0007] S100 obtains the current ambient temperature of the open-air environment;

[0008] S200 calculates the temperature drop of the dust removal pipeline under the current ambient temperature based on the current ambient temperature;

[0009] S300 obtains the internal temperature of the electrostatic precipitator at its highest dust removal efficiency and sets the internal temperature as the inlet temperature of the electrostatic precipitator.

[0010] S400 calculates the preset evaporator outlet temperature based on the pipe temperature drop and the electrostatic precipitator inlet temperature;

[0011] S500 sets the evaporator outlet temperature to the preset evaporator outlet temperature.

[0012] Furthermore, when the measured ambient temperature is within the ambient temperature threshold range, steps S100 to S500 are executed.

[0013] Furthermore, if the measured ambient temperature exceeds the ambient temperature threshold range, steps S100 to S500 are not executed, the evaporator outlet temperature is set to the constant value of the evaporator outlet temperature, and an abnormal ambient temperature is indicated.

[0014] Furthermore, the ambient temperature threshold range is -5°C to 50°C.

[0015] Furthermore, in step S100, the current ambient temperature is determined by using an ambient temperature detection thermocouple.

[0016] Further, step S200, "calculating the pipe temperature drop of the dust removal pipe at the current ambient temperature based on the current ambient temperature," includes:

[0017] Based on the production process requirements, determine the constant temperature values ​​corresponding to different lengths of dust removal pipelines during production.

[0018] The temperature drop of the dust removal pipeline is obtained by calculation using a first relational equation, which is:

[0019] Pipeline temperature drop = constant temperature value - current ambient temperature.

[0020] Furthermore, step S400, "calculating the preset evaporative cooler outlet temperature based on the pipe temperature drop and the electrostatic precipitator inlet temperature," includes:

[0021] Preset evaporator outlet temperature = pipe temperature drop + electrostatic precipitator inlet temperature.

[0022] Furthermore, when the ambient temperature changes by ±1℃, steps S100 to S500 are executed. When the ambient temperature changes by ±1℃, the ambient temperature is taken as an integer value, and steps S100 to S500 are executed according to the PLC's scan cycle (tens of milliseconds). Within the PLC's scan cycle, as long as the ambient temperature changes, the calculated preset evaporator outlet temperature changes accordingly.

[0023] Furthermore, the outlet temperature of the evaporative cooler is constant at 295 degrees Celsius.

[0024] Furthermore, in step S500, the evaporator outlet temperature setting is performed by automatically calculating the water spray volume and controlling the water spray volume through the PLC to cool down to the preset evaporator outlet temperature.

[0025] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0026] The automatic setting method for the evaporative cooler outlet temperature setpoint of this invention aims to more accurately control the EC outlet temperature and EP inlet temperature. After seasonal and temporal changes, ambient temperature values ​​are collected. The ambient temperature varies with the seasons and time, and the preset EC outlet temperature setpoint is automatically determined through formula calculation. This setpoint is automatically corrected according to changes in ambient temperature, without human intervention or manual setting, truly achieving precise control of the EC outlet temperature and EP inlet temperature. This solves the problem of system malfunctions caused by the failure to promptly update the EC outlet temperature setpoint after seasonal temperature changes.

[0027] The automatic setting method for the evaporator outlet temperature setpoint of the present invention automatically corrects the preset evaporator outlet temperature as the temperature changes, realizing precise control of the EP inlet temperature, ensuring that the electrostatic precipitator inlet temperature is within a suitable range, resulting in high dust removal efficiency, stable operation of the internal equipment of the dust collector, reduced downtime, and ensuring the safe and stable operation of the 200t vanadium extraction converter dry dust removal system.

[0028] The automatic setting method for the evaporative cooler outlet temperature setpoint of the present invention can achieve automatic setting even under conditions of large daytime and nighttime temperature differences. This overcomes the problem that manual setting cannot distinguish between day and night, resulting in more accurate preset evaporative cooler outlet temperature values ​​and better system regulation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram showing the connection between an evaporative cooler and an electrostatic precipitator according to an embodiment of the present invention;

[0031] Figure 2 This is a flowchart illustrating an embodiment of the automatic setting method for the outlet temperature setpoint of an evaporative cooler according to the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0033] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0034] like Figure 1 As shown, the converter dry dust removal process involves cooling the flue gas generated during the smelting process in a vaporization cooling duct before introducing it into an evaporative cooler (EC). Inside the evaporative cooler, the flue gas is further cooled to a specific temperature. Then, a fan installed at the outlet of an electrostatic precipitator (EP) draws the cooled flue gas into the EP for further electrostatic dust removal. The outlet of the evaporative cooler and the inlet of the electrostatic precipitator are connected by a dust removal pipeline.

[0035] To achieve automatic adjustment of the evaporative cooler outlet temperature setpoint, which can be updated in real time according to seasonal and weather changes, this embodiment provides the following solution. For example... Figure 2 As shown, an automatic setting method for the outlet temperature setpoint of an evaporative cooler is disclosed. This automatic setting method generally includes the following steps:

[0036] S100 obtains the current ambient temperature of the open-air environment;

[0037] S200 calculates the temperature drop of the dust removal pipeline based on the current ambient temperature.

[0038] S300 obtains the internal temperature of the electrostatic precipitator at its highest dust removal efficiency and sets the internal temperature as the inlet temperature of the electrostatic precipitator.

[0039] S400 calculates the preset evaporative cooler outlet temperature based on the pipe temperature drop and the electrostatic precipitator inlet temperature.

[0040] The S500 sets the evaporator outlet temperature to the preset evaporator outlet temperature.

[0041] According to one embodiment of the present invention, when the measured ambient temperature is within the ambient temperature threshold range, steps S100 to S500 are executed.

[0042] According to another embodiment of the present invention, when the measured ambient temperature exceeds the ambient temperature threshold range, steps S100 to S500 are not executed, the evaporator outlet temperature is set to the constant value of the evaporator outlet temperature, and an abnormal ambient temperature is indicated.

[0043] The ambient temperature threshold range is from -5℃ to 50℃.

[0044] Preferably, the current ambient temperature can be determined using an ambient temperature sensing thermocouple. The signal is sent to the PLC, and the ambient temperature value can be used directly. In specific operating conditions, the ambient temperature sensing thermocouple is installed outside the factory building, near the electrostatic precipitator, and measures the local open-air ambient temperature.

[0045] This is because the automatic setting method for the evaporative cooler outlet temperature setpoint requires accurate ambient temperature detection. If the ambient temperature thermocouple is damaged, resulting in an abnormal ambient temperature value, the calculated preset evaporative cooler outlet temperature will deviate significantly from the normal value, affecting system stability. Therefore, the ambient temperature must be between -5℃ and 50℃. If the ambient temperature exceeds this range, the program will assign a constant evaporative cooler outlet temperature value to the EC outlet temperature setpoint, and the calculated preset evaporative cooler outlet temperature will not be executed. Simultaneously, an alarm window will pop up on the HMI indicating an abnormal ambient temperature.

[0046] The outlet temperature of the evaporative cooler is always 295 degrees Celsius.

[0047] Typically, the outlet temperature of an evaporative cooler is between 270 and 320 degrees Celsius. If the ambient temperature is found to be abnormal and the calculated setpoint is not within the normal range, the program will assign a fixed value to the preset evaporative cooler outlet temperature, usually 295 degrees Celsius, so that the system adjustment will not have any problems.

[0048] According to an embodiment of the present invention, step S200, "calculating the pipe temperature drop of the dust removal pipe at the current ambient temperature based on the current ambient temperature," includes:

[0049] Based on the production process requirements, determine the constant temperature values ​​corresponding to different lengths of dust removal pipelines during production.

[0050] The temperature drop of the dust collection duct is obtained through calculation using the first relational equation, which is:

[0051] Pipeline temperature drop = constant temperature value - current ambient temperature (the lower the ambient temperature, the greater the pipeline temperature drop; the higher the ambient temperature, the smaller the pipeline temperature drop).

[0052] Specifically, based on production experience, the constant temperature value varies depending on the length of the dust collection pipe being manufactured. Therefore, through accumulated experience and relevant industrial trials during the production process, the corresponding constant temperature values ​​for different dust collection pipe lengths were determined, as shown in Table 1.

[0053] Table 1

[0054]

[0055] The dust removal duct has a diameter of 2420 mm. For example, the duct from the outlet of the evaporative cooler (EC) of boiler #1 to the inlet of the electrostatic precipitator (EP) is about 307 meters long, and the constant temperature value is 130℃ based on a large amount of data.

[0056] According to an embodiment of the present invention, step S400, "calculating the preset evaporative cooler outlet temperature based on the pipe temperature drop and the electrostatic precipitator inlet temperature," includes:

[0057] Preset evaporator outlet temperature = pipe temperature drop + electrostatic precipitator inlet temperature.

[0058] Specifically,

[0059] From: Electrostatic precipitator inlet temperature = Evaporative cooler outlet temperature - Pipeline temperature drop, we can derive: Preset evaporative cooler outlet temperature = Pipeline temperature drop + Electrostatic precipitator inlet temperature

[0060] From: Pipe temperature drop = constant temperature value - current ambient temperature, we can derive: Preset evaporator outlet temperature = constant temperature value - current ambient temperature + electrostatic precipitator inlet temperature

[0061] Let the preset evaporator outlet temperature be M, the current ambient temperature be N, the electrostatic precipitator inlet temperature be A, and the constant temperature be B. The following formula is derived:

[0062] M = B - N + A

[0063] The final conclusion is that the preset evaporator outlet temperature (M) changes with the current ambient temperature (N).

[0064] Preferably, steps S100 to S500 are executed when the ambient temperature changes by ±1℃. When the ambient temperature changes by ±1℃, the ambient temperature is taken as an integer value, and steps S100 to S500 are executed according to the PLC scan cycle (tens of milliseconds). Within the PLC scan cycle, as long as the ambient temperature changes, the calculated preset evaporator outlet temperature changes accordingly. This ensures that the preset evaporator outlet temperature obtained by the automatic setting method changes with temperature variations. Previously, technicians manually modified the EC outlet temperature setting value based on seasonal changes, typically every four months. The original manual setting value did not distinguish between day and night. This automatic setting method automatically changes the EC outlet temperature setting value according to changes in ambient temperature throughout the day and night, resulting in more accurate settings and better system adjustment.

[0065] According to an embodiment of the present invention, in step S500, the setting of the evaporator outlet temperature is performed by automatically calculating the water spray volume and controlling the water spray volume by the PLC to cool down to the preset evaporator outlet temperature.

[0066] EC spray control is divided into three stages. The first stage is fixed valve opening control, the second stage is fixed flow control, and the third stage is to precisely adjust the spray volume through continuous PID control based on the EC outlet temperature setpoint and the actual EC outlet temperature deviation.

[0067] Since this invention mainly relates to improvements in the automatic setting of the outlet temperature setpoint of the evaporative cooler, there are no particular limitations on other steps and specific operations of the EC spray control, which can be carried out with reference to existing technologies.

[0068] The method in this embodiment enables the EC outlet temperature setpoint to be automatically set instead of manually, reducing the workload of operators and solving the problem of system failure caused by failure to manually modify the setpoint in a timely manner after seasonal changes.

[0069] Example

[0070] The preset outlet temperature of the evaporator cooler is M = B - N + A, where the current ambient temperature is N, the inlet temperature of the electrostatic precipitator is A, and the constant temperature is B.

[0071] For example, in summer, for boiler #1: A is 200 degrees Celsius and B is 130 degrees Celsius. The calculated preset evaporator outlet temperature is shown in Table 2 below. The time indicates the ambient temperature and preset evaporator outlet temperature at that time point. It does not mean that the preset evaporator outlet temperature is only calculated at that time point.

[0072] Table 2

[0073]

[0074] Taking winter as an example for boiler #1: A is taken as 200 degrees Celsius, B is taken as 130 degrees Celsius, and the calculated preset evaporator outlet temperature is shown in Table 3 below. The time indicates the ambient temperature and preset evaporator outlet temperature at that time point, and does not mean that the preset evaporator outlet temperature is only calculated at that time point.

[0075] Table 3

[0076]

[0077] It should be noted that the components or steps in the above embodiments can be interchanged, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of this invention, and the protection scope of this invention should not be limited to the above embodiments.

[0078] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0079] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. An automatic setting method for the outlet temperature setpoint of an evaporative cooler, wherein the outlet of the evaporative cooler is connected to the inlet of an electrostatic precipitator via a dust removal pipe, characterized in that, The automatic setting method includes: S100 obtains the current ambient temperature of the open-air environment; S200 calculates the pipe temperature drop of the dust removal pipe at the current ambient temperature based on the current ambient temperature; determines the constant temperature value corresponding to the dust removal pipe when it is produced at different lengths according to the production process requirements; the pipe temperature drop of the dust removal pipe is obtained by calculation through a first relational equation, which is: pipe temperature drop = constant temperature value - current ambient temperature; S300 obtains the internal temperature of the electrostatic precipitator at its highest dust removal efficiency and sets the internal temperature as the inlet temperature of the electrostatic precipitator. S400 calculates the preset evaporator outlet temperature based on the pipe temperature drop and the electrostatic precipitator inlet temperature. The preset evaporator outlet temperature is obtained by calculation through a second relational equation, which is: preset evaporator outlet temperature = pipe temperature drop + electrostatic precipitator inlet temperature. S500 sets the evaporator outlet temperature to the preset evaporator outlet temperature.

2. The automatic setting method for the outlet temperature setpoint of the evaporative cooler according to claim 1, characterized in that, If the measured ambient temperature is within the ambient temperature threshold range, then proceed with steps S100 to S500.

3. The automatic setting method for the outlet temperature setpoint of the evaporative cooler according to claim 1, characterized in that, If the measured ambient temperature exceeds the ambient temperature threshold range, steps S100 to S500 are not executed, the evaporator outlet temperature is set to the constant value of the evaporator outlet temperature, and an abnormal ambient temperature is indicated.

4. The automatic setting method for the outlet temperature setpoint of the evaporative cooler according to claim 2 or 3, characterized in that, The ambient temperature threshold range is -5℃ to 50℃.

5. The automatic setting method for the outlet temperature setpoint of an evaporative cooler according to claim 2, characterized in that, In step S100, the current ambient temperature is determined by using an ambient temperature detection thermocouple.

6. The automatic setting method for the outlet temperature setpoint of the evaporative cooler according to claim 2, characterized in that, When the ambient temperature changes by ±1℃, steps S100 to S500 are executed.

7. The automatic setting method for the outlet temperature setpoint of the evaporative cooler according to claim 3, characterized in that, The outlet temperature of the evaporative cooler is constant at 295 degrees Celsius.

8. The automatic setting method for the outlet temperature setpoint of the evaporative cooler according to claim 2, characterized in that, In step S500, the evaporator outlet temperature setting is performed by automatically calculating the water spray volume and controlling the water spray volume through the PLC to cool down to the preset evaporator outlet temperature.

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