A method and device for monitoring water leakage of a copper smelting waste heat boiler

Abstract

This invention provides a method and apparatus for monitoring water leakage in a waste heat boiler used in copper smelting, comprising: acquiring the average value of water supply over multiple time periods; acquiring the average value of evaporation over multiple time periods; determining a monitoring value based on the average value of water supply, the average value of evaporation, the average value of wastewater discharge, and the average value of sampling; determining whether the boiler is leaking based on the monitoring value and an alarm threshold; and if so, issuing a water balance alarm signal; thereby enabling the timely detection of leaks in the waste heat boiler, improving the intrinsic safety level of the equipment, and reducing the maintenance difficulty for maintenance personnel.

Description

Technical Field

[0001] This invention relates to the field of waste heat boiler leakage monitoring technology, and more specifically, to a method and apparatus for monitoring leakage in copper smelting waste heat boilers. Background Technology

[0002] A minor internal leak occurred in the waste heat boiler. Due to the small size of the leak and its location inside the boiler flue, the operator was unable to detect the problem using existing inspection methods under the complex flue gas conditions. During this process, a small amount of leaked steam-water mixture reacted with the flue gas and dust in the boiler flue. The reactants caused the boiler pipes near the leak to thin. As the leak was discovered later and gradually enlarged, the affected area expanded until a large amount of steam-water mixture leaked. Only then did the operator notice the accident through sensory inspection and take emergency measures. However, by this time, the internal leak had already been going on for several hours or even days. With the delayed discovery, a small leak could escalate into a large-scale thinning of the boiler tube walls, leading to the scrapping of a large area of ​​boiler pipes.

[0003] In view of this, the present invention proposes a method and device for monitoring water leakage in a waste heat boiler for copper smelting, so as to detect the leakage point of the waste heat boiler in the first time, improve the inherent safety level of the equipment, and reduce the maintenance difficulty for maintenance operators. Summary of the Invention

[0004] The purpose of this invention is to provide a method for monitoring water leakage in a waste heat boiler for copper smelting, comprising: obtaining the average value of water supply over multiple time periods; obtaining the average value of evaporation over multiple time periods; determining a monitoring value based on the average value of water supply, the average value of evaporation, the average value of wastewater discharge, and the average value of sampling; determining whether the boiler is leaking water based on the monitoring value and an alarm threshold; and issuing a water balance alarm signal if the boiler is leaking water.

[0005] Furthermore, obtaining the average water supply volume over multiple time periods includes: acquiring water supply volume signals; performing configuration and data integration processing on the water supply volume signals to obtain the current cumulative water supply flow rate; acquiring the cumulative historical water supply flow rate values ​​from multiple set times ago; and obtaining the average water supply volume over multiple time periods based on the difference between the current cumulative water supply flow rate value and the cumulative historical water supply flow rate value.

[0006] Furthermore, obtaining the average evaporation amount over multiple time periods includes: acquiring a steam evaporation amount signal; configuring and compensating the steam evaporation amount signal with temperature and pressure to obtain a compensated steam flow rate value; integrating the compensated steam flow rate value to obtain a current cumulative steam flow rate value; acquiring multiple historical cumulative steam flow rates from a set time ago; and obtaining the average evaporation amount over multiple time periods based on the difference between the current cumulative steam flow rate value and the historical cumulative steam flow rate value.

[0007] Furthermore, the monitoring value is the difference between the average value of the water supply and the sum of the average value of the evaporation, the average value of the sewage discharge, and the average value of the sampling.

[0008] Furthermore, determining whether the boiler is leaking based on the monitored value and the alarm threshold includes: when the monitored value for a certain period of time is greater than the alarm threshold, determining that the boiler is leaking and issuing an alarm signal; otherwise, determining that the boiler is not leaking and continuing monitoring.

[0009] The purpose of this invention is to provide a water leakage monitoring device for a copper smelting waste heat boiler, comprising a feedwater flow monitoring module, a steam flow monitoring module, a steam pressure acquisition module, a steam temperature acquisition module, and a distributed control system. The feedwater flow monitoring module is communicatively connected to the distributed control system to acquire the average value of the feedwater flow over multiple time periods. The steam flow monitoring module, the steam pressure acquisition module, and the steam temperature acquisition module are communicatively connected to each other and to the distributed control system, respectively, to acquire the average value of the evaporation over multiple time periods. The distributed control system determines the monitoring value based on the average feedwater flow, the average evaporation, the blowdown volume, and the sampling volume. Based on the monitoring value and an alarm threshold, it determines whether the boiler is leaking; if so, it issues a water balance alarm signal.

[0010] Furthermore, the water supply flow monitoring module includes an integrator, a time delay unit, a subtractor, and a divider; the integrator's input is the water supply signal, and its output is the current cumulative water supply flow value; the time delay unit's input is the current cumulative water supply flow value and multiple set times, and its output is the historical cumulative water supply flow value; the subtractor's input is the current cumulative water supply flow value and the historical cumulative water supply flow value; the divider's input is the subtractor's output and the multiple set times, and its output is the average water supply flow value over multiple time periods.

[0011] Furthermore, the steam flow monitoring module includes a temperature and pressure compensation unit, an integrator, a time delay unit, a subtractor, and a divider. The temperature and pressure compensation unit receives inputs including steam evaporation signal, steam pressure signal, and steam temperature signal, and outputs a compensated steam flow value. The integrator receives the compensated steam flow value as input and outputs the current cumulative steam flow value. The time delay unit receives the current cumulative steam flow value and multiple set times as input and outputs the historical cumulative steam flow value. The subtractor receives the current cumulative steam flow value and the historical cumulative steam flow value as input. The divider receives the output of the subtractor and the multiple set times as input and outputs the average evaporation rate over multiple time periods.

[0012] Furthermore, the distributed control system includes a water balance alarm module, which comprises an adder, a subtractor, and a comparison unit. The inputs of the adder include the average value of evaporation, the average value of sewage discharge, and the average value of sampling. The inputs of the subtractor are the output of the adder and the average value of the water supply, and the output is the monitored value. The inputs of the comparison unit are the monitored value and the alarm threshold, and the output is the water balance alarm signal.

[0013] Furthermore, the issuance of the water balance alarm signal means that when the monitored value over a certain period of time is greater than the alarm threshold, it is determined that the boiler is leaking water and an alarm signal is issued; otherwise, it is determined that the boiler is not leaking water and monitoring continues.

[0014] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0015] The copper smelting waste heat boiler leakage monitoring method and device provided in some embodiments of this specification are highly sensitive to leakage monitoring. Even if it is a slight leak caused by a pinhole in the boiler pipeline, the system can detect the problem immediately and report the problem to the operator through an alarm. This effectively solves the problem of not being able to detect boiler leakage in time, reduces the risk value of the boiler, and achieves an intrinsic improvement in equipment safety. It is a relatively ideal boiler leakage monitoring method.

[0016] The copper smelting waste heat boiler leakage monitoring method and device provided in some embodiments of this specification can detect the problem as soon as leakage occurs, and avoid secondary accidents such as large-scale thinning after boiler system leakage. Attached Figure Description

[0017] Figure 1 An exemplary flowchart of a method for monitoring water leakage in a waste heat boiler for copper smelting, provided for some embodiments of the present invention;

[0018] Figure 2 An exemplary module diagram of a copper smelting waste heat boiler leakage monitoring device provided in some embodiments of the present invention;

[0019] Figure 3 This is an exemplary schematic diagram of a water supply flow monitoring module provided in some embodiments of the present invention;

[0020] Figure 4 This is an exemplary schematic diagram of a steam flow monitoring module provided in some embodiments of the present invention;

[0021] Figure 5 This is an exemplary schematic diagram of a water balance alarm module provided in some embodiments of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Figure 1 This is an exemplary flowchart illustrating a method for monitoring water leakage in a waste heat boiler used in copper smelting, provided in some embodiments of the present invention. In some embodiments, process 100 may be performed by... Figure 2 The device shown is used for execution.

[0024] like Figure 1 As shown, process 100 may include the following:

[0025] Step 110: Obtain the average water supply volume over multiple time periods.

[0026] Water supply volume can refer to the amount of water input into the boiler. The average water supply volume can refer to the average amount of water input into the boiler over each time period. For example, the amount of water input into the boiler per hour. Multiple time periods can refer to multiple time periods calculated backwards from the current time. For example, the previous 1 hour, the previous 3 hours, the previous 6 hours, the previous 9 hours, etc. In some embodiments, obtaining the average water supply volume over multiple time periods includes:

[0027] Acquire feedwater flow signals. Feedwater flow signals can refer to signals related to the amount of water injected into the boiler. In some embodiments, feedwater flow signals can be acquired through a boiler drum feedwater flow meter.

[0028] The feedwater flow signal is configured and integrated to obtain the current cumulative feedwater flow rate. The current cumulative feedwater flow rate can refer to the cumulative amount of water injected into the boiler.

[0029] This function retrieves the cumulative historical feedwater flow rates up to multiple set times. The set times can refer to multiple time periods, such as 1 hour, 3 hours, 6 hours, and 9 hours from the current time. The current cumulative feedwater flow rate at each set time can be used as the historical cumulative feedwater flow rate. The historical cumulative feedwater flow rate can be obtained by reading the cumulative feedwater flow rates from 1 hour, 6 hours, and 9 hours ago using the DT (Lag Time) function block in the waste heat boiler DCS operating system.

[0030] The average water supply value over multiple time periods is obtained by comparing the current cumulative water supply flow rate with the historical cumulative water supply flow rate. For example, dividing the difference between the current and historical cumulative water supply flow rates by the corresponding cumulative time gives the average water supply flow rate over that time period. For instance, if the cumulative water supply flow rate X2 is obtained at the current time of 12:00, and the cumulative water supply flow rate X1 is obtained at the set time of 11:00, with a time difference of H, then the average water supply flow rate between 11:00 and 12:00 is (X2 - X1) / H.

[0031] Step 120: Obtain the average value of evaporation over multiple time periods.

[0032] Evaporation rate can refer to the amount of water injected into the boiler that is evaporated into steam. The average evaporation rate can refer to the average amount of water evaporated into steam per time period. For example, the amount of water evaporated per hour. Multiple time periods can be the previous 1 hour, the previous 3 hours, the previous 6 hours, the previous 9 hours, etc. In some embodiments, obtaining the average evaporation rate over multiple time periods includes:

[0033] Acquire the steam evaporation rate signal. The steam evaporation rate signal can refer to a signal related to the steam evaporation rate. In some embodiments, the steam evaporation rate signal can be acquired through a steam flow meter in a steam drum.

[0034] The steam evaporation rate signal is configured and temperature and pressure compensated to obtain a compensated steam flow rate value. The compensated steam flow rate value can refer to the value obtained after compensating the steam flow rate. In some embodiments, a steam pressure transmitter and thermometer can be installed to perform temperature and pressure compensation calculations on the steam flow rate, reducing measurement errors.

[0035] The compensated steam flow rate is integrated to obtain the current cumulative steam flow rate. The current cumulative steam flow rate can refer to the amount of water evaporated in the current time.

[0036] Obtain historical cumulative steam flow values ​​from multiple set time points. The current cumulative steam flow value obtained at each set time point can be used as the historical cumulative steam flow value. The historical cumulative steam flow value can be obtained by using the DT (Lag Time) function block of the waste heat boiler DCS operating system to read the cumulative evaporation value from 1 hour, 6 hours, and 9 hours ago, respectively.

[0037] The average evaporation rate over multiple time periods is obtained by comparing the current cumulative steam flow rate with the historical cumulative steam flow rate. For example, dividing the difference between the current and historical cumulative steam flow rates by the corresponding cumulative time gives the average evaporation rate over that time period. For instance, if the cumulative steam flow rate Y2 is obtained at the current time of 12:00 and the cumulative steam flow rate Y1 is obtained at the set time of 11:00, with a time difference of H, then the average evaporation rate during the period from 11:00 to 12:00 is (Y2 - Y1) / H.

[0038] Step 130: Determine the monitoring value based on the average values ​​of water supply, evaporation, sewage discharge, and sampling.

[0039] Monitoring values ​​can refer to values ​​used to monitor whether the injected water volume is balanced with the used water volume. Average blowdown volume can refer to the average volume of boiler blowdown water discharged over each time period. Average sample volume can refer to the amount of water sampled from the boiler over each time period. Both average blowdown volume and average sample volume can be obtained empirically.

[0040] In some embodiments, the monitored value is the difference between the average feedwater flow rate and the sum of the average evaporation rate, the average blowdown rate, and the average sampling rate. For example, the 1-hour water balance value = 1-hour average feedwater flow rate - 1-hour average evaporation rate - 1-hour boiler blowdown rate - 1-hour boiler water sampling discharge rate; the 6-hour water balance value = 6-hour average feedwater flow rate - 6-hour average evaporation rate - 6-hour boiler blowdown rate - 6-hour boiler water sampling discharge rate; the 9-hour water balance value = 9-hour average feedwater flow rate - 9-hour average evaporation rate - 9-hour boiler blowdown rate - 9-hour boiler water sampling discharge rate.

[0041] Step 140: Based on the monitored values ​​and alarm thresholds, determine whether the boiler is leaking.

[0042] The alarm threshold can refer to a pre-set alarm value. For example, the alarm threshold can be 0; when the monitored value is greater than 0, a boiler leak is determined. In some embodiments, when the monitored value over a certain time period exceeds the alarm threshold, a boiler leak is determined, and an alarm signal is issued; otherwise, it is determined that the boiler is not leaking, and monitoring continues. For example, when the water balance monitoring value over 1 hour exceeds the alarm threshold, a leak is determined, and an alarm signal for 1 hour of monitoring is issued. As another example, when the water balance monitoring value over 3 hours exceeds the alarm threshold, a leak is determined, and an alarm signal for 3 hours of monitoring is issued.

[0043] Step 150: If yes, then issue a water balance alarm signal.

[0044] The water balance alarm signal can be used to alert users to boiler leaks. If the boiler is leaking, an alarm signal will be issued. For example, when the 1-hour water balance value / 3-hour water balance value / 6-hour water balance value / 9-hour water balance value > 0 tons, the system will issue an alarm.

[0045] Upon receiving the alarm information, the main operator of the waste heat boiler DCS (Distributed Control System) immediately begins to investigate whether the boiler is leaking water, identifies the problem in the first instance, and takes emergency measures.

[0046] Figure 2 This is an exemplary block diagram of a water leakage monitoring device for a copper smelting waste heat boiler, provided for some embodiments of the present invention. Figure 2 As shown, the copper smelting waste heat boiler leakage monitoring device may include a feedwater flow monitoring module, a steam flow monitoring module, a steam pressure acquisition module, a steam temperature acquisition module, and a distributed control system.

[0047] The water supply flow monitoring module is connected to the distributed control system to obtain the average water supply volume over multiple time periods.

[0048] The steam flow monitoring module, steam pressure acquisition module, and steam temperature acquisition module are interconnected and communicate with each other, and are also connected to the distributed control system to obtain the average value of evaporation over multiple time periods.

[0049] The distributed control system is used to determine monitoring values ​​based on the average values ​​of feedwater, evaporation, blowdown, and sampling. Based on these monitoring values ​​and alarm thresholds, it determines whether the boiler is leaking; if so, it issues a water balance alarm signal. Specifically, issuing a water balance alarm signal means that if the monitoring value over a certain time period exceeds the alarm threshold, it determines that the boiler is leaking and issues an alarm signal; otherwise, it determines that the boiler is not leaking and continues monitoring.

[0050] Figure 3 This is an exemplary schematic diagram of a water supply flow monitoring module provided in some embodiments of the present invention. For example... Figure 3 As shown, the water supply flow monitoring module may include an integrator, a time delay unit, a subtractor, and a divider.

[0051] The integrator takes the water supply signal as input and outputs the current cumulative water supply flow rate.

[0052] The input to the time delay unit is the current cumulative water flow rate and multiple set times, and the output is the historical cumulative water flow rate.

[0053] The inputs to the subtractor are the current cumulative water supply flow rate and the historical cumulative water supply flow rate.

[0054] The input to the divider is the output of the subtractor and multiple set times. The output is the average water supply rate over multiple time periods.

[0055] Figure 4 This is an exemplary schematic diagram of a steam flow monitoring module provided in some embodiments of the present invention. For example... Figure 4 As shown, the steam flow monitoring module includes a temperature and pressure compensation unit, an integrator, a time delay unit, a subtractor, and a divider.

[0056] The temperature and pressure compensation unit's inputs include steam evaporation rate signal, steam pressure signal, and steam temperature signal, and its output is the compensated steam flow rate value.

[0057] The integrator's input is the compensated steam flow rate, and its output is the current cumulative steam flow rate.

[0058] The input to the time delay unit is the current cumulative steam flow rate and multiple set times, and the output is the historical cumulative steam flow rate.

[0059] The inputs to the subtractor are the current cumulative steam flow rate and the historical cumulative steam flow rate.

[0060] The input to the divider is the output of the subtractor and multiple set times. The output is the average value of the evaporation over multiple time periods.

[0061] Figure 5 This is an exemplary schematic diagram of a water balance alarm module provided in some embodiments of the present invention. A distributed control system includes a water balance alarm module. Figure 5 As shown, the water balance alarm module includes an adder, a subtractor, and a comparison unit.

[0062] The inputs to the adder include the average value of evaporation, the average value of wastewater discharge, and the average value of sampling.

[0063] The input to the subtractor is the average of the output of the adder and the water supply, and the output is the monitoring value.

[0064] The inputs to the comparison unit are the monitored value and the alarm threshold, and the output is the water balance alarm signal.

[0065] The above are merely preferred embodiments of the present invention and are not intended to limit the present 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 method for monitoring water leakage in a waste heat boiler used in copper smelting, characterized in that, include: Obtain the average water supply volume over multiple time periods; The step of obtaining the average water supply volume over multiple time periods includes: Collect water supply signals; The water supply signal is configured and integrated to obtain the current cumulative water supply flow rate. Acquire the cumulative historical feedwater flow rate values ​​from multiple set time points; the cumulative historical feedwater flow rate values ​​are obtained through the DT function block of the waste heat boiler DCS operating system. Based on the difference between the current cumulative water supply flow rate and the historical cumulative water supply flow rate, the average water supply flow rate over multiple time periods is obtained; the difference between the current cumulative water supply flow rate and the historical cumulative water supply flow rate is divided by the corresponding cumulative time to obtain the average water supply flow rate over that time period. Obtain the average evaporation over multiple time periods, including: Collect steam evaporation rate signals; The steam evaporation signal is configured and temperature and pressure compensated to obtain the compensated steam flow rate value; the compensated steam flow rate value refers to the value obtained after compensating the steam flow rate; by installing a steam pressure transmitter and a thermometer, the temperature and pressure compensation calculation of the steam flow rate is performed. The compensated steam flow rate value is integrated to obtain the current cumulative steam flow rate value; Obtain the cumulative historical steam flow rate values ​​up to multiple set time points; Based on the difference between the current cumulative steam flow rate and the historical cumulative steam flow rate, the average value of evaporation over multiple time periods is obtained. The monitoring value is determined based on the average value of the water supply, the average value of the evaporation, the average value of the sewage discharge, and the average value of the sampling; the monitoring value is the difference between the average value of the water supply and the sum of the average value of the evaporation, the average value of the sewage discharge, and the average value of the sampling. Based on the monitored values ​​and alarm thresholds, determine whether the boiler is leaking water; If so, a water balance alarm signal will be issued.

2. The method for monitoring water leakage in a copper smelting waste heat boiler according to claim 1, characterized in that, The process of determining whether the boiler is leaking based on the monitored values ​​and alarm thresholds includes: If the monitored value exceeds the alarm threshold for a certain period of time, it is determined that the boiler is leaking water and an alarm signal is issued; otherwise, it is determined that the boiler is not leaking water and monitoring continues.

3. A leakage monitoring device for a waste heat boiler in copper smelting, characterized in that, It includes a water supply flow monitoring module, a steam flow monitoring module, a steam pressure acquisition module, a steam temperature acquisition module, and a distributed control system; The water supply flow monitoring module is communicatively connected to the distributed control system and is used to obtain the average value of water supply over multiple time periods; the water supply flow monitoring module includes a first integrator, a first time delay unit, a first subtractor, and a first divider; The input to the first integrator is the water supply flow signal, and the output is the current cumulative value of the water supply flow. The input to the first time delay unit is the current cumulative water flow rate and multiple set times, and the output is the historical cumulative water flow rate. The inputs to the first subtractor are the current cumulative water supply flow rate and the historical cumulative water supply flow rate; The input to the first divider is the output of the first subtractor and the multiple set times, and the output is the average water supply within multiple time periods; The steam flow monitoring module, the steam pressure acquisition module, and the steam temperature acquisition module are interconnected and respectively connected to the distributed control system to obtain the average value of evaporation over multiple time periods. The steam flow monitoring module includes a second temperature and pressure compensation unit, a second integrator, a second time delay unit, a second subtractor, and a second divider. The temperature and pressure compensation unit's inputs include steam evaporation rate signal, steam pressure signal, and steam temperature signal, and its output is a compensated steam flow rate value. The input to the second integrator is the compensated steam flow rate value, and the output is the current cumulative steam flow rate value; The input to the second time delay unit is the current cumulative steam flow rate and multiple set times, and the output is the historical cumulative steam flow rate. The inputs to the second subtractor are the current cumulative steam flow rate and the historical cumulative steam flow rate; The input to the second divider is the output of the second subtractor and the multiple set times, and the output is the average value of the evaporation amount within the multiple time periods; The distributed control system is used to determine the monitoring value based on the average value of the water supply, the average value of the evaporation, the average value of the sewage discharge, and the average value of the sampling; based on the monitoring value and the alarm threshold, it determines whether the boiler is leaking water; if so, it issues a water balance alarm signal; the monitoring value is the difference between the average value of the water supply and the sum of the average value of the evaporation, the average value of the sewage discharge, and the average value of the sampling.

4. The copper smelting waste heat boiler leakage monitoring device according to claim 3, characterized in that, The distributed control system includes a water balance alarm module, which includes an adder, a third subtractor, and a comparison unit. The inputs to the adder include the average value of the evaporation rate, the average value of the waste discharge rate, and the average value of the sampled amount; The input to the third subtractor is the average of the output of the adder and the water supply, and the output is the monitoring value. The comparison unit takes the monitored value and the alarm threshold as inputs and outputs a water balance alarm signal as output.

5. The copper smelting waste heat boiler leakage monitoring device according to claim 4, characterized in that, The water balance alarm signal is issued when the monitored value over a certain period of time is greater than the alarm threshold, indicating that the boiler is leaking and issuing an alarm signal; otherwise, it is determined that the boiler is not leaking and monitoring continues.

Images