A method and device for controlling the intermediate point temperature of a direct current boiler unit

Abstract

The present invention discloses a method and device for controlling the intermediate point temperature of a direct current boiler unit. The method includes: collecting the operating data of the direct current boiler unit; judging the operating state of the unit according to the operating data of the unit; and determining the integral PID calculation result according to the operating state of the unit to realize the control of the intermediate point temperature of the direct current boiler unit. Based on the intermediate point temperature given function, the present invention proposes to give an intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimize the water-coal relationship, automatically give an intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically correct the intermediate point temperature given function based on the main steam temperature deviation. Compared with the disadvantage that the traditional operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden of the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

Description

Technical Field

[0001] The invention relates to the field of boilers, and in particular to a method and device for controlling the intermediate point temperature of a direct current boiler unit. Background Art

[0002] As the requirements for energy-saving and consumption-reduction indicators become higher and higher, the selection of direct-current boiler units also tends to choose supercritical units. When the unit is in a steady-state load, as long as the water-coal ratio remains unchanged, the superheat of the steam at the inlet of the direct-current boiler separator can be guaranteed to be stable. When the unit changes load, the water-coal ratio must be changed according to a certain rule to fully utilize the fuel heat and ensure the smooth operation of the unit. The water-coal ratio of supercritical units has an important influence on the main steam pressure, main reheat steam temperature, etc. The core of direct-current boiler control is the water-coal ratio, with water-coal regulation as the main rough adjustment means of steam temperature control, and water spray cooling as an auxiliary fine adjustment means.

[0003] The existing intermediate point temperature control scheme is a single-loop PID control system. The intermediate point temperature set value is manually set by the power plant operator based on field experience, and the PID controller outputs the feedwater flow correction value based on the deviation between the set value and the measured value. However, the frequent manual modification of the intermediate point temperature set value increases the workload of the operator; secondly, the set value is given based on operating experience, which is somewhat blind, and the main reheat steam temperature overheating phenomenon often occurs during actual operation. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a method and device for controlling the intermediate point temperature of a direct current boiler unit, which solves the problems of increased workload of operating personnel, blindness, and poor accuracy due to the existing intermediate point temperature control method.

[0005] According to a first aspect, an embodiment of the present invention provides a method for controlling an intermediate point temperature of a once-through boiler unit, comprising:

[0006] Collecting the operation data of once-through boiler units;

[0007] Determine the unit operation status according to the unit operation data;

[0008] The integral PID calculation result is determined according to the operating status of the unit to achieve control of the intermediate point temperature of the direct current boiler unit.

[0009] The intermediate point temperature control method of a direct current boiler unit provided by the embodiment of the present invention is based on the intermediate point temperature given function, proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimizes the water-coal relationship, can automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically corrects the intermediate point temperature given function based on the main steam temperature deviation. Compared with the disadvantage of the traditional method that the operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden on the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0010] In combination with the first aspect, in the first implementation of the first aspect, the once-through boiler unit operation data includes: a current load instruction, a current main steam pressure deviation, a current unit coal feed rate, and a current unit water feed rate, and judging the unit operation state according to the unit operation data includes:

[0011] Obtaining a load instruction within a preset time period, and determining a first output result when the current load instruction and each of the load instructions within the preset time period meet a first preset requirement;

[0012] When the absolute value of the main steam pressure deviation meets a second preset requirement, determining a second output result;

[0013] Obtaining the coal supply amount of the unit within a preset period, and when the current coal supply amount of the unit and the coal supply amount of the unit within the preset period meet a third preset requirement, determining a third output result;

[0014] Acquire the water supply amount of the unit within a preset period of time, and when the current water supply amount of the unit and the water supply amount of the unit within the preset period of time meet a fourth preset requirement, determine a fourth output result;

[0015] When the first output result, the second output result, the third output result and the fourth output result all exist, and after a preset time delay, it is determined that the operating state of the unit is a substable state.

[0016] In combination with the first embodiment of the first aspect, in the second embodiment of the first aspect,

[0017] When the current load instruction and each of the load instructions within the preset time period meet the first preset requirement, determining the first output result includes: performing difference operations on the current load instruction and each of the load instructions within the three preset time periods in sequence, and determining the operation results respectively; when the absolute value of each of the operation results is less than the first preset value, determining the first output result;

[0018] When the absolute value of the main steam pressure deviation meets the second preset requirement, determining the second output result includes: when the absolute value of the main steam pressure deviation is less than the second preset value, determining the second output result;

[0019] When the current coal supply amount of the unit and the coal supply amount of the unit meet the third preset requirement, determining the third output result includes: performing a difference operation on the current coal supply amount of the unit and the coal supply amount of the unit to determine a first difference; when the absolute value of the first difference is less than a third preset value, determining the third output result;

[0020] When the current water supply of the unit and the water supply of the unit meet the fourth preset requirement, determining the fourth output result includes: performing a difference operation on the current water supply of the unit and the water supply of the unit to determine the second difference; when the absolute value of the second difference is less than the fourth preset value, determining the fourth output result.

[0021] In combination with the first embodiment of the first aspect, in the third embodiment of the first aspect, the once-through boiler unit operation data further includes: a current main steam temperature deviation and a current desuperheating water flow rate, and the judging of the unit operation state according to the unit operation data further includes:

[0022] When the absolute value of the current main steam temperature deviation is less than a fifth preset value, determining a fifth output result;

[0023] When the absolute value of the current cooling water flow rate is less than a sixth preset value, determining a sixth output result;

[0024] When the first output result, the second output result, the third output result, the fourth output result, the fifth output result and the sixth output result all exist, and after a preset time delay, it is determined that the operating state of the unit is a steady state.

[0025] In combination with the third implementation manner of the first aspect, in the fourth implementation manner of the first aspect, determining the integral PID calculation result according to the operating state of the unit includes:

[0026] When the unit is in a steady state, the average temperature of the middle point of the current state is obtained according to a set time period until the steady state ends; the middle point temperature reference value corresponding to the load instruction is determined by using the middle point temperature average and the load instruction corresponding to the steady state;

[0027] When the unit is in a substable state, a PID integral is used to determine a midpoint temperature correction value;

[0028] The intermediate point temperature reference value is corrected by using the intermediate point temperature correction value to eliminate the main steam temperature deviation.

[0029] In combination with the fourth implementation of the first aspect, in the fifth implementation of the first aspect, it also includes: when the steady state ends, resetting the PID integral, and the resetting is setting the output result to 0.

[0030] In combination with the fourth implementation of the first aspect, in the sixth implementation of the first aspect, when the operating state of the unit is a steady state, obtaining the average temperature of the intermediate point of the current state according to the set time period includes:

[0031] When the unit is in a steady-state operation state, the number of occurrences of the pulse signal and the accumulated intermediate point temperature are obtained;

[0032] When the pulse signal exists, the current midpoint temperature of the current state is obtained, and the accumulated midpoint temperature sum is summed with the current midpoint temperature to determine the current midpoint temperature sum;

[0033] Determine the mean value of the midpoint temperature by using the current midpoint temperature and the number of occurrences;

[0034] When the pulse signal does not exist, the accumulated intermediate point temperature sum is outputted until the pulse signal exists.

[0035] The intermediate point temperature control method of a direct current boiler unit provided by the embodiment of the present invention is based on the intermediate point temperature given function, proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimizes the water-coal relationship, can automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically corrects the intermediate point temperature given function based on the main steam temperature deviation. Compared with the disadvantage of the traditional method that the operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden on the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0036] According to the second aspect, an intermediate point temperature control device of a once-through boiler unit provided by an embodiment of the present invention includes:

[0037] The first processing module is used to collect the operation data of the once-through boiler unit;

[0038] A second processing module, used for determining the operating state of the unit according to the unit operating data;

[0039] The third processing module is used to determine the integral PID calculation result according to the operating state of the unit to achieve the control of the intermediate point temperature of the direct current boiler unit.

[0040] The intermediate point temperature control device of the direct current boiler unit provided in this embodiment is based on the intermediate point temperature given function, proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimizes the water-coal relationship, can automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically corrects the intermediate point temperature given function based on the main steam temperature deviation. Compared with the traditional disadvantage that the operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden on the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0041] According to the third aspect, an embodiment of the present invention provides an electronic device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to execute the method for controlling the intermediate point temperature of a direct current boiler unit described in the first aspect or any one of the embodiments of the first aspect.

[0042] According to the fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable the computer to execute the intermediate point temperature control method of the direct current boiler unit described in the first aspect or any one embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 is a flow chart of a general feedwater setting method for a supercritical unit according to an embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of conventional control of the intermediate point temperature according to an embodiment of the present invention;

[0046] Figure 3 is a flow chart of a method for controlling an intermediate point temperature of a once-through boiler unit according to an embodiment of the present invention;

[0047] Figure 4 is a logic block diagram of a unit operation status determination process according to a preferred embodiment of the present invention;

[0048] Figure 5 is a schematic diagram of the intermediate point temperature setting principle according to the present invention;

[0049] Figure 6 is a schematic diagram of a given function of the intermediate point temperature according to the present invention;

[0050] Figure 7 is a schematic diagram of obtaining a steady-state intermediate point temperature average according to an embodiment of the present invention;

[0051] Figure 8 is a functional module schematic diagram of an intermediate point temperature control device of a once-through boiler unit according to an embodiment of the present invention;

[0052] Fig. 9 It is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0054] Supercritical thermal power units refer to units with working fluid parameters in the boiler, the main steam pressure exceeds the critical pressure of 22.129MPa, and the main steam temperature exceeds the critical temperature of 374.15℃. Because there is no steam drum, the heating, evaporation and conversion of feed water into superheated steam are completed in one go. The stability of boiler steam parameters (including pressure and temperature) depends on the balance between generator power and boiler evaporation, as well as the balance between coal feed and water feed. Since there is no drum heat storage, the feed water flow directly reflects the steam flow. The heat absorption of the boiler and the steam consumption of the turbine must be balanced. The ratio of the unit's coal feed and water feed must be maintained within a reasonable balance range, which is the WFR (Water Fuel Rate) of the direct current boiler.

[0055] When the unit is in a steady-state load, as long as the water-coal ratio remains unchanged, the steam superheat at the inlet of the direct-current furnace separator can be kept stable. When the unit changes load, the water-coal ratio must be changed according to a certain rule to fully utilize the fuel heat and ensure the smooth operation of the unit. The water-coal ratio of the supercritical unit has an important influence on the main steam pressure, main reheat steam temperature, etc. The core of direct-current boiler control is the water-coal ratio. Water-coal regulation is used as the main coarse adjustment method for steam temperature control, and water spray cooling is used as an auxiliary fine adjustment method. If the unit's coal consumption and feed water flow differ by 10%, the deviation of the superheater outlet steam temperature can reach about 100°C. Optimizing the water-coal ratio control helps improve the unit's operating stability and variable load capacity. The water-coal ratio is generally given by the boiler manufacturer as a preset broken line function F(X) according to the unit's designed coal type, and a fixed water-coal ratio relationship is achieved based on the proportional relationship of the broken line function.

[0056] The midpoint temperature of a direct current boiler refers to the steam temperature at the outlet of the steam-water separator. It can reflect whether the water-coal ratio is reasonable and reflect the change trend of the superheated steam temperature in advance. The midpoint temperature is usually used to correct the feed water flow. The correction process is as follows: Figure 1 shown.

[0057] Existing intermediate point temperature control solutions are as follows: Figure 2 As shown in the figure, it is a single-loop PID control system. The intermediate point temperature set value is manually set by the power plant operator based on field experience, and the PID controller outputs the feedwater flow correction value based on the deviation between the set value and the measured value. For example: the operator sets the intermediate point temperature to 25°C, and the actual measured value is 20°C, then the PID reduces the feedwater flow correction value, thereby reducing the total feedwater flow to increase the intermediate point temperature. Conversely, if the operator sets the intermediate point temperature to 25°C and the actual measured value is 30°C, then the PID increases the feedwater flow correction value, thereby increasing the total feedwater flow to increase the intermediate point temperature.

[0058] The fundamental purpose of the intermediate point temperature control is to correct the feed water in advance, so as to ensure that the water-coal ratio of the unit is in an ideal state and the main steam temperature does not fluctuate greatly. In the existing intermediate point temperature control scheme, the intermediate point temperature setting value is manually set by the operator, and the frequent modification of the intermediate point temperature setting value increases the workload of the operator; secondly, the setting value is based on operating experience, which is somewhat blind, and the main reheat steam temperature often exceeds the temperature during actual operation.

[0059] In this embodiment, a method for controlling the intermediate point temperature of a direct current boiler unit is provided, which can be used in electronic devices such as computers, mobile phones, tablet computers, etc. Figure 3 is a flow chart of a method for controlling an intermediate point temperature of a once-through boiler unit according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0060] S11, collecting the operation data of the direct current boiler unit.

[0061] Among them, the existing methods and technologies are used to collect the operating data of the direct current boiler unit, including load instructions, coal feed rate, feed water flow, main steam pressure deviation, main steam temperature deviation, main steam flow, and cooling water flow, a total of 7 groups of data.

[0062] S12, judging the unit operation status according to the unit operation data.

[0063] In this embodiment, the unit operation data collected in the above steps is used to judge the unit operation state, which specifically includes a steady state and a sub-steady state. The specific judgment process will be described in detail below and will not be repeated in this embodiment.

[0064] S13, determining the integral PID calculation result according to the unit operation status to realize the control of the intermediate point temperature of the direct current boiler unit.

[0065] The calculation result of the integral PID, i.e., the midpoint temperature adjustment value, is determined by using the unit operation status determined in the above steps to achieve control of the midpoint temperature of the direct current boiler unit. The specific adjustment and calculation process will be described below.

[0066] The intermediate point temperature control method of the direct current boiler unit provided in this embodiment is based on the intermediate point temperature given function, proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimizes the water-coal relationship, can automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically corrects the intermediate point temperature given function based on the main steam temperature deviation. Compared with the traditional disadvantage that the operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden on the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0067] In another embodiment, a method for controlling the intermediate point temperature of a once-through boiler unit is provided, comprising the following steps:

[0068] S21, collecting the operation data of the direct current boiler unit.

[0069] Please refer to step S11 for details, which will not be described in detail in this embodiment.

[0070] S22, judging the unit operation status according to the unit operation data. The direct current boiler unit operation data includes: current load instruction, current main steam pressure deviation, current unit coal supply, current unit water supply, and direct current boiler unit operation data also includes: current main steam temperature deviation, current cooling water flow.

[0071] In this embodiment, the above step S22 specifically further includes:

[0072] S221, obtaining a load instruction within a preset time period, and when the current load instruction and each load instruction within the preset time period meet a first preset requirement, determining a first output result;

[0073] Specifically, the current load instruction is subjected to pairwise difference calculations with each load instruction within three preset time periods respectively, and calculation results are determined respectively; when the absolute value of each calculation result is less than a first preset value, a first output result is determined.

[0074] S222, when the absolute value of the main steam pressure deviation meets the second preset requirement, determine the second output result; in this embodiment, when the absolute value of the main steam pressure deviation is less than the second preset value, determine the second output result.

[0075] S223, obtain the unit coal supply within the preset time period, and when the current unit coal supply and the unit coal supply within the preset time period meet the third preset requirement, determine the third output result; in this embodiment, the current unit coal supply and the unit coal supply in the previous time period of the current time period are subtracted to determine the first difference; when the absolute value of the first difference is less than the third preset value, the third output result is determined.

[0076] S224, obtain the unit water supply within the preset time period, and when the current unit water supply and the unit water supply within the preset time period meet the fourth preset requirement, determine the fourth output result; specifically, perform a difference operation on the current unit water supply and the unit water supply in the previous time period of the current time period to determine the second difference; when the absolute value of the second difference is less than the fourth preset value, determine the fourth output result.

[0077] S225, when the first output result, the second output result, the third output result and the fourth output result all exist, and after a preset delay time, it is determined that the unit operation state is a sub-stable state.

[0078] S226, when the absolute value of the current main steam temperature deviation is less than the fifth preset value, determine the fifth output result.

[0079] S227: When the absolute value of the current cooling water flow rate is less than the sixth preset value, determine the sixth output result.

[0080] S228, when the first output result, the second output result, the third output result, the fourth output result, the fifth output result and the sixth output result all exist, and after a preset delay time, it is determined that the unit operation state is a steady state.

[0081] In this embodiment, the specific preset value is set according to actual needs. This embodiment only takes the first preset value, the second preset value, the third preset value, etc. as examples, and is not limited thereto.

[0082] In practical applications, the detailed judgment of the unit operation status is as follows Figure 4 As shown, TL is the load instruction, MSPE is the main steam pressure deviation (pressure setting value minus actual value), FUEL is the coal supply, WATER is the water supply, and WT represents the unit in steady state. The specific judgment method is: the deviation of TL acquisition value from its acquisition value 1, 3, and 5 minutes ago is less than 0.2MW, and MSPE is less than 0.5MPa, and the deviation of FUEL acquisition value from the acquisition value 3 minutes ago is less than 3t / h, and the deviation of WATER acquisition value from the acquisition value 3 minutes ago is less than 30t / h. After the above conditions are met, the unit operation condition is judged to be sub-stable after a delay of 5 minutes. Figure 4 The delayed output blocks HSDELAY1, HSDELAY2, and HSDEALY3 output the values ​​of the TL load instruction 1 minute, 3 minutes, and 5 minutes ago, respectively. HSDELAY4 and HSDELAY5 output the values ​​of FUEL and WATER 3 minutes ago, respectively. SUB is a difference module, ABS is an absolute value module, LT is a less than module, AND is an AND gate, and TON is a rising delay module set to 5 minutes.

[0083] In addition to the sub-steady-state conditions, steady-state judgment also adds judgments on the main steam temperature deviation (MSTE) and the cooling water flow rate (JWS). When MSTE is less than 0.6℃ and JWS is less than 5t / h, with a delay of 5 minutes, the unit is judged to be in a steady state.

[0084] S23, determining the integral PID calculation result according to the unit operation status to realize the control of the intermediate point temperature of the direct current boiler unit.

[0085] Please refer to step S13 for details, which will not be described in detail in this embodiment.

[0086] The intermediate point temperature control method provided in this embodiment is based on the intermediate point temperature given function, and proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimize the water-coal relationship, and automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically correct the intermediate point temperature given function based on the main steam temperature deviation. Compared with the traditional disadvantage that the operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden on the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0087] In another embodiment, a method for controlling the intermediate point temperature of a once-through boiler unit is provided, the process comprising the following steps:

[0088] S31, collecting the operation data of the direct current boiler unit.

[0089] Please refer to step S21 for details, which will not be described in detail in this embodiment.

[0090] S32, judging the unit operation status according to the unit operation data.

[0091] Please refer to step S22 for details, which will not be described in detail in this embodiment.

[0092] S33, determine the integral PID calculation result according to the unit operation status to realize the control of the intermediate point temperature of the direct current boiler unit. The specific principle of the intermediate point temperature setting is as follows: Figure 5 As shown, the steady-state load MWD and the mean value of the intermediate point temperature MT1 are written into the intermediate point temperature setting function. The input of the intermediate point temperature setting function is the unit load instruction, and the output is the intermediate point temperature setting reference value BMT corresponding to the load instruction, such as Figure 6 As shown. Set the integral PID to correct the BMT. The difference between the integral PID and the conventional PID is that it cancels the proportional and differential effects and only retains the integral action. The setting of the integral action time can be adjusted according to the change characteristics of the intermediate point temperature and the main steam temperature during the actual operation of the unit. When the unit is in dynamic load change (non-steady state and sub-stable state), the integral PID input deviation is 0 and no correction is made. When the unit enters the steady state or sub-stable state, the integral PID input deviation is the main steam temperature deviation (set value minus actual value). The intermediate point temperature set value can be corrected according to the main steam temperature deviation. For example, if the deviation is 5°C, the integral PID gradually increases the intermediate point temperature correction value CP to increase the intermediate point temperature set value, thereby eliminating the main steam temperature deviation and improving the unit operation efficiency. After the unit ends in steady state, reset the integral PID output and set its output to 0.

[0093] In this embodiment, the above step S33 specifically further includes:

[0094] S331, when the unit is in a steady state, the average temperature of the middle point of the current state is obtained according to the set time period until the steady state ends; the middle point temperature reference value corresponding to the load instruction is determined by using the middle point temperature average and the load instruction corresponding to the steady state;

[0095] In practical applications, the midpoint temperature of the current state is obtained, that is, when the unit is in a steady-state operation state, the number of pulse signal occurrences and the accumulated midpoint temperature sum are obtained; when a pulse signal exists, the current midpoint temperature of the current state is obtained, the accumulated midpoint temperature sum is summed with the current midpoint temperature, and the current midpoint temperature sum is determined; the mean midpoint temperature is determined using the current midpoint temperature sum and the number of occurrences.

[0096] When there is no pulse signal, the accumulated intermediate point temperature sum is output until the pulse signal exists.

[0097] Specifically, the process of obtaining the steady-state intermediate point temperature and calculating the mean value is as follows: Figure 7 As shown,

[0098] 1. Load steady state WT, after a delay of 5 minutes through the delay block (No. 4), is output to three places: the first is the trigger pulse block (No. 11, the pulse time is set to 2s) to send out a 2s pulse; the second is the enable cycle pulse block TPTP (No. 12, set to output a 220ms pulse every 2 minutes, note: the pulse time is determined by the corresponding DCS system scan cycle, for a DCS with a scan cycle of 200ms, it can be set to 220ms); the third is the enable accumulation block (No. 6);

[0099] 2. Accumulation block COUNT (No. 8), the enable terminal (pin EN) input is the output of the pulse block (No. 11). If the input is logic "1", the accumulation function is executed. If it is logic "0", its output returns to 0 and no longer accumulates. After the enable condition is met, the input (pin IN) pulse signal is monitored. Every time a pulse is monitored, the output (pin OUT) value is incremented by 1.

[0100] 3. The SWITCH switch block (No. 1) input PV1 is connected to the ADD (No. 2) block output, and the input PV2 is connected to the SWITCH switch block (No. 3) output. Its control terminal S is connected to the output of the cyclic pulse block (No. 12). If the control terminal input is logical "1", it outputs PV1, otherwise it outputs PV2. The ADD block (No. 2) input 1 is the real-time intermediate point temperature of the unit, and input 2 is the output of the SWITCH switch block (No. 1). The specific workflow is: after the load steady state meets the conditions, the delay block (No. 4) outputs logic "1", the SWITCH (No. 3) output is equal to its input PV1 (that is, the output value of SWITCH (No. 1)), and the pulse block TPTP starts to output 220ms pulses every 2 minutes, that is, every 2 minutes, the SWITCH (No. 1) output value accumulates the real-time intermediate point temperature of the unit.

[0101] 4. Input 1 of the DIV division block (No. 5) is the accumulated value of the steady-state intermediate point temperature of the load (accumulated every 2 minutes), and input 2 is the output of the accumulator (No. 6). The accumulator (No. 6) is enabled after the unit is in steady state, and its output is automatically increased by 1 after each pulse signal output by the TPTP module is monitored by the input IN pin. The output of the DIV division block (No. 5) is equal to the accumulated value of the intermediate point temperature divided by the number of accumulations, which represents the average value of the intermediate point temperature under this steady-state condition.

[0102] 5. The switching condition of the SWITCH (No. 7) control terminal is: the output of the accumulator (No. 8) is equal to 1 (representing the first load steady state), and the delay block (No. 4) changes from logic "1" to "0" (representing the end of this steady state). After the above conditions are met, the pulse block (No. 9, pulse time is 2s) sends a 2s pulse and assigns the calculated mean value of the intermediate point temperature obtained by DIV (No. 5) to MT1. After the pulse of the pulse block (No. 9) disappears, the SWITCH (No. 7) control terminal switches to logic "0", and the output MT1 is automatically maintained.

[0103] 6. System recovery: After the steady-state condition is not met (the output of the delay block (No. 4) changes from logic "1" to "0"), MT1 is self-retained, and TPTP is no longer enabled and the output remains at logic "0", SWITCH (No. 3) output is equal to 0, SWITCH (No. 1) output is equal to 0, accumulator (No. 6) output is equal to 0, and DIV block (No. 5) output is equal to 0. The pulse block (No. 9, pulse time 2s) outputs logic "1", which is negated to logic "0", making the EN pin of the accumulator block (No. 8) logic "0", resetting its output to 0. At this point, the average temperature of the intermediate point under the steady-state condition is obtained, and the entire system including the accumulator (No. 8) is reset.

[0104] 7. MT1 is continuously updated as the unit continues to re-enter steady-state conditions.

[0105] S332, when the steady state ends, the PID integral is reset, and the reset is to set the output result to 0.

[0106] S333, when the unit is in a sub-stable state, the intermediate point temperature correction value is determined by using PID integration;

[0107] S334, using the mid-point temperature correction value to correct the mid-point temperature reference value to eliminate the main steam temperature deviation.

[0108] The intermediate point temperature control method of the direct current boiler unit provided in this embodiment is based on the intermediate point temperature given function, proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimizes the water-coal relationship, can automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically corrects the intermediate point temperature given function based on the main steam temperature deviation. Compared with the traditional disadvantage that the operator frequently modifies the intermediate point temperature setting value based on his own operating experience, the burden on the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0109] In this embodiment, a device for controlling the intermediate point temperature of a direct current boiler unit is also provided. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0110] The present invention discloses a device for controlling the intermediate temperature of a direct current boiler unit. Figure 8 As shown, including:

[0111] The first processing module 01 is used to collect the operation data of the once-through boiler unit;

[0112] The second processing module 02 is used to determine the unit operation status according to the unit operation data;

[0113] The third processing module 03 is used to determine the integral PID calculation result according to the unit operation status to realize the control of the intermediate point temperature of the direct current boiler unit.

[0114] The intermediate point temperature control device of the direct current boiler unit provided by the embodiment of the present invention is based on the intermediate point temperature given function, proposes to give the intermediate point temperature setting value suitable for the real-time operating state of the unit based on the historical operating data of the unit, optimizes the water-coal relationship, can automatically give the intermediate point temperature setting value suitable for the current operating condition of the unit, and automatically corrects the intermediate point temperature given function based on the main steam temperature deviation. Compared with the disadvantage of the traditional operator frequently modifying the intermediate point temperature setting value based on his own operating experience, the burden of the operator is reduced, and the given value takes into account the main steam temperature deviation of the unit, with the ultimate goal of eliminating the main steam temperature deviation, and the accuracy and efficiency are higher.

[0115] The present invention also provides an electronic device. Fig. 9 , Fig. 9 is a schematic diagram of the structure of an electronic device provided by an optional embodiment of the present invention, such as Fig. 9As shown, the electronic device may include: at least one processor 601, such as a CPU (Central Processing Unit), at least one communication interface 603, a memory 604, and at least one communication bus 602. The communication bus 602 is used to realize the connection and communication between these components. The communication interface 603 may include a display screen (Display), a keyboard (Keyboard), and the optional communication interface 603 may also include a standard wired interface and a wireless interface. The memory 604 may be a high-speed RAM memory (Random Access Memory) or a non-volatile memory (non-volatile memory), such as at least one disk storage. The memory 604 may optionally be at least one storage device located away from the aforementioned processor 601. The processor 601 may be combined with Figure 8 In the described device, the memory 604 stores an application program, and the processor 601 calls the program code stored in the memory 604 to execute any of the above method steps.

[0116] The communication bus 602 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The communication bus 602 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0117] Among them, the memory 604 may include a volatile memory (English: volatile memory), such as a random access memory (English: random-access memory, abbreviated: RAM); the memory may also include a non-volatile memory (English: non-volatile memory), such as a flash memory (English: flash memory), a hard disk drive (English: hard disk drive, abbreviated: HDD) or a solid-state drive (English: solid-state drive, abbreviated: SSD); the memory 604 may also include a combination of the above types of memory.

[0118] The processor 601 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and a NP.

[0119] The processor 601 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0120] Optionally, the memory 604 is also used to store program instructions. The processor 601 can call the program instructions to implement the intermediate point temperature control method of the once-through boiler unit as shown in the embodiment of the present application.

[0121] The embodiment of the present invention further provides a non-transitory computer storage medium, which stores computer executable instructions, and the computer executable instructions can execute the intermediate point temperature control method of the direct current boiler unit in any of the above method embodiments. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash Memory), a hard disk (HardDisk Drive, abbreviated: HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memory.

[0122] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for controlling the intermediate point temperature of a direct current boiler unit. It is characterized in that include: Collecting the operation data of once-through boiler units; Determine the unit operation status according to the unit operation data; Determine the integral PID calculation result according to the operating state of the unit to achieve control of the intermediate point temperature of the once-through boiler unit; The once-through boiler unit operation data includes: current load instruction, current main steam pressure deviation, current unit coal supply, current unit water supply, and the unit operation state is judged according to the unit operation data, including: Obtaining a load instruction within a preset time period, and determining a first output result when the current load instruction and each of the load instructions within the preset time period meet a first preset requirement; When the absolute value of the main steam pressure deviation meets a second preset requirement, determining a second output result; Obtaining the coal supply amount of the unit within a preset period, and when the current coal supply amount of the unit and the coal supply amount of the unit within the preset period meet a third preset requirement, determining a third output result; Acquire the water supply amount of the unit within a preset period of time, and when the current water supply amount of the unit and the water supply amount of the unit within the preset period of time meet a fourth preset requirement, determine a fourth output result; When the first output result, the second output result, the third output result and the fourth output result all exist, and after a preset time delay, it is determined that the operating state of the unit is a substable state; The current main steam temperature deviation and the current desuperheating water flow rate, the said judging the unit operation state according to the said unit operation data, further comprising: When the absolute value of the current main steam temperature deviation is less than a fifth preset value, determining a fifth output result; When the absolute value of the current cooling water flow rate is less than a sixth preset value, determining a sixth output result; When the first output result, the second output result, the third output result, the fourth output result, the fifth output result and the sixth output result all exist, and after a preset time delay, it is determined that the operating state of the unit is a steady state; Determining the integral PID calculation result according to the unit operation state includes: When the unit is in a steady state, the average temperature of the middle point of the current state is obtained according to a set time period until the steady state ends; the middle point temperature reference value corresponding to the load instruction is determined by using the middle point temperature average and the load instruction corresponding to the steady state; When the unit is in a substable state, a PID integral is used to determine a midpoint temperature correction value; The intermediate point temperature reference value is corrected by using the intermediate point temperature correction value to eliminate the main steam temperature deviation.

2. The method according to claim 1, It is characterized in that When the current load instruction and each of the load instructions within the preset time period meet the first preset requirement, determining the first output result includes: performing difference operations on the current load instruction and each of the load instructions within the three preset time periods in sequence, and determining the operation results respectively; when the absolute value of each of the operation results is less than the first preset value, determining the first output result; When the absolute value of the main steam pressure deviation meets the second preset requirement, determining the second output result includes: when the absolute value of the main steam pressure deviation is less than the second preset value, determining the second output result; When the current coal supply amount of the unit and the coal supply amount of the unit meet the third preset requirement, determining the third output result includes: performing a difference operation on the current coal supply amount of the unit and the coal supply amount of the unit to determine a first difference; when the absolute value of the first difference is less than a third preset value, determining the third output result; When the current water supply of the unit and the water supply of the unit meet the fourth preset requirement, determining the fourth output result includes: performing a difference operation on the current water supply of the unit and the water supply of the unit to determine the second difference; when the absolute value of the second difference is less than the fourth preset value, determining the fourth output result.

3. The method according to claim 2, It is characterized in that Also includes: When the steady state ends, the PID integral is reset, and the reset is to set the output result to 0.

4. The method according to claim 2, It is characterized in that When the unit is in a steady state, obtaining the average temperature of the intermediate point in the current state according to a set time period includes: When the unit is in a steady-state operation state, the number of occurrences of the pulse signal and the accumulated intermediate point temperature are obtained; When the pulse signal exists, the current midpoint temperature of the current state is obtained, and the accumulated midpoint temperature sum is summed with the current midpoint temperature to determine the current midpoint temperature sum; Determine the mean value of the midpoint temperature by using the current midpoint temperature and the number of occurrences; When the pulse signal does not exist, the accumulated sum of the intermediate point temperatures is outputted until the pulse signal exists.

5. A device for controlling the intermediate temperature of a once-through boiler unit, for executing the method according to any one of claims 1 to 4, It is characterized in that include: The first processing module is used to collect the operation data of the once-through boiler unit; A second processing module, used for determining the operating state of the unit according to the unit operating data; The third processing module is used to determine the integral PID calculation result according to the operating state of the unit to achieve the control of the intermediate point temperature of the direct current boiler unit.

6. An electronic device, It is characterized in that include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the intermediate point temperature control method of a direct current boiler unit according to any one of claims 1 to 4 by executing the computer instructions.

7. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the intermediate point temperature control method of a direct-current boiler unit according to any one of claims 1 to 4.

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