A method for realizing dual-point protection judgment on DCS

Abstract

The present invention discloses a method for realizing dual-point protection judgment on DCS, and configures a dual-point protection macro command block algorithm by using basic function blocks such as AND, OR, NOT, upper and lower limit judgment, constant setting, switch quantity signal switching, RS trigger, etc. in DCS, and packages it into a dual-point protection macro module, which can be called in the same way as the basic function block when used, and sets the protection value and alarm value. By judging the temperature threshold and quality point of two monitoring points, when both the dual-points are normal, one point reaches the protection value and the other reaches the alarm value, and outputs "1". When there is a bad quality point or the change is too fast, this point is eliminated, and the remaining normal point single point reaches the protection value, and outputs "1". When both points are abnormal, outputs "0". The present invention uses the configuration of the basic functions of the DCS system to design a dual-point protection judgment method, which is safer and more accurate, reduces the tripping problem caused by possible misoperation, and can find the equipment failure point in time, reducing the workload of inspection and analysis.

Description

[Technical field]

[0001] The invention relates to the technical field of temperature protection of thermal power plants, and in particular to a method for realizing double-measurement-point protection judgment on a DCS. [Background technology]

[0002] Most of the important auxiliary bearing temperature protection designs in thermal power plants are single-point protection, such as forced draft fans, induced draft fans, primary fans, small units, pre-pumps, etc. Single-point protection has two hidden dangers: one is that inaccurate single-point measurement will lead to malfunction of the protection, and the other is that when the measurement point is of poor quality, the protection may refuse to operate. Changing the single-point measurement to a double-point measurement can effectively improve the reliability of the protection through the method of mutual verification.

[0003] In view of the hidden dangers of the single measuring point problem of the bearing temperature of the auxiliary equipment, the single measuring point is changed to a double measuring point. The judgment of the double measuring point protection requires the use of a new judgment method. The original design is: the protection value of one point and the alarm value of another point are mutually corroborated as the basis for judgment. At the same time, it is necessary to be compatible with the bad quality point judgment function block and the measuring point speed judgment. When a bad quality point appears or the rate changes too fast, the bad point needs to be eliminated and the single measuring point judgment can still be maintained. This requires compatibility with the previous single measuring point protection judgment mode. According to the above requirements, the double measuring point protection judgment plan needs to be re-compiled. [Summary of the invention]

[0004] The purpose of the present invention is to provide a method for realizing dual-point protection judgment on DCS, so as to solve the problems that most of the current important shaft machines and bearing temperature protection designs are single-point protection, inaccurate measurement, and single-point misjudgment when bad quality points and temperature change rate are too fast. The present invention changes the single-point into a dual-point, realizes mutual evidence between the two points, and is compatible with the bad quality point judgment function block and the point rate judgment, ensuring data accuracy.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for realizing dual-measurement point protection judgment on a DCS, utilizing an OR function block, an AND function block, a NON function block, a quality point judgment function block, an analog delay function block, a difference function block, an RS trigger, an upper limit judgment function block, a switch quantity signal switching function block, and a logic block in a DCS system, and configuring a dual-measurement point protection macro command algorithm, packaging it into a dual-measurement point protection macro module, which can be called in the same way as a basic function block when used, wherein the quality point judgment function block, the analog delay function block, the difference function block, and the RS trigger have two, and the upper limit judgment function block has two. There are 4 function blocks, switch signal switching function blocks, and logic blocks respectively. There are two types of logic blocks: 0 logic block and 1 logic block. Their connection relationships include: quality point judgment function block → or function block → non-function block → switch signal switching function block → and function block → or function block → output, temperature measurement point → analog delay function block → difference function block → RS trigger → or function block → non-function block → switch signal switching function block → and function block → or function block → output, temperature measurement point → difference function block → RS trigger → or function block → non-function block → switch signal switching Switch function block → AND function block → OR function block → output, temperature measurement point → upper limit judgment function block → non-function block → RS trigger → OR function block → non-function block → switch signal switching function block → AND function block → OR function block → output, temperature measurement point → upper limit judgment function block → switch signal switching function block → AND function block → OR function block → output, 0 logic block → switch signal switching function block → AND function block → OR function block → output, temperature measurement point → upper limit judgment function block → switch signal switching function block → AND function block → OR function block → output, 1 logic block → switch Switch the signal to the function block → AND function block → OR function block → output; the connection method on the other side is similar to the above connection relationship; set the protection value and alarm value, and verify each other by judging the temperature threshold and quality point of the two monitoring points. When both measuring points are normal, one point reaches the protection value and the other reaches the alarm value, and outputs "1". When there is a bad quality point or the change is too fast, this point is eliminated, and the remaining normal point single measuring point reaches the protection value and outputs "1". When both points are abnormal, output "0". When the output is 1, the protection output is activated and the temperature protection mode is turned on.

[0007] Furthermore, the dual-measurement-point protection macromodule, when in use, calls the dual-measurement-point protection macromodule, the dual-measurement-point protection macromodule lead-out pins are temperature measurement points, a single temperature measurement point can be used alone or two pins can be used simultaneously to verify each other, when a certain temperature measurement point is a bad quality point or the change rate exceeds the limit, the point is removed, and the dual-measurement-point protection macromodule can still achieve the protection value of the remaining temperature measurement points as the judgment condition.

[0008] Furthermore, the difference function block is connected to the temperature value of the analog delay function block and the temperature measuring point, and the temperature values ​​of the two are compared to determine the rate. When the difference change rate between the two is above 8 times / s, it is considered to be a signal failure, that is, the change rate exceeds the limit.

[0009] Furthermore, in the RS trigger, the R terminal triggers logic "1" and the S terminal positions logic "0".

[0010] Furthermore, the upper limit judgment function block has an input data type of analog quantity and an output data type of switch signal. An upper limit parameter is set in the upper limit judgment function block. When the input signal is greater than the set upper limit parameter, the output is 1.

[0011] Furthermore, the upper limit parameter is divided into a protection value and an alarm value, the protection value is greater than the alarm value, and when any normal point reaches the protection value, the alarm value of another point is used as evidence, forming a mutual corroboration working mode.

[0012] Furthermore, the switch signal switching function block outputs the output signal of the upper limit judgment function block when the judgment condition of the non-functional block on the left is logic "1", otherwise it outputs the signal of the logic block, thereby shielding the signal at this point, that is, eliminating the temperature measurement point.

[0013] Furthermore, the connection relationship: temperature measuring point → upper limit judgment functional block → non-functional block → RS trigger → or functional block → non-functional block is a recovery signal line. When the temperature measuring point is eliminated due to the change rate exceeding the limit, after adjustment and repair, the RS trigger is switched through the recovery signal line to release the signal shielding and restore the signal.

[0014] Furthermore, the input signal of the same AND function block is a different switch signal switching module under two temperature measuring points, the alarm value of one temperature measuring point is used as the evidence of the protection value of another temperature measuring point, and the two AND function blocks are output to the same OR function block.

[0015] Furthermore, the dual-measurement-point protection judgment method is completed by configuring the existing functional modules in the current DCS control, and does not need to be formed through high-level language programming.

[0016] The present invention has the following beneficial effects:

[0017] (1) The present invention uses the existing function module configuration in the existing DCS control, and does not need to be formed by high-level language programming. After being packaged into a dual-point protection macro module, it can be called in the same way as a basic function block, and two temperature measurement points and corresponding quality point judgment function blocks are connected and input. After the dual-point protection macro module is used, the output condition is determined. Only the protection value and alarm value of two points need to be set separately on the DCS, and it can be used, which is simple and convenient, and more safe and accurate.

[0018] (2) Compared with the existing single-measurement-point protection module, the present invention adds a measurement point to provide evidence for protection judgment, thereby reducing protection misoperation caused by the temperature of the measurement point; at the same time, the two-point joint judgment avoids the problem of protection refusal to operate in the case of a single measurement point with bad quality;

[0019] (3) The dual-measurement-point protection design of the present invention effectively improves the reliability of temperature protection for important auxiliary machine bearings, avoiding problems such as equipment tripping due to failure of a single measurement point. At the same time, due to the mutual evidence of the dual measurement points, an alarm is given in time when a bad point occurs, and the fault point of the equipment can be found in time, reducing the workload of defect inspection and analysis;

[0020] (4) The present invention can use a single measurement point judgment alone or two pins at the same time to verify each other. When a temperature measurement point is a bad quality point or the change rate exceeds the limit, the point is removed, and the dual-measurement-point protection macro module can still achieve the protection value of the remaining temperature measurement points as the judgment condition; and a built-in recovery signal line is provided. After adjustment and repair, the RS trigger is switched through the recovery signal line to release the signal shielding and restore the signal without affecting the continuous operation.

Brief Description of the Drawings

[0021] Figure 1 It is a configuration diagram of a method for realizing dual-point protection judgment on DCS;

[0022] Figure 2 The invention is a method for realizing double-point protection judgment on DCS, and the principle SAMA diagram.

[0023] The serial numbers in the figure are:

[0024] 01, 02: quality point judgment function block; 03, 04: temperature measurement point; 05, 06: analog delay function block; 07, 08, 09, 10: upper limit judgment function block; 11, 12: difference function block; 13, 14, 27, 28: non-function block; 15, 17: 0 logic block; 16, 18: 1 logic block; 19, 20: RS trigger; 21, 22, 23, 24: switch signal switching function block; 25, 26, 31: or function block; 29, 30: and function block; 32: output. [Specific implementation method]

[0025] In order to better understand the present invention, the present invention is further explained in conjunction with specific implementation methods below. It should be emphasized that the positions of functional blocks appearing in the present invention are based on the actual view positions. The following is merely exemplary and is not intended to limit the scope of the present invention and its application. Any equivalent changes or substitutions made on this basis fall within the protection scope of the present invention.

[0026] A method for realizing dual-point protection judgment on DCS

[0027] like Figure 1 , Figure 2 As shown in the figure, the or function block, the and function block, the non-function block, the quality point judgment function block, the analog delay function block, the difference function block, the RS trigger, the upper limit judgment function block, the switch signal switching function block and the logic block in the DCS system are used to configure the dual-measurement point protection macro command algorithm and package them into a dual-measurement point protection macro module, which can be called in the same way as the basic function block. There are 2 quality point judgment function blocks, 2 analog delay function blocks, 2 difference function blocks and 2 RS triggers respectively, 4 upper limit judgment function blocks, 4 switch signal switching function blocks and 4 logic blocks respectively. There are two types of logic blocks: 0 logic block and 1 logic block. The connection relationship includes:

[0028] Quality point judgment function block 01 → or function block 25 → non-function block 27 → switch signal switching function block 21 → and function block 30 → or function block 31 → output 32,

[0029] Quality point judgment function block 01 → or function block 25 → non-function block 27 → switch signal switching function block 22 → and function block 29 → or function block 31 → output 32,

[0030] Temperature measurement point 03 → analog delay function block 05 → difference function block 11 → RS trigger 19 → or function block 25 → non-function block 27 → switch signal switching function block 21 → and function block 30 → or function block 31 → output 32,

[0031] Temperature measurement point 03 → analog delay function block 05 → difference function block 11 → RS trigger 19 → or function block 25 → non-function block 27 → switch signal switching function block 22 → and function block 29 → or function block 31 → output 32,

[0032] Temperature measurement point 03 → difference function block 11 → RS trigger 19 → or function block 25 → non-function block 27 → switch signal switching function block 21 → and function block 30 → or function block 31 → output 32,

[0033] Temperature measurement point 03 → difference function block 11 → RS trigger 19 → or function block 25 → non-function block 27 → switch signal switching function block 22 → and function block 29 → or function block 31 → output 32,

[0034] Temperature measurement point 03 → upper limit judgment function block 07 → non-function block 13 → RS trigger 19 → or function block 25 → non-function block 27 → switch signal switching function block 21 → and function block 30 → or function block 31 → output 32,

[0035] Temperature measurement point 03 → upper limit judgment function block 07 → non-function block 13 → RS trigger 19 → or function block 25 → non-function block 27 → switch signal switching function block 22 → and function block 29 → or function block 31 → output 32,

[0036] Temperature measurement point 03 → upper limit judgment function block 07 → switch signal switching function block 21 → and function block 30 → or function block 31 → output 32,

[0037] 0 logic block 15 → switch signal switching function block 21 → and function block 30 → or function block 31 → output 32,

[0038] Temperature measurement point 03 → upper limit judgment function block 09 → switch signal switching function block 22 → and function block 29 → or function block 31 → output 32,

[0039] 1 logic block 16 → switch signal switching function block 22 → and function block 29 → or function block 31 → output 32;

[0040] Another temperature measurement point connection relationship: quality point judgment function block 02 → or function block 26 → non-function block 28 → switch signal switching function block 23 → and function block 29 → or function block 31 → output 32,

[0041] Quality point judgment function block 02 → or function block 26 → non-function block 28 → switch signal switching function block 24 → and function block 30 → or function block 31 → output 32,

[0042] Temperature measurement point 04 → analog delay function block 06 → difference function block 12 → RS trigger 20 → or function block 26 → non-function block 28 → switch signal switching function block 23 → and function block 29 → or function block 31 → output 32,

[0043] Temperature measurement point 04 → analog delay function block 06 → difference function block 12 → RS trigger 20 → or function block 26 → non-function block 28 → switch signal switching function block 24 → and function block 30 → or function block 31 → output 32,

[0044] Temperature measurement point 04 → difference function block 12 → RS trigger 20 → or function block 26 → non-function block 28 → switch signal switching function block 23 → and function block 29 → or function block 31 → output 32,

[0045] Temperature measurement point 04 → difference function block 12 → RS trigger 20 → or function block 26 → non-function block 28 → switch signal switching function block 24 → and function block 30 → or function block 31 → output 32,

[0046] Temperature measurement point 04 → upper limit judgment function block 08 → non-function block 14 → RS trigger 20 → or function block 26 → non-function block 28 → switch signal switching function block 23 → and function block 29 → or function block 31 → output 32,

[0047] Temperature measurement point 04 → upper limit judgment function block 08 → non-function block 14 → RS trigger 20 → or function block 26 → non-function block 28 → switch signal switching function block 24 → and function block 30 → or function block 31 → output 32,

[0048] Temperature measurement point 04 → upper limit judgment function block 08 → signal switching function block 23 → and function block 29 → or function block 31 → output 32,

[0049] 0 logic block 17 → semaphore switching function block 23 → AND function block 29 → OR function block 31 → output 32,

[0050] Temperature measurement point 04 → upper limit judgment function block 10 → switch signal switching function block 24 → and function block 30 → or function block 31 → output 32,

[0051] 1 logic block 18 → switch signal switching function block 24 → and function block 30 → or function block 31 → output 32;

[0052] Set the protection value and alarm value in the upper limit judgment function block, and judge the temperature threshold and quality point of the two monitoring points to verify each other. When both measuring points are normal, one point reaches the protection value and the other reaches the alarm value, and outputs "1". When there is a bad quality point or the change is too fast, this point is eliminated, and the remaining normal point reaches the protection value and outputs "1". When both points are abnormal, output "0". When the output is 1, the protection output is activated and the temperature protection mode is turned on.

[0053] like Figure 1 As shown, when using the dual-measurement point protection macro module, the dual-measurement point protection macro module can be called like the basic function block. The dual-measurement point protection macro module leads out the temperature measurement point. A single temperature measurement point can be used alone or two pins can be used at the same time to verify each other. When a temperature measurement point is a bad quality point or the change rate exceeds the limit, the point is removed. The dual-measurement point protection macro module can still realize the protection value of the remaining temperature measurement point as a judgment condition to protect the output action;

[0054] The difference function block is connected to the temperature value of the analog delay function block and the temperature measurement point, and the temperature values ​​of the two are compared to determine the rate. When the rate of change of the difference between the two is more than 8 times / s, it is considered to be a signal failure, that is, the rate of change exceeds the limit;

[0055] RS trigger, R terminal trigger logic "1", S terminal position logic "0", RS trigger cannot pass when the change rate exceeds the limit;

[0056] The upper limit judgment function block has an input data type of analog quantity and an output data type of switch signal. An upper limit parameter is set in the upper limit judgment function block. When the input signal is greater than the set upper limit parameter, the output is 1.

[0057] The upper limit parameter is divided into protection value and alarm value. The protection value is greater than the alarm value, and the upper limit judgment function blocks 07 and 08 are set as protection values, and the upper limit judgment function blocks 09 and 10 are set as alarm values. When any normal point reaches the protection value, the alarm value of the other point is used as evidence to form a mutual evidence working mode. The input signal of the same AND function block is a different switch signal switching module under two temperature measurement points. The alarm value of one temperature measurement point is used as evidence of the protection value of another temperature measurement point. The two AND function blocks output to the same OR function block. When the protection value and the alarm value output under the other temperature measurement point are both 1, "1" is output.

[0058] The switch signal switching function block needs to pass the judgment condition of the non-functional block on the left. When the non-functional block on the left is logical "1", the output signal of the upper limit judgment function block is output, otherwise the signal of the logic block is output. When the output signal is a set fixed signal, it is equivalent to the signal of the upper limit judgment function block at this point is useless, which plays the role of shielding the signal at this point, that is, eliminating the temperature measurement point;

[0059] Connection relationship: temperature measurement point → upper limit judgment function block → non-functional block → RS trigger → or function block → non-functional block, which is the recovery signal line. When the temperature measurement point is removed due to the change rate exceeding the limit, it will be judged as a bad quality point, and the signal of the upper limit judgment function block will be shielded. After adjustment and repair, the RS trigger is switched through the recovery signal line to release the signal shielding and restore the signal;

[0060] The method for double-measurement-point protection judgment is completed by configuring the existing functional modules in the current DCS control without the need for high-level language programming.

[0061] The method of use of the present invention is:

[0062] Set the protection value and alarm value in the upper limit judgment function block under the two temperature measurement points, select the position to install the two quality point judgment function blocks and the two temperature measurement points, first use the quality point judgment function block to judge whether the point is a bad quality point, then the temperature measurement point passes through the analog delay function block and the difference function block to judge whether the change rate exceeds the limit, if there is no bad quality point and the change rate exceeds the limit, then through the or function block and the non-function block, the non-function block outputs logic "1" to the switch signal switching function block, then the switch signal switching function block outputs the signal according to the upper limit judgment function block to the corresponding and function block, the protection value under one temperature measurement point is supported by the alarm value under the other temperature measurement point, the signals of the two and function blocks are summarized in the or function block 31, one point reaches the protection value and the other reaches the alarm value, and outputs "1";

[0063] If a bad quality point appears at one of the points or the rate of change exceeds the limit, the OR function block 25 or the OR function block 26 will not pass, and the corresponding non-functional block does not output logic "1" to the switch signal switching function block. The switch signal switching function block outputs the signal in the corresponding connected logic block, and the signal of this point is shielded, that is, the point is eliminated. If another normal point reaches the protection value at this time, it is similar to the above signal output. The corresponding AND function block outputs a signal "1", and the other AND function block outputs a signal "0". After passing through the OR function block 31, it outputs "1", and the protection judgment can be achieved when reaching a single measuring point; if a bad quality point appears, it should be repaired as soon as possible. If the rate of change exceeds the limit, after eliminating the problem and performing maintenance, the signal is restored through the temperature measuring point → upper limit judgment function block → non-functional block → RS trigger → OR function block → non-functional block. After recovery, the upper limit judgment function block does not output "1", but after passing through the non-functional block, it outputs "1" to trigger the RS trigger and restore the signal;

[0064] When both points are abnormal, the output is "0".

[0065] The double-measurement-point protection judgment method can be used on bearings of blowers, induced draft fans, primary fans, small machines, pre-pumps, etc. After being modified by the method of the present invention, the double-measurement-point protection judgment method is applied, the use effect is good, and the reliability of the equipment is effectively improved.

[0066] The above content cannot be used to determine that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the concept of the present invention, which should be regarded as belonging to the scope of patent protection of the present invention determined by the submitted claims.

Claims

1. A method for realizing dual-point protection judgment on DCS, characterized in that: By using the OR function block, AND function block, NON function block, quality point judgment function block, analog delay function block, difference function block, RS trigger, upper limit judgment function block, switch signal switching function block and logic block in the DCS system, the dual-measurement point protection macro command algorithm is configured and packaged into a dual-measurement point protection macro module, which can be called in the same way as the basic function block when used. The quality point judgment function block, analog delay function block, difference function block and RS trigger are respectively 2, the upper limit judgment function block, switch signal switching function block and logic block are respectively 4, and there are two types of logic blocks, namely 0 logic block and 1 logic block, and the connection relationship includes: quality point judgment function block → OR function block → NON function block → switch signal switching function block → AND function block → OR function block → output, temperature measurement point → analog delay function block → difference function block → RS trigger → OR function block → NON function block → switch signal switching function block → AND function block → OR function block → output, temperature measurement point → difference function block → RS trigger → OR function block → NON function block Block → switch signal switching function block → AND function block → OR function block → output, temperature measuring point → upper limit judgment function block → non-function block → RS trigger → OR function block → non-function block → switch signal switching function block → AND function block → OR function block → output, temperature measuring point → upper limit judgment function block → switch signal switching function block → AND function block → OR function block → output, 0 logic block → switch signal switching function block → AND function block → OR function block → output, 1 logic block → switch signal switching function block → AND function block → OR function block → output; The connection method on the other side is similar to the above connection relationship; set the protection value and alarm value, and verify each other by judging the temperature threshold and quality point of the two monitoring points. When both measuring points are normal, one point reaches the protection value and the other reaches the alarm value, and outputs "1". When one point has a bad quality point or changes too fast, this point is eliminated. The remaining normal point single measuring point reaches the protection value and outputs "1". When both points are abnormal, output "0". When the output is 1, the protection output is activated and the temperature protection mode is turned on. The difference function block is connected to the temperature value of the analog delay function block and the temperature measuring point, and the temperature values ​​of the two are compared to determine the rate. When the rate of change of the difference between the two is more than 8 times / s, it is considered to be a signal failure, that is, the rate of change exceeds the limit; The upper limit judgment function block has an input data type of analog quantity and an output data type of switch signal. An upper limit parameter is set in the upper limit judgment function block. When the input signal is greater than the set upper limit parameter, the output is 1; The upper limit parameter is divided into a protection value and an alarm value. The protection value is greater than the alarm value. When any normal point reaches the protection value, the alarm value of another point is used as evidence to form a mutual evidence working mode. The switch signal switching function block outputs the output signal of the upper limit judgment function block when the judgment condition of the non-functional block on the left is logic "1", otherwise it outputs the signal of the logic block, which plays the role of shielding the signal of the point, that is, eliminating the temperature measurement point; The connection relationship: temperature measuring point → upper limit judgment functional block → non-functional block → RS trigger → or functional block → non-functional block is a recovery signal line. When the temperature measuring point is eliminated due to the change rate exceeding the limit, after adjustment and repair, the RS trigger is switched through the recovery signal line to release the signal shielding and restore the signal.

2. A method for realizing dual-point protection judgment on DCS according to claim 1, characterized in that: The dual-measurement-point protection macromodule, when in use, calls the dual-measurement-point protection macromodule, the dual-measurement-point protection macromodule leads out pins as temperature measurement points, a single temperature measurement point can be used alone or two pins can be used simultaneously to verify each other, when a certain temperature measurement point is a bad quality point or the change rate exceeds the limit, the point is removed, and the dual-measurement-point protection macromodule can still realize the protection value of the remaining temperature measurement points as the judgment condition.

3. A method for realizing dual-point protection judgment on DCS according to claim 1, characterized in that: For the RS flip-flop, the R terminal triggers logic "1" and the S terminal positions logic "0".

4. A method for realizing dual-point protection judgment on DCS according to claim 1, characterized in that: The dual-measurement-point protection judgment method is completed by configuring the existing function modules in the current DCS control, and does not need to be formed by high-level language programming.

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