Wall temperature uniformity detection method and device for membrane water wall of power station boiler

Abstract

The invention discloses a wall temperature uniformity detection method and device for a membrane type water cooling wall of a power station boiler. The method comprises the following steps: determining the distance between water cooling wall tubes i and j specified by the membrane type water cooling wall; respectively acquiring temperatures detected by the temperature sensors of the water wall tubes i and j; the wall temperature uniformity index of the membrane type water cooling wall is calculated according to the # imgabs0, the # imgabs1 # is the wall temperature uniformity index of the membrane type water cooling wall, the # imgabs2 # is the temperature of the water cooling wall tubes i and j, the temperature difference of the water cooling wall tubes i and j is calculated, the # imgabs3 # is the distance between the water cooling wall tubes i and j, the # imgabs4 # is included, the # imgabs5 # is the temperature of the water cooling wall tube i, and the # imgabs6 # is the temperature of the water cooling wall tube j. The method aims at solving the problem that an existing wall temperature uniformity detection method does not consider the distance between two points, so that the accuracy is not high, the objectivity of water cooling wall safety evaluation is improved, and a basis is provided for evaluation of unit peak regulation flexibility.

Description

Technical Field

[0001] The invention relates to the field of power station boiler wall temperature monitoring, and in particular to a method and a device for detecting the wall temperature uniformity of a membrane water-cooled wall of a power station boiler. Background Art

[0002] The membrane water-cooled wall is the main component of the power plant boiler. It plays the role of converting the heat generated by the combustion of fuel into the internal energy of the working fluid. Its working mode is to absorb heat from the flue gas side and then transfer the heat to the working fluid. The relationship between the heat absorbed by the water-cooled wall and the heat released determines its temperature level. In addition to the temperature, the temperature distribution of the water-cooled wall is also an important information that operators pay attention to, which is determined by the inherent structure of the membrane water-cooled wall. The membrane water-cooled wall is composed of multiple water-cooled wall tubes connected side by side by fins. Since the flow rate of the working fluid flowing through each water-cooled wall tube is not the same, and the heat difference on the flue gas side is superimposed, the temperature of the membrane water-cooled wall tube has a temperature deviation. The thermal expansion difference caused by the temperature deviation will produce thermal stress. When the thermal stress exceeds the allowable value of the material, it will cause the water-cooled wall tube to crack and leak, endangering the safe operation of the boiler. In new power systems, peak-shaving operation of thermal power units has become the norm. During low load or rapid load changes, the working state of the water-cooled wall deviates from the design value, the hydrodynamic stability is poor, and the thermal load deviation on the flue gas side increases. In addition to wall temperature exceeding the limit, wall temperature uniformity is another major factor limiting the peak-shaving operation of the unit.

[0003] At present, the temperature uniformity of the water-cooled wall is usually directly characterized by the temperature deviation between two points. However, since the thermal stress between the membrane water-cooled walls is related to the temperature deviation and the distance between the locations where the temperature deviation exists, the greater the temperature deviation, the smaller the distance, and the greater the thermal stress. Since the distance between two points is not considered in the current evaluation of the temperature uniformity of the water-cooled wall, there is a problem of poor accuracy, which affects the safety of boiler operation. Summary of the invention

[0004] Technical problem to be solved by the present invention: In view of the above-mentioned problems in the prior art, a method and device for detecting the wall temperature uniformity of a membrane water-cooled wall of a power station boiler are provided. The present invention aims to solve the problem that the existing wall temperature uniformity detection method does not take into account the distance between two points, resulting in low accuracy, improve the objectivity of the water-cooled wall safety evaluation, and provide a basis for the evaluation of the peak-shaving flexibility of the unit.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for detecting the uniformity of the wall temperature of a membrane water-cooled wall of a power station boiler comprises the following steps: S1, determine the water-cooled wall tubes specified for the membrane water-cooled wall i and j The distance between S2, respectively obtain the water-cooled wall tubei and j The temperature detected by the temperature sensor; S3, calculate the wall temperature uniformity index of the membrane water-cooled wall according to the following formula: , In the above formula, It is the temperature uniformity index of the membrane water-cooled wall. Water-cooled wall tube i and j Temperature calculation of water wall tubes i and j The temperature difference, Water-cooled wall tube i and j The distance between them is: , In the above formula, Water-cooled wall tube i The temperature, Water-cooled wall tube j temperature.

[0006] Optionally, the water-cooled wall tube i and j The calculation function expression of the distance between is: , In the above formula, Water-cooled wall tube i and j The distance between Water-cooled wall tube i The distance to the origin, Water-cooled wall tube j The distance to the origin, where the origin is the water-cooled wall tube i and j The specified position point in the direction of the connection line.

[0007] Optionally, the membrane water-cooled wall is composed of a plurality of water-cooled wall tubes arranged in parallel and connected by fins between adjacent water-cooled wall tubes. The temperature sensor is installed at the midpoint of the fin corresponding to the water-cooled wall tube and is at an equal distance from the water-cooled wall tubes on both sides. The temperature sensor is installed on the back-fire side of the fin corresponding to the water-cooled wall tube.

[0008] Optionally, before step S1, simulation is performed to determine the temperature measurement points of the water-cooled wall tubes and to install temperature sensors: S101, simulating the power plant boiler and obtaining the temperature field of the membrane water-cooled wall cross section; S102, finding the highest temperature point on the back-fire side of the membrane water-cooled wall cross section in the temperature field as the temperature measurement point of the water-cooled wall tube; S103, installing a temperature sensor at the temperature measuring point.

[0009] Optionally, installing the temperature sensor at the temperature measurement point in step S103 includes: selecting a temperature sensor model with the smallest size from a plurality of available temperature sensor models and installing the temperature sensor at the temperature measurement point.

[0010] Optionally, after calculating the wall temperature uniformity index of the membrane water-cooled wall in step S3, it also includes judging whether the wall temperature uniformity index of the membrane water-cooled wall exceeds a preset threshold value. If it exceeds the preset threshold value, the peak-shaving operation of the generator set corresponding to the power plant boiler is restricted.

[0011] In addition, the present invention also provides a wall temperature uniformity detection device for a membrane water-cooled wall of a power station boiler, comprising a temperature detection unit and a detection terminal device connected to each other, wherein the temperature detection unit comprises a temperature sensor corresponding to the fins corresponding to the water-cooled wall tubes or a temperature sensor arranged at intervals of a specified number of fins, and the temperature sensor is installed on the back-fire side of the fin, and the detection terminal device comprises a microprocessor and a memory connected to each other, and the microprocessor is programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler.

[0012] In addition, the present invention also provides a wall temperature uniformity detection device for a membrane water-cooled wall of a power station boiler, comprising an interconnected microprocessor and a memory, wherein the microprocessor is programmed or configured to execute the wall temperature uniformity detection method for a membrane water-cooled wall of a power station boiler.

[0013] In addition, the present invention also provides a computer-readable storage medium, which stores a computer program or instruction, and the computer program or instruction is programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler through a processor.

[0014] In addition, the present invention also provides a computer program product, including a computer program or instructions, which are programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler through a processor.

[0015] Compared with the prior art, the present invention has the following advantages: the method of the present invention uses the wall temperature deviation per unit distance as the wall temperature uniformity index to evaluate the uniformity of the water-cooled wall temperature distribution on the same side of the power station boiler, including determining the water-cooled wall tubes specified by the membrane water-cooled wall i and j The distance between the water-cooled wall tubes i and j The temperature detected by the temperature sensor; The wall temperature uniformity index of the membrane water-cooled wall is calculated. The present invention incorporates the distance factor between the temperature deviations into the evaluation scope of the wall temperature uniformity, which can solve the problem of low accuracy caused by the existing wall temperature uniformity detection method not considering the distance between two points, improve the objectivity of the water-cooled wall safety evaluation, and provide a basis for the evaluation of the peak-shaving flexibility of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the basic flow of the method of the embodiment of the present invention.

[0017] Figure 2 The water-cooled wall tube in the embodiment of the present invention i and j Schematic diagram of the positional relationship between them.

[0018] Figure 3 The water-cooled wall tube in the embodiment of the present invention i and j Schematic diagram of location selection.

[0019] Figure 4 Schematic diagram of the installation structure of the temperature sensor in the embodiment of the present invention.

[0020] Figure 5 : is the temperature field of the cross section of the membrane water-cooled wall obtained by simulation in the embodiment of the present invention. DETAILED DESCRIPTION

[0021] like Figure 1 As shown, the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler in this embodiment includes the following steps: S1, determine the water-cooled wall tubes specified for the membrane water-cooled wall i and j The distance between S2, respectively obtain the water-cooled wall tube i and j The temperature detected by the temperature sensor; S3, calculate the wall temperature uniformity index of the membrane water-cooled wall according to the following formula: , In the above formula, It is the temperature uniformity index of the membrane water-cooled wall. Water-cooled wall tube i and j Temperature calculation of water wall tubes i and j The temperature difference, Water-cooled wall tube i and j The distance between them is: , In the above formula, Water-cooled wall tube i The temperature, Water-cooled wall tube j In this embodiment, the wall temperature deviation per unit distance is used as the wall temperature uniformity index to evaluate the uniformity of the wall temperature distribution of the water-cooled wall on the same side of the power station boiler.

[0022] Determine the water wall tubes specified for membrane water wall i and j The distance between the water-cooled wall tubes can be determined according to actual needs. For example, as an optional embodiment, the water-cooled wall tubes in this embodiment are i and j The calculation function expression of the distance between is: , In the above formula, Water-cooled wall tube i and j The distance between Water-cooled wall tube i The distance to the origin, Water-cooled wall tube j The distance to the origin, where the origin is the water-cooled wall tube i and j The origin position selection may involve a negative distance calculation result. If it is a negative value, the absolute value needs to be taken (because the distance is a positive value). Figure 2 As shown, It can represent water-cooled wall tube i and j In this embodiment, the water-cooled wall tubes of the membrane water-cooled wall are numbered 1 to n in sequence starting from one side, and the corresponding serial numbers of each water-cooled wall tube are 1 to n, and the corresponding temperatures are T1 to T2 respectively. n , and the corresponding distances are ~ , water wall tube i and j The serial number can be selected as needed within the above range (i is not equal to j), for example, as an optional implementation, Figure 3 As shown, in this embodiment i= 1, j = n, that is, the two outermost water-cooled wall tubes of the membrane water-cooled wall are taken as water-cooled wall tubes i and j Therefore, when evaluating the wall temperature deviation of the water-cooled wall, the wall temperature difference between the first and n points is calculated. , and distance , then the unit distance wall temperature deviation between the two points is: .

[0023] like Figure 3 and Figure 4 As shown, the membrane water-cooled wall in this embodiment is composed of a plurality of water-cooled wall tubes a arranged in parallel and connected by fins b between adjacent water-cooled wall tubes, and the temperature sensor c is installed at the midpoint of the fin b corresponding to the water-cooled wall tube a and is at an equal distance from the water-cooled wall tubes a on both sides, and the temperature sensor c is installed on the back-fire side of the fin b corresponding to the water-cooled wall tube a. Among them, the corresponding relationship between the water-cooled wall tube a and the fin b can be specified according to actual needs as the fin b on one side of the water-cooled wall tube a is the fin b corresponding to the water-cooled wall tube a. Figure 4 In the middle, d is a fastener (bolt) used to install fin b, which is also installed at the midpoint of fin b corresponding to water-cooled wall tube a and is equidistant from water-cooled wall tube a on both sides.

[0024] In addition, before step S1 of this embodiment, simulation is performed to determine the temperature measurement points of the water-cooled wall tubes and to install temperature sensors: S101, simulating the power plant boiler and obtaining the temperature field of the membrane water-cooled wall cross section; S102, finding the highest temperature point on the back-fire side of the membrane water-cooled wall cross section in the temperature field as a temperature measurement point of the water-cooled wall tube; S103, installing a temperature sensor at the temperature measuring point.

[0025] The simulation of the power plant boiler in step S101 is a basic thermal simulation. The simulation software and its application method can be used as needed. This embodiment is only an application of the above basic thermal simulation method, so its implementation details are not described in detail here. In this embodiment, the power plant boiler is simulated and the temperature field of the membrane water wall cross section is obtained. Figure 5 See Figure 5 It can be seen that the temperature of the water-cooled wall tubes and fins on the cross section has certain distribution characteristics. The highest temperature point will appear at the top of the fire-facing side or the midpoint of the fin according to the size of the fin, and the temperature difference between the highest and lowest temperature points can reach 20~30℃. Since the top of the fire-facing side faces the high-temperature flue gas in the furnace, it is not convenient for installation and maintenance. The traditional temperature measurement method usually installs the wall temperature measurement point at the top of the back-fire side tube. The measured temperature is the lowest temperature point of the tube and the fin on the cross section, which is difficult to truly reflect the tube wall temperature. Therefore, in this embodiment, the highest temperature point is found on the back-fire side of the membrane water-cooled wall cross section in the temperature field as the temperature measurement point of the water-cooled wall tube. Compared with the traditional wall temperature measurement method, the method of this embodiment focuses on the accuracy of temperature measurement, fully considers the temperature distribution of the water-cooled wall tube and the fin on the cross section, and accurately measures the temperature value of the corresponding position on the water-cooled wall tube. The installation position is at the midpoint of the fin, the temperature is higher, and it can more truly reflect the water-cooled wall temperature level.

[0026] In step S103 of this embodiment, installing a temperature sensor at the temperature measuring point includes: selecting a temperature sensor model with the smallest size from a plurality of available temperature sensor models and installing it at the temperature measuring point, and by using a temperature measuring element with a smaller size, the temperature value at the corresponding position on the water-cooled wall tube can be accurately measured.

[0027] After calculating the wall temperature uniformity index of the membrane water-cooled wall in step S3 of this embodiment, it also includes judging whether the wall temperature uniformity index of the membrane water-cooled wall exceeds a preset threshold value. If it exceeds the preset threshold value, the peak-shaving operation of the generator set corresponding to the power station boiler is restricted.

[0028] In summary, the method of this embodiment measures the temperature value on the fins of the water-cooled wall tubes, and uses the ratio of the temperature difference between any two measuring points to the distance between the two measuring points to evaluate the uniformity of the wall temperature distribution. The method of this embodiment incorporates the distance factor between the temperature deviations into the evaluation scope of the wall temperature uniformity, which can solve the problem that the existing wall temperature uniformity detection method does not consider the distance between the two points, resulting in low accuracy, improve the objectivity of the water-cooled wall safety evaluation, and provide a basis for the evaluation of the unit's peak-shaving flexibility. Moreover, when measuring the wall temperature uniformity detection method of the membrane water-cooled wall of a power station boiler in this embodiment, by optimizing the temperature measurement points, it can better reflect the level of the wall temperature, and can also more realistically and objectively reflect the stress caused by the temperature deviation, thereby providing a unified standard for the evaluation of the wall temperature deviation of power station boilers of different sizes.

[0029] In addition, this embodiment also provides a wall temperature uniformity detection device for a membrane water-cooled wall of a power station boiler, comprising a temperature detection unit and a detection terminal device connected to each other, wherein the temperature detection unit comprises a temperature sensor corresponding to a fin corresponding to the water-cooled wall tube or a temperature sensor arranged at intervals of a specified number of fins, and the temperature sensor is installed on the back-fire side of the fin, and the detection terminal device comprises a microprocessor and a memory connected to each other, and the microprocessor is programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler.

[0030] In addition, this embodiment also provides a wall temperature uniformity detection device for a membrane water-cooled wall of a power station boiler, comprising a microprocessor and a memory connected to each other, wherein the microprocessor is programmed or configured to execute the wall temperature uniformity detection method for a membrane water-cooled wall of a power station boiler.

[0031] In addition, this embodiment also provides a computer-readable storage medium, which stores a computer program or instruction, and the computer program or instruction is programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power plant boiler through a processor.

[0032] In addition, this embodiment also provides a computer program product, including a computer program or instructions, which are programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler through a processor.

[0033] Those skilled in the art should understand that the technical solutions provided by the embodiments of the present application may be in the form of methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the functions specified in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0034] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for detecting the uniformity of the wall temperature of a membrane water-cooled wall of a power station boiler, characterized in that: The steps include: S1, determine the water-cooled wall tubes specified for the membrane water-cooled wall i and j The distance between S2, respectively obtain the water-cooled wall tube i and j The temperature detected by the temperature sensor; S3, calculate the wall temperature uniformity index of the membrane water-cooled wall according to the following formula: ， In the above formula, It is the temperature uniformity index of the membrane water-cooled wall. Water-cooled wall tube i and j Temperature calculation of water wall tubes i and j The temperature difference, Water-cooled wall tube i and j The distance between them is: ， In the above formula, Water-cooled wall tube i The temperature, Water-cooled wall tube j temperature.

2. The method for detecting the wall temperature uniformity of a membrane water-cooled wall of a power station boiler according to claim 1, characterized in that: The water-cooled wall tube i and j The calculation function expression of the distance between is: ， In the above formula, Water-cooled wall tube i and j The distance between Water-cooled wall tube i The distance to the origin, Water-cooled wall tube j The distance to the origin, where the origin is the water-cooled wall tube i and j The specified position point in the direction of the connection line.

3. The method for detecting the wall temperature uniformity of a membrane water-cooled wall of a power station boiler according to claim 1, characterized in that: The membrane water-cooled wall is composed of a plurality of water-cooled wall tubes arranged in parallel and connected by fins between adjacent water-cooled wall tubes. The temperature sensor is installed at the midpoint of the fin corresponding to the water-cooled wall tube and is at an equal distance from the water-cooled wall tubes on both sides. The temperature sensor is installed on the back-fire side of the fin corresponding to the water-cooled wall tube.

4. The method for detecting the uniformity of the wall temperature of the membrane water-cooled wall of a power station boiler according to claim 3 is characterized in that: Before step S1, simulation is performed to determine the temperature measurement points of the water-cooled wall tubes and to install temperature sensors: S101, simulating the power plant boiler and obtaining the temperature field of the membrane water-cooled wall cross section; S102, finding the highest temperature point on the back-fire side of the membrane water-cooled wall cross section in the temperature field as a temperature measurement point of the water-cooled wall tube; S103, installing a temperature sensor at the temperature measuring point.

5. The method for detecting the wall temperature uniformity of a membrane water-cooled wall of a power station boiler according to claim 4, characterized in that: Installing the temperature sensor at the temperature measuring point in step S103 includes: selecting a temperature sensor model with the smallest size from among the available multiple temperature sensor models and installing it at the temperature measuring point.

6. The method for detecting the wall temperature uniformity of a membrane water-cooled wall of a power station boiler according to claim 1, characterized in that: After calculating the wall temperature uniformity index of the membrane water-cooled wall in step S3, it also includes judging whether the wall temperature uniformity index of the membrane water-cooled wall exceeds a preset threshold value. If it exceeds the preset threshold value, the peak-shaving operation of the generator set corresponding to the power plant boiler is restricted.

7. A wall temperature uniformity detection device for a membrane water-cooled wall of a power station boiler, characterized in that: It comprises a temperature detection unit and a detection terminal device which are interconnected, wherein the temperature detection unit comprises temperature sensors which correspond one to one with the fins corresponding to the water-cooled wall tubes or temperature sensors which are arranged at intervals of a specified number of fins, and the temperature sensors are installed on the back-fire side of the fins, and the detection terminal device comprises a microprocessor and a memory which are interconnected, and the microprocessor is programmed or configured to execute the wall temperature uniformity detection method for the membrane water-cooled wall of a power station boiler as described in any one of claims 1 to 6.

8. A device for detecting the uniformity of the wall temperature of a membrane water-cooled wall of a power station boiler, comprising a microprocessor and a memory connected to each other, characterized in that: The microprocessor is programmed or configured to execute the wall temperature uniformity detection method for a membrane water-cooled wall of a power station boiler as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program or instruction stored therein, characterized in that: The computer program or instruction is programmed or configured to execute the wall temperature uniformity detection method for a membrane water-cooled wall of a power station boiler as described in any one of claims 1 to 6 through a processor.

10. A computer program product comprising a computer program or instructions, characterized in that The computer program or instruction is programmed or configured to execute the wall temperature uniformity detection method for a membrane water-cooled wall of a power station boiler as described in any one of claims 1 to 6 through a processor.

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