Industrial crystallization deposition on-line monitoring device and method

Abstract

The application discloses an industrial crystallization deposition online monitoring device and method, and relates to the technical field of industrial crystallization deposition online monitoring, and can realize direct monitoring of crystallization deposition conditions of industrial pipelines and equipment, effectively improve pipeline equipment operation safety, and reduce pipeline equipment maintenance costs. The online monitoring device comprises a real-time monitoring system, an external circulation system and a data processing system, and a crystallization fouling thickness calculation method comprises the following steps: collecting working condition data of a pipeline in an actual operation process, forming an initial data set of pipeline working conditions, carrying out pretreatment to obtain a pretreatment database; measuring the inner and outer surface temperatures of an inner probe under a non-fouling state and working conditions; calculating heat transfer coefficients of the measuring points of the inner probe under the non-fouling state and the fouling state; calculating fouling thermal resistances after crystallization, and calculating the fouling thicknesses of the outer surfaces of the inner probe at six measuring points by using the fouling thermal resistances; and calculating the crystallization thicknesses of the outer surfaces of the inner probe in three radial directions. The online monitoring device can realize direct monitoring of crystallization deposition conditions of industrial pipelines and equipment, effectively improve pipeline equipment operation safety, and reduce pipeline equipment maintenance costs.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical industry special pipe equipment crystallization corrosion failure protection, and particularly relates to an industrial crystallization deposition online monitoring device and method. BACKGROUND

[0002] Crystallization and particle deposition are basic physical processes, which play an important role in many disciplines, such as materials, chemical industry, aerospace, energy and environmental science. In chemical production systems, many corrosive substances will gradually cool down and crystallize into particles when flowing in the pipeline. These particles flow with the fluid in the pipeline to form a three-phase fluid, and often deposit on the pipe wall, causing pipe blockage and deposition corrosion problems, which seriously affect the long-term safe operation of chemical equipment and the safety production of enterprises.

[0003] To cope with the problem of intensified crystallization, the current domestic and foreign solutions include water injection and improvement of pipeline surface treatment process to reduce crystallization pollution and corrosion failure; selection of corrosion-resistant materials; control of the content of relevant elements in the working fluid; and ceramic coating spraying

[0004] The above solutions mainly focus on the mitigation measures of crystallization pollution and the prediction of pollution deposition position, and it is difficult to know the crystallization condition in the pipeline. Although process simulation software can simulate the crystallization condition of the pipeline and heat exchange equipment, it is not time-effective and has a large gap with the actual working condition. Therefore, it is particularly important to monitor the operation condition of the pipeline equipment in real time and feed back to the staff to respond in time. However, through the search, there is still a lack of real-time monitoring technology for the amount of crystallization in the pipeline. SUMMARY

[0005] The present application aims to solve the problem of real-time monitoring of the amount of crystallization in the pipeline which is currently lacking. The reliable industrial crystallization deposition online monitoring device and method provided by the present application can solve the problems mentioned in the background. The technical purposes to be solved by the present application include two, the first purpose is to provide an industrial crystallization deposition online monitoring device, and the second purpose is to provide a reliable crystallization fouling thickness calculation method.

[0006] In order to solve the above technical problems, the following technical solutions are adopted:

[0007] The utility model provides an industrial crystallization deposition on -line monitoring device, its characterized in be: the device includes real -time monitoring system, external circulation system and data processing system, real -time monitoring system includes the inner tube, thermocouple and temperature detection meter, the inner tube inserts into the pipeline, thermocouple is arranged on the outer wall of the inner tube, and it is used to detect the temperature of the outer wall of the inner tube, temperature detection meter is used to detect the inflow temperature and outflow temperature of the cold fluid of the inner tube and the inflow temperature and outflow temperature of the hot fluid of the pipeline, external circulation system is used to provide circulating constant temperature cold fluid to the inner tube, data processing system connects thermocouple and temperature detection meter, and the crystallization thickness of the surface of the inner tube is calculated according to the temperature of the outer wall of the inner tube, the inflow and outflow temperature of hot fluid, the inflow and outflow temperature of cold fluid.

[0008] Further, the thermocouple of the inner tube is provided with six, which are arranged in turn on the hot flow surface and the back hot flow surface of the inner tube from top to bottom.

[0009] Further, the external circulation system includes a circulating pipeline, a pump, a mass flow meter and a constant temperature water tank connected to the circulating pipeline, the inflow end and the outflow end of the circulating pipeline are connected to the inner tube, for circulating constant temperature cold fluid to the inner tube, the temperature detection meter includes a first temperature detection meter and a second temperature detection meter, the first temperature detection meter is arranged at the inflow end of the circulating pipeline for detecting the inflow temperature of the cold fluid, the second temperature detection meter is arranged at the outflow end of the circulating pipeline for detecting the outflow temperature of the cold fluid, the temperature detection meter further includes a third temperature detection meter and a fourth temperature detection meter, the third temperature detection meter is used to detect the inflow temperature of the hot fluid in the pipeline, and the fourth temperature detection meter is used to detect the outflow temperature of the hot fluid in the pipeline, the mass flow meter is arranged at the inflow end of the circulating pipeline for detecting the real-time mass flow of the cold fluid.

[0010] Further, the data processing system includes a signal transmission line and a controller, the signal transmission line connects the controller with the thermocouple, the temperature detection meter and the mass flow meter, the controller includes a data acquisition module and a data analysis module, the data acquisition module connects the thermocouple, the temperature detection meter and the mass flow meter, and acquires the temperature of the outer wall of the inner tube, the inflow and outflow temperature of hot fluid, the inflow and outflow temperature of cold fluid and the real-time mass flow of cold fluid, and the data analysis module calculates the crystallization thickness of the outer wall of the inner tube according to the acquired temperature of the outer wall of the inner tube, the inflow and outflow temperature of hot fluid, the inflow and outflow temperature of cold fluid and the mass flow of cold fluid.

[0011] A crystallization dirt thickness calculation method, characterized by comprising the following steps:

[0012] S1: the data processing system acquires the following data and constructs a database:

[0013] The pipeline temperature detector distributed in the external circulation system collects the real-time inflow temperature T of the cold fluid l，in and the real-time outflow temperature T l，out ;

[0014] The pipeline temperature detector distributed in the external circulation system collects the real-time inflow temperature T of the cold fluid r，in and the real-time outflow temperature T r，out ;

[0015] The six thermocouples distributed in the inner tube measure the real-time temperature T' of the outer wall surface in the non-scaling state after removing scaling out1 ~ T' out 6 ;

[0016] The six thermocouples distributed in the inner tube measure the real-time temperature T of the outer wall surface in the scaling state out 1 ~ T out 6 ;

[0017] The mass flow meter distributed in the external circulation system collects the real-time mass flow q of the cold fluid inflow ml .

[0018] S2: Calculate the real-time temperature T' of the inner wall surface of the six measuring points of the inner tube in the non-scaling state in1 ~ T' in6 ; Calculate the real-time temperature T of the inner wall surface of the six measuring points of the inner tube in the scaling state in 1~ T in 6 . And record in the database. The calculation formula is as follows:

[0019]

[0020] Where k represents the six measuring points, k ∈ [1, 6];

[0021] T' out k is the real-time temperature of the outer wall surface of the six measuring points of the inner tube in the non-scaling state obtained from S1;

[0022] T out k is the real-time temperature of the outer wall surface of the six measuring points of the inner tube in the scaling state obtained from S1;

[0023] δ w is the thickness of the inner tube wall; λ w is the thermal conductivity of the inner tube;

[0024] q' is the average heat flux density through the inner tube wall in the non-scaling state;

[0025] q w is the average heat flux density through the inner tube wall in the scaling state.

[0026] The average heat flux density q of the cold fluid passing through the inner tube wall can be calculated by the following formula:

[0027]

[0028] Among them, the heat transfer through the inner tube wall Q w Equal to the heat exchange of cold fluid Q l , A l Is the heat transfer area of ​​the cold fluid. The heat transfer capacity of the cold fluid Q l Heat exchange area with cold fluid A l The calculation formulas are:

[0029] Q l =C l q m,1 (T l，out -T l，in )

[0030] A l =d in πl

[0031] Among them C l and q m , 1 is the specific heat and mass flow rate of the cold fluid;

[0032] T l，out and T l，in are the outflow and inflow temperatures of the cold fluid, respectively.

[0033] di n is the inner wall diameter of the inner tube, and l is the length of the inner tube inserted into the pipeline.

[0034] S3: Calculate the local heat transfer coefficients h′1 to h′6 at the six measuring points of the inner tube under the non-scaling state. The calculation formula is:

[0035]

[0036] Among them, k represents 6 measurement points, k∈[1,6];

[0037] T r，in is the inflow temperature of the thermal fluid;

[0038] T′ out k is the outer wall temperature of the inner tube at six measuring points in the non-scaling state;

[0039] q′ w is the heat flux density in the non-scaling state.

[0040] S4: Calculate the local heat transfer coefficients h1~h6 at the six measuring points of the inner tube under the fouling state. The calculation formula is:

[0041]

[0042] where k represents the 6 measuring points, k∈[1, 6];

[0043] T r，in is the inflow temperature of the hot fluid;

[0044] q w is the average heat flux density in the fouling state;

[0045] T out k is the outer wall surface temperature of the 6 measuring points of the inner tube in the fouling state.

[0046] S5: Calculate the fouling resistance R f,1 ~R f,6 of the 6 measuring points, and calculate the fouling thickness 61~66 of the outer wall surface of the 6 measuring points of the inner tube. The calculation formula is as follows:

[0047]

[0048]

[0049] δ k =r3-r2

[0050] where k represents the 6 measuring points, k∈[1, 6];

[0051] C l and q ml are the specific heat and mass flow of the cold fluid;

[0052] l is the length of the inner tube inserted into the pipeline;

[0053] r1, r2 and r3 are the inner radius, outer radius and radius including fouling thickness of the inner tube, respectively;

[0054] h′ k is the local heat transfer coefficient of the 6 measuring points of the inner tube in the clean state;

[0055] h k is the local heat transfer coefficient of the 6 measuring points of the inner tube in the fouling state;

[0056] λ f is the fouling thermal conductivity.

[0057] S6: Calculate the crystalline thickness difference of the inner tube in 3 radial directions respectively, and the calculation formula is as follows: the fouling thickness δ t1 ~δ t6 of the outer wall surface of the 6 measuring points obtained from step S5 is calculated according to the following formula:

[0058] δ=δ k -δk+3

[0059] The thickness of the three radial direction crystallization of the interpolation tube is obtained, wherein k is in [1, 3].

[0060] The heat flow surface and the back heat flow surface of the interpolation tube are arranged with three thermocouples from top to bottom, respectively, six thermocouples are combined two by two, the first thermocouple is combined with the fourth thermocouple, the second thermocouple is combined with the fifth thermocouple, and the third thermocouple is combined with the sixth thermocouple, to measure the data of the three radial directions of the interpolation tube, respectively; wherein the first, second and third are arranged on the heat flow surface of the interpolation tube, and the fourth, fifth and sixth are arranged on the back heat flow surface of the interpolation tube.

[0061] The inflow temperature of the heat fluid in the steps S3 and S4 can be obtained by the average temperature T r，av Alternatively, the calculation formula is:

[0062] T r，av = (T r，in + T r，o ) / 2

[0063] Wherein, T r，in and T r，out are the inflow temperature and outflow temperature of the heat fluid, respectively.

[0064] Due to the adoption of the above technical scheme, the following beneficial effects are achieved:

[0065] The present application has the advantages of simple operation, real-time monitoring, reduction of detection work personnel, and improvement of detection efficiency. The present application is a non-destructive testing system, which does not cause secondary damage to the transmission pipeline and does not cause leakage of the constant top circulating gas, thereby increasing the monitoring safety. The present application can effectively monitor the crystallization deposition in the process industrial pipeline equipment in real time, quickly identify the equipment operation risk, and provide effective guidance for process protection. The present application can realize direct monitoring of the pipeline equipment from industrial field data to crystallization deposition, effectively improve the pipeline equipment failure detection efficiency, and reduce the pipeline equipment maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0066] The present application will be further described below in conjunction with specific embodiments:

[0067] Figure 1 It is a schematic diagram of the installation structure of the crystallization monitoring system of the present application.

[0068] Figure 2 It is a distribution diagram of the thermocouple on the interpolation tube.

[0069] Wherein the reference signs are: the inner tube 1, the thermocouple 2, the pipeline 3, the flange 4, the rubber sealing ring 5, the circulating pipeline 6, the constant temperature water tank 7, the pump 8, the flow meter 9, the first temperature detector 10, the second temperature detector 11, the signal transmission line 12, the controller 13, the first thermocouple 21, the second thermocouple 22, the third thermocouple 23, the fourth thermocouple 24, the fifth thermocouple 25, the sixth thermocouple 26. DETAILED DESCRIPTION

[0070] The embodiments of the present application are described below in detail, examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the present application, and cannot be understood as a limitation of the present application.

[0071] In the description of the present application, it is understood that the terms "longitudinal", "transverse", "vertical", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0072] In the description of the present application, unless otherwise specified and limited, it is necessary to explain that the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be mechanical connection or electrical connection, it can be the communication between two elements, it can be direct connection, or indirect connection through intermediate medium, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0073] The embodiments of the present application are described below in detail, examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the present application, and cannot be understood as a limitation of the present application. Figure 1 With Figure 2 The present application is further described as follows:

[0074] As Figure 1 With Figure 2 An industrial crystal deposition online monitoring device is shown, which comprises a real-time monitoring system, an external circulating system and a data processing system. The real-time monitoring system is used for detecting relevant data, which comprises an inner tube 1, a thermocouple 2 and a temperature detector. The external circulating system is used for circulating cold fluid to the inner tube 1, which comprises a circulating pipeline 6, a pump 8, a mass flow meter 9 and a constant temperature water tank 7 connected to the circulating pipeline 6. The data processing system is used for collecting and processing relevant data, which comprises a controller 13 and a signal transmission line 12.

[0075] The inner tube 1 is inserted into the pipeline 3 through the outer wall of the pipeline 3. Specifically, a through hole is formed on the outer wall of the pipeline 3, the inner tube 1 is inserted through the through hole, and a flange 4 is installed at the through hole to fix the inner tube 1. Rubber sealing rings 5 are arranged between the two flanges 4 to achieve complete sealing. Figure 2 As shown in FIG. 2, the bottom of the inner tube 1, i.e., the part inserted into the pipeline 3, is uniformly arranged with thermocouples 2, including a No. 1 thermocouple 21, a No. 2 thermocouple 22, a No. 3 thermocouple 23, a No. 4 thermocouple 24, a No. 5 thermocouple 25, and a No. 6 thermocouple 26. The six thermocouples 2 are combined in pairs, the No. 1 thermocouple 21 is combined with the No. 4 thermocouple 24, the No. 2 thermocouple 22 is combined with the No. 5 thermocouple 25, and the No. 3 thermocouple 23 is combined with the No. 6 thermocouple 26, to measure the data of three radial directions of the inner tube 1, respectively. Among them, the No. 1 thermocouple 21, the No. 2 thermocouple 22, and the No. 3 thermocouple 23 are arranged on the heat receiving surface of the inner tube 1, and the No. 4 thermocouple 24, the No. 5 thermocouple 25, and the No. 6 thermocouple 26 are arranged on the heat back surface of the inner tube 1, so as to detect the outer wall surface temperature of the inner tube 1 at the inflow end and the outer wall surface temperature of the inner tube 1 at the outflow end of the hot fluid, respectively. Each thermocouple 2 is connected to the controller 13 through a signal transmission line 12 out of the inner tube 1.

[0076] The circulating pipeline 6 is connected to the inner tube 1 at both ends, one end of which is inserted into the head of the inner tube 1 and extends to the bottom of the inner tube 1, and the cold fluid in the circulating pipeline 6 enters the inner tube 1 from this end; the other end is connected to the side of the inner tube 1 (not extended into the pipeline 3), so as to achieve the purpose of circulation; the constant temperature water tank 7 and the pump 8 are used to circulate the cold fluid in the inner tube 1 and the circulating pipeline 6, and the constant temperature water tank 7 can control the temperature of the cold fluid to be constant. The flow meter 9 is used to detect the mass flow of the cold fluid, which is connected to the controller 13 through the signal transmission line 12.

[0077] The temperature detection meter includes a first temperature detection meter 10, a second temperature detection meter 11, a third temperature detection meter (not marked in the figure), and a fourth temperature meter (not marked in the figure). The first temperature detection meter 10 is arranged at the inflow end of the circulating pipeline 6 to detect the inflow temperature of the cold fluid; the second temperature detection meter 11 is arranged at the outflow end of the circulating pipeline 6 to detect the outflow temperature of the cold fluid; the third temperature detection meter is arranged at the hot fluid inflow end of the pipeline 3 (i.e., the left end in FIG. 1), to detect the inflow temperature of the hot fluid in the pipeline 3; and the fourth temperature detection meter is arranged at the hot fluid outflow end of the pipeline 3 (i.e., the right end in FIG. 1), to detect the outflow temperature of the hot fluid in the pipeline 3. The first temperature detection meter 10, the second temperature detection meter 11, the third temperature detection meter, and the fourth temperature meter are connected to the controller 13 through the signal transmission line 12 to transmit the collected temperature data to the controller 13. Figure 1 Figure 1

[0078] ​​The data processing system connects the thermocouples 2, the temperature detector and the mass flow meter 9, and calculates the crystallization thickness of the outer wall surface of the inner tube 1 according to the outer wall surface temperature of the inner tube 1, the inflow and outflow temperatures of the hot fluid and the inflow and outflow temperatures of the cold fluid. The signal transmission line 12 connects the controller 13 with the thermocouples 2 and the temperature detector; the controller 13 comprises a data acquisition module and a data analysis module, and the controller 13 is connected with a touch screen, and the data output end of the thermocouples 2 is connected with the input end of the data acquisition module. The data analysis module analyzes and calculates the crystallization thickness of the surface of the inner tube 1 according to the outer wall surface temperature of the inner tube 1 and the inflow and outflow temperatures of the cold and hot fluids collected by the data acquisition module, and displays the crystallization thickness on the touch screen.

[0079] The data acquisition module connects the thermocouples 2, the temperature detector and the mass flow meter 9, and collects the outer wall surface temperature of the inner tube 1, the inflow and outflow temperatures of the hot fluid, the inflow and outflow temperatures of the cold fluid and the mass flow of the cold fluid, and the data analysis module calculates the crystallization thickness of the surface of the inner tube 1 according to the collected outer wall surface temperature of the inner tube 1, the inflow and outflow temperatures of the hot fluid and the inflow and outflow temperatures of the cold fluid.

[0080] A crystallization fouling thickness calculation method, characterized by comprising the following steps:

[0081] S1: The data processing system collects the following data and constructs a database:

[0082] The pipeline thermocouples distributed in the external circulation system collect the real-time inflow temperature T l，in and the real-time outflow temperature T l，out of the cold fluid;

[0083] The pipeline thermocouples distributed at the front end and the rear end of the pipeline collect the real-time inflow temperature T r，in and the real-time outflow temperature T r，out of the hot fluid;

[0084] The six thermocouples distributed in the inner tube measure the real-time temperatures T' out 1 -T' out 6 of the outer wall surface in the non-fouling state after removing the fouling;

[0085] The six thermocouples distributed in the inner tube measure the real-time temperatures T out1 -T out 6 of the outer wall surface in the fouling state;

[0086] The mass flow meter distributed in the external circulation system collects the real-time mass flow q m of the inflow cold fluid; l

[0087] Further comprising the inner radius r1 and the outer radius r2 of the inner tube, and the outer radius r3 of the inner tube in the fouling state, the insertion length l and the wall thickness δ w ​and thermal conductivity λ w , the thermal conductivity of the crystal λ f , the specific heat of the cold fluid C p，l ;

[0088] The mass flow meters distributed in the external circulation system collect the real-time mass flow rate q of the cold fluid flowing in. m，1 .

[0089] S2: Calculate the real-time temperature T′ of the inner wall surface at 6 measuring points of the inner tube in the non-scaling state in 1 ~T′ in 6 ; Calculate the real-time temperature T of the inner wall of the inner tube at 6 measuring points under scaling condition in 1 ~T in 6 . And record it in the database. The calculation formula is as follows:

[0090]

[0091] Among them, k represents 6 measurement points, k∈[1,6];

[0092] T′ out k The real-time temperature of the outer wall of the inner tube at 6 measuring points in the non-scaling state is obtained from S1;

[0093] T out k is the real-time temperature of the outer wall of the inner tube at six measuring points under the scaling state obtained from S1;

[0094] δ w is the wall thickness of the inner tube; w is the thermal conductivity of the inner tube;

[0095] q′ w is the average heat flux density passing through the inner tube wall in the non-scaling state;

[0096] q w is the average heat flux density passing through the inner tube wall under fouling conditions.

[0097] The average heat flux density q of the cold fluid passing through the inner tube wall can be calculated by the following formula:

[0098]

[0099] Among them, the heat transfer through the inner tube wall Q w Equal to the heat exchange of cold fluid Q l , A l Is the heat transfer area of ​​the cold fluid. The heat transfer capacity of the cold fluid Q l Heat exchange area with cold fluid A l The calculation formulas are:

[0100] Q l =Cl q m,1 (T l，out -T l，in )

[0101] A l =d in πl

[0102] where C l and q m , 1 is the specific heat and mass flow of the cold fluid;

[0103] T l，out and T l，in are the outflow temperature and inflow temperature of the cold fluid, respectively.

[0104] d in is the inner wall diameter of the inner tube, and l is the length of the inner tube inserted into the pipeline.

[0105] S3: Calculate the local heat transfer coefficients h'1-h'6 of the 6 measuring points of the inner tube in the clean state. The calculation formula is:

[0106]

[0107] where k represents the 6 measuring points, k∈[1, 6];

[0108] T r，in is the inflow temperature of the hot fluid;

[0109] T'k out is the outer wall temperature of the 6 measuring points of the inner tube in the clean state;

[0110] q' w is the heat flux density in the clean state.

[0111] S4: Calculate the local heat transfer coefficients h1-h6 of the 6 measuring points of the inner tube in the fouling state. The calculation formula is:

[0112]

[0113] where k represents the 6 measuring points, k∈[1, 6];

[0114] T r，in is the inflow temperature of the hot fluid;

[0115] q w is the average heat flux density in the fouling state;

[0116] T out k is the outer wall temperature of the 6 measuring points of the inner tube in the fouling state.

[0117] S5: Calculate the fouling thermal resistance Rf，1 R f,6 The fouling thicknesses δ1-δ6 of the outer wall surface of the six measuring points of the inner tube are calculated, and the calculation formula is as follows:

[0118]

[0119] δ k = r3-r2

[0120] wherein k represents the six measuring points, and k∈[1, 6];

[0121] C l and q m,l are the specific heat and mass flow of the cold fluid;

[0122] l is the length of the inner tube inserted into the pipeline;

[0123] r1, r2 and r3 are the inner radius, outer radius and radius including the fouling thickness of the inner tube, respectively;

[0124] h′ k is the local heat transfer coefficient of the six measuring points of the inner tube in the non-fouling state;

[0125] h k is the local heat transfer coefficient of the six measuring points of the inner tube in the fouling state;

[0126] λ f is the fouling thermal conductivity.

[0127] S6: The fouling thickness difference of the three radial directions of the inner tube is calculated respectively, and the calculation formula is as follows: the fouling thicknesses δ1-δ6 of the outer wall surface of the six measuring points of the inner tube obtained in step S5 are calculated according to the following formula: t1 δ1-δ6 t6

[0128] δ = δ k - δ k+3

[0129] The thicknesses of the three radial directions of the inner tube are obtained, wherein k∈[1, 3].

[0130] The heat receiving surface and the heat back surface of the inner tube are arranged with three thermocouples from top to bottom, respectively, six thermocouples are combined two by two, the first thermocouple is combined with the fourth thermocouple, the second thermocouple is combined with the fifth thermocouple, and the third thermocouple is combined with the sixth thermocouple, to measure the data of the three radial directions of the inner tube, respectively; wherein the first, second and third are arranged on the heat receiving surface of the inner tube, and the fourth, fifth and sixth are arranged on the heat back surface of the inner tube.

[0131] The inflow temperature of the hot fluid in the steps S3 and S4 can be replaced by the average temperature T r，av of the hot fluid, and the calculation formula is as follows:​

[0132] T r，av = (T r，in + T r，o ) / 2

[0133] Wherein, T r，in and T r，out are the inflow temperature and outflow temperature of the hot fluid respectively.

[0134] In the embodiment, the surface temperatures of the six measuring points of the front and back heat flow surfaces of the inner tube 1 are measured by the multiple thermocouples 2 respectively, the detection temperatures of the multiple detection points of the inner tube 1 are acquired by the data acquisition module, the inner and outer wall surface temperatures of the six measuring points are obtained by the data analysis module, and the local heat transfer coefficients of the inner tube 1 under the fouling state and the local heat transfer coefficients of the inner tube 1 under the non-fouling state and the fouling thickness of the surface of the inner tube 1 are calculated by the formula, and the crystallization thickness difference is obtained by subtracting the fouling thickness of the front and back heat flow surfaces.

[0135] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited to this. Any simple change, equivalent replacement or modification made on the basis of the present application to solve the basically same technical problem and realize the basically same technical effect is covered in the protection scope of the present application.

Claims

1. An industrial crystallization deposition on-line monitoring device characterized by: The device comprises a real-time monitoring system, an external circulation system and a data processing system, the real-time monitoring system comprises an inner tube, a thermocouple and a temperature detector, the inner tube is inserted into the pipeline, the thermocouple is arranged on the outer wall of the inner tube and is used for detecting the temperature of the outer wall of the inner tube, the temperature detector is used for detecting the inflow and outflow temperatures of the cold fluid in the inner tube and the inflow and outflow temperatures of the hot fluid in the pipeline, the external circulation system is used for providing circulating constant-temperature cold fluid to the inner tube, and the data processing system is connected with the thermocouple and the temperature detector and is used for calculating the crystallization thickness of the surface of the inner tube according to the temperature of the outer wall of the inner tube and the inflow and outflow temperatures of the hot fluid and the cold fluid.

2. An apparatus for on-line monitoring of crystalline deposition in industrial processes according to claim 1, characterized in that: The six thermocouples of the inner tube are arranged on the hot flow surface and the back hot flow surface of the inner tube from top to bottom.

3. The apparatus for on-line monitoring of crystalline deposit in industrial crystallization according to claim 1, wherein: The external circulation system comprises a circulating pipeline, a pump, a mass flow meter and a constant-temperature water tank connected with the circulating pipeline, the inflow end and the outflow end of the circulating pipeline are connected with the inner tube and are used for circulating constant-temperature cold fluid to the inner tube, the temperature detector comprises a first temperature detector and a second temperature detector, the first temperature detector is arranged on the inflow end of the circulating pipeline and is used for detecting the inflow temperature of the cold fluid, the second temperature detector is arranged on the outflow end of the circulating pipeline and is used for detecting the outflow temperature of the cold fluid, the temperature detector further comprises a third temperature detector and a fourth temperature detector, the third temperature detector is used for detecting the inflow temperature of the hot fluid in the pipeline, and the fourth temperature detector is used for detecting the outflow temperature of the hot fluid in the pipeline, and the mass flow meter is arranged on the inflow end of the circulating pipeline and is used for detecting the real-time mass flow of the cold fluid.

4. An apparatus for on-line monitoring of crystalline deposits in industrial processes according to claim 3, characterized in that: The data processing system comprises a signal transmission line and a controller, the signal transmission line connects the controller with the thermocouple, the temperature detector and the mass flow meter, the controller comprises a data acquisition module and a data analysis module, the data acquisition module is connected with the thermocouple, the temperature detector and the mass flow meter, acquires the temperature of the outer wall of the inner tube, the inflow and outflow temperatures of the hot fluid and the cold fluid and the real-time mass flow of the cold fluid, and the data analysis module calculates the crystallization thickness of the outer wall of the inner tube according to the acquired temperature of the outer wall of the inner tube, the inflow and outflow temperatures of the hot fluid and the cold fluid and the mass flow of the cold fluid.

5. The method for calculating the thickness of crystal fouling in an industrial crystal deposition online monitoring device according to claim 1, characterized in that The method comprises the following steps: S1: the data processing system acquires the following data and constructs a database: A temperature detector distributed in the pipeline of the external circulation system collects the real-time inflow temperature T of the cold fluid l,in and the real-time outflow temperature T l,out ; Temperature detectors distributed at the front and back ends of the pipeline collect the real-time inflow temperature T of the hot fluid r,in and the real-time outflow temperature T r,out ; The 6 thermocouples distributed in the inner tube measure the real-time temperature T' of the outer wall surface in the non-fouling state after removing the fouling out1 ~ T' out6 ; The real-time temperatures of the outer wall of the inner tube measured by the six thermocouples under the fouling state T out1 ~T out6 ; The mass flow meter distributed in the external circulation system collects the real-time mass flow q of the cold fluid inflow m,l : also includes the inner radius r1 and the outer radius r2 of the inner cannula, and the outer radius r3 when scaling, the insertion length l, the wall thickness δ w and the thermal conductivity λ w , the thermal conductivity λ f of the crystal, the specific heat C p,l of the cold fluid; S2: Calculate the real-time temperature T' of the inner wall surface of the 6 measuring points of the inner tube in the non-fouling state in1 ~ T' in6 ; Calculate the real-time temperature T of the inner wall surface of the 6 measuring points of the inner tube in the fouling state in1 ~ T in6 ; and record in the database; the calculation formula is as follows: Wherein, k represents the six measuring points, and k ∈ [1, 6]; T′ outk is the real-time temperature of the outer wall surface of the six measuring points of the inner probe in the non-fouling state obtained in S1; T outk is the real-time temperature of the outer wall surface of the six measuring points of the inner probe in the fouling state obtained in S1; δ w is the inner cannula wall thickness; λ w is the thermal conductivity of the inner cannula; q' w q' is the average heat flux density across the wall of the cannula in the clean condition; q w q is the average heat flux through the wall of the cannula in the fouled state; S3: calculating the local heat transfer coefficients h'1-h'6 of the six measuring points of the inner tube under the non-fouling state; S4: calculating the local heat transfer coefficients h1-h6 of the six measuring points of the inner tube under the fouling state; S5: Calculate the fouling thermal resistance R of the six measuring points f,1 ~R f,6 ; Calculate the fouling thickness δ1-δ6 of the outer wall surface of the six measuring points of the inner tube; the calculation formula is as follows: delta k = r3 - r2 Wherein, k represents the six measuring points, and k ∈ [1, 6]; C l and q m,l is the specific heat and mass flow of the cold fluid; l is the length of the inner tube inserted into the pipeline; r1, r2 and r3 are respectively the inner radius, the outer radius and the radius containing the fouling thickness of the inner tube. h′ k h is the local heat transfer coefficient for the 6 points of the tube in the clean state; h k Local heat transfer coefficients were measured for 6 points on the tube for the fouled condition. λ f For fouling thermal conductivity; S6: Calculate the difference in the crystal thickness in the three radial directions of the inner tube, and the calculation formula is as follows: the dirt thickness δ of the outer wall surface of the six measuring points obtained from step S5 t1 ~ δ t6 , calculated according to the following formula: δ = δ k - δ k+3 The thickness of the three radial direction crystallization of the inner tube is obtained, wherein k∈[1, 3].

6. The method of claim 5, wherein: The heat flow surface and the back heat flow surface of the inner tube are arranged with three thermocouples from top to bottom, respectively, six thermocouples are combined in pairs, the first thermocouple is combined with the fourth thermocouple, the second thermocouple is combined with the fifth thermocouple, and the third thermocouple is combined with the sixth thermocouple, respectively, to measure the data of the three radial directions of the inner tube; wherein the first, second and third are arranged on the heat flow surface of the inner tube, and the fourth, fifth and sixth are arranged on the back heat flow surface of the inner tube.

7. The method of claim 5, wherein: The average heat flux density q of the cold fluid passing through the wall surface of the inner tube is calculated by the following formula: Q w is the heat exchange amount of the cold fluid l , A l is the heat exchange area of the cold fluid; the calculation formulas of the heat exchange amount Q l of the cold fluid and the heat exchange area A l of the cold fluid are as follows: Q l = C l q m,l (T l,out -T l,in ) A l = d in πl where C l and q m,l is the specific heat and mass flow of the cold fluid; T l,out and T l,in are the outflow and inflow temperatures of the cold fluid, respectively; d in D is the inner wall diameter of the inner tube, and l is the length of the inner tube inserted into the pipe.

8. The method of claim 5, wherein: The local heat transfer coefficients h'1-h'6 of the six measuring points of the inner tube under the scale-free state are calculated by the following formula: Wherein k represents the six measuring points, k∈[1, 6]; T r,in temperature of the inflow of the thermal fluid; T' outk To measure the temperature of the outer wall surface of the 6 points of the endoscope in the state of no fouling; q' w q is the heat flux in the fouled state.

9. The method of claim 8, wherein: The local heat transfer coefficients h1-h6 of the six measuring points of the inner tube under the scale-free state are calculated by the following formula: Wherein k represents the six measuring points, k∈[1, 6]; The local heat transfer coefficients h1-h6 of the six measuring points of the inner tube under the scale-free state are calculated by the following formula: Wherein k represents the six measuring points, k∈[1, 6]; T r,in temperature of the inflow of the thermal fluid; q w is the average heat flux in the fouled state; T outk The outer wall surface temperature of the 6 measuring points of the internal tube in the fouling state was measured.

10. The method of claim 9, wherein: The inflow temperature of the hot fluid of the steps S3, S4 can be the average temperature T r,av Instead, the calculation formula is: where T r,in and T r,out are the inlet and outlet temperatures of the hot fluid, respectively.

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