Online cleaning and descaling system and method for heat supply heat exchanger

Abstract

The invention provides a heat supply heat exchanger online cleaning and descaling system and method, and relates to the technical field of heat supply heat exchangers, the heat supply heat exchanger online cleaning and descaling system comprises a cleaning prompt module, an online cleaning and descaling module and an outer wall cleaning module, the cleaning prompt module is electrically connected with the online cleaning and descaling module and the outer wall cleaning module, and the online cleaning and descaling module is electrically connected with the outer wall cleaning module. The cleaning prompting module is used for conducting cleaning prompting based on the using state of the heat exchanger, the online cleaning and descaling module is used for conducting online cleaning and descaling on the inner wall of the heat exchanger, and the outer wall cleaning module is used for cleaning the outer wall of the heat exchanger. Online cleaning of the heat exchanger is achieved, cleaning of the inner wall and the outer wall can be conducted without shutdown, the operation efficiency of equipment is remarkably improved, the service life of the equipment is prolonged, and the requirement for manual intervention is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of heating heat exchangers, and in particular relates to an online cleaning and descaling system and method for a heating heat exchanger. Background Art

[0002] The heat exchangers used for heating in thermal power plants are generally tubular heat exchangers and plate heat exchangers. Since the circulating water used is of poor quality and contains a large number of scaling ions, scale is easily generated on the inner wall of the tube bundle or between the plates after a period of operation, causing the efficiency of the heat exchanger to decrease. Generally, thermal power plants clean and descale the heat exchangers after the heating period ends. Since the system cannot be shut down independently during the heating period, the heat exchange effect of the heat exchanger is poor and the energy loss is large. Summary of the invention

[0003] The present invention provides an online cleaning and descaling system and method for a heat exchanger, which are used to solve at least one of the technical problems mentioned above.

[0004] In order to solve the above technical problems, the present invention discloses an online cleaning and descaling system and method for a heating heat exchanger, comprising a cleaning reminder module, an online cleaning and descaling module and an outer wall cleaning module, the cleaning reminder module being electrically connected to the online cleaning and descaling module and the outer wall cleaning module, the cleaning reminder module being used to provide cleaning reminders based on the usage status of the heat exchanger, the online cleaning and descaling module being used to perform online cleaning and descaling of the inner wall of the heat exchanger, and the outer wall cleaning module being used to perform outer wall cleaning of the heat exchanger.

[0005] Preferably, the online cleaning and descaling module comprises a water tank, a self-circulating water pump, a gas mixing device and a plurality of heat exchangers, the self-circulating water pump and the gas mixing device are connected in parallel to form a mixing circuit, the water tank is connected to the inlet end of the mixing circuit through a delivery branch 1, and the outlet end of the mixing circuit is connected to a delivery branch 2, a delivery branch 3 is provided on the water tank, a plurality of heat exchange branches are provided between the delivery branches 2 and 3, a plurality of heat exchangers are respectively provided on the heat exchange branches, and a control valve 1 and a control valve 2 are respectively provided at the inlet end and the outlet end of the heat exchanger on the heat exchange branch; The water tank is provided with an acid addition port and a slag discharge port.

[0006] Preferably, the cleaning prompt module includes: A data acquisition unit, used to collect the mass flow of the heat exchanger, the pressure of the medium at the inlet and outlet of the heat exchanger, the temperature of the medium at the inlet and outlet of the heat exchanger, and the flow rate of the medium at the inlet and outlet of the heat exchanger; A heat exchange capacity evaluation value determination unit, used to calculate the heat exchange capacity evaluation value of the heat exchanger in each detection cycle based on the collection result of the data collection unit; The cleaning analysis unit is used to analyze whether the heat exchanger needs to be cleaned based on the heat exchange capacity evaluation value of the heat exchanger in each detection cycle, and determine whether to clean the outer wall or the inner wall.

[0007] Preferably, the cleaning analysis unit comprises: A cleaning prediction matrix construction subunit is used to construct a cleaning prediction matrix for the heat exchanger based on the heat exchange capacity evaluation value of the heat exchanger in each detection cycle; The first analysis subunit is used to predict the heat exchange capacity evaluation value of the heat exchanger in the next detection cycle based on the cleaning prediction matrix of the heat exchanger, and compare the prediction result with the basic evaluation value of the heat exchange capacity of the heat exchanger; If the heat exchange capacity evaluation value of the heat exchanger in the next detection cycle is less than the heat exchange capacity basic evaluation value of the heat exchanger, it is determined that the current heat exchanger needs to be cleaned, and the analysis subunit 1 sends a further analysis prompt to the analysis subunit 2; Otherwise, it proves that the current heat exchanger does not need to be cleaned; Analysis subunit two is used to calculate the actual flow resistance capacity of the tube wall dirt in the current detection cycle of the heat exchanger. If the actual flow resistance capacity of the tube wall dirt in the current detection cycle of the heat exchanger is greater than the preset flow resistance capacity of the tube wall dirt of the heat exchanger, an inner wall cleaning and descaling prompt is sent to the online cleaning and descaling module; otherwise, an outer wall cleaning prompt is sent to the outer wall cleaning module.

[0008] Preferably, the heat exchange capacity evaluation value of the heat exchanger in each detection cycle is calculated based on the collection results of the data collection unit: ;in, is the heat transfer capacity evaluation value of the heat exchanger in the i-th detection cycle, lg is the logarithm with base 10, is the pressure at the inlet of the heat exchanger in the i-th detection cycle, is the pressure at the outlet of the heat exchanger in the i-th detection cycle, is the reference pressure difference across the heat exchanger, is the mass flow rate of the medium in the heat exchanger during the i-th detection cycle, is the specific heat capacity of the medium in the heat exchanger, is the temperature of the medium at the inlet of the heat exchanger in the i-th detection cycle, is the base heat transfer coefficient of the heat exchanger, is the surface area of ​​the heat exchanger, It is the preset reference temperature after the medium in the heat exchanger is cooled down. is the logarithm to base e, is the temperature of the medium at the outlet of the heat exchanger in the i-th detection cycle.

[0009] Preferably, based on the heat exchange capacity evaluation value of the heat exchanger in each detection cycle, a cleaning prediction matrix of the heat exchanger is constructed: The heat transfer capacity evaluation value of the heat exchanger in each test cycle Sort by time series, obtain the first row of the cleaning prediction matrix, use the difference between the right value of each element in the first row of the cleaning prediction matrix and the element as the second row element corresponding to the element, wherein the second row element corresponding to the last element in the first row is set to the same value as the second row element corresponding to the first element in the first row, and all the second row elements constitute the second row of the cleaning prediction matrix, use the difference between the left value of each element in the first row of the cleaning prediction matrix and the element as the third row element corresponding to the element, wherein the third row element corresponding to the first element in the first row is set to the same value as the third row element corresponding to the last element in the first row, and all the third row elements constitute the third row of the cleaning prediction matrix; ;in, is the cleaning prediction matrix of the heat exchanger in the i-th detection cycle, is the heat transfer capacity evaluation value of the heat exchanger in the first detection cycle, is the heat transfer capacity evaluation value of the heat exchanger in the second test cycle, is the heat exchange capacity evaluation value of the heat exchanger in the third test cycle, is the heat transfer capacity evaluation value of the heat exchanger in the i-1th detection cycle, is the heat transfer capacity evaluation value of the heat exchanger in the i-th detection cycle; Predict the heat exchange capacity evaluation value of the heat exchanger in the next inspection cycle based on the cleaning prediction matrix of the heat exchanger: Obtain the mean of all matrix elements in the third row of the cleaning prediction matrix of the heat exchanger in the i-th detection cycle, and modify the value of the last column of the cleaning prediction matrix of the heat exchanger in the i-th detection cycle to the same value as the mean of all matrix elements in the third row to obtain a new matrix, and take the product of the rank of the new matrix and the heat exchange capacity evaluation value of the heat exchanger in the i-th detection cycle as the heat exchange capacity evaluation value of the heat exchanger in the i+1-th detection cycle.

[0010] Preferably, the actual flow resistance of the tube wall fouling of the heat exchanger in the current detection cycle is: ;in, is the actual flow resistance capacity of the tube wall fouling of the heat exchanger in the i-th detection cycle, represents the logarithm with base e, is the flow rate of the medium at the inlet of the heat exchanger in the i-th detection cycle, is the flow rate of the medium at the outlet of the heat exchanger in the i-th detection cycle, is the difference in the reference flow rate at both ends of the heat exchanger, is the Reynolds number.

[0011] A method for online cleaning and descaling of a heat exchanger, comprising the following steps: Step 1: The cleaning prompt module determines the heat exchange capacity evaluation value of the heat exchanger based on the collected data of the heat exchanger; Step 2: Determine whether the heat exchanger needs to be cleaned based on the heat exchange capacity evaluation value analysis, and determine whether to clean the outer wall or the inner wall; Step 3: If it is determined that the inner wall is to be cleaned, the online cleaning and descaling module responds; if it is determined that the outer wall is to be cleaned, the outer wall cleaning module responds; When the online cleaning and descaling module is working, the control valve 1 and the control valve 2 of the heat exchange branch corresponding to the heat exchanger to be cleaned are opened, and then the acid is added to the water tank through the acid addition port. Then the water containing the acid flows into the mixing circuit through the transmission branch 1, and the water vapor is mixed and expanded through the self-circulating water pump and the gas mixing device to form high-pressure water vapor. The high-pressure water vapor enters the corresponding heat exchanger through the heat exchange branch to violently flush the inner wall of the heat exchanger. At the same time, an appropriate amount of acid decomposes the scale layer on the inner wall of the heat exchanger. Finally, the decomposed product and the cleaning wastewater are discharged into the water tank through the transmission branch 3, and finally discharged from the slag discharge port; The outer wall cleaning module is an intelligent cleaning robot.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention combines a cleaning reminder module, an online cleaning and descaling module and an outer wall cleaning module to work together. The cleaning reminder module provides a cleaning reminder according to the use status of the heat exchanger, determines whether cleaning is required and whether the cleaning part is the inner wall or the outer wall. The online cleaning and descaling module uses acid and high-pressure water vapor to strongly clean the inner wall of the heat exchanger to remove dirt and decompose the scale layer. The waste liquid after cleaning is discharged through the slag discharge port. The outer wall cleaning module uses an intelligent cleaning robot to complete the cleaning task of the outer wall of the heat exchanger. The present invention realizes online cleaning of the heat exchanger, and the inner wall and the outer wall can be cleaned without stopping the machine, which significantly improves the operation efficiency of the equipment, prolongs the service life of the equipment, and reduces the need for manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is an overall schematic diagram of the online cleaning and descaling system for a heat supply heat exchanger of the present invention.

[0014] In the figure: 1. Water tank; 2. Self-circulating water pump; 3. Gas mixing device; 4. Heat exchanger; 5. Delivery branch 1; 6. Delivery branch 2; 7. Delivery branch 3; 8. Heat exchange branch; 9. Control valve 1; 10. Control valve 2; 11. Acid addition port; 12. Slag discharge port. DETAILED DESCRIPTION

[0015] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0016] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0017] The present invention provides the following embodiments Example 1 The embodiment of the present invention provides a system and method for online cleaning and descaling of a heat exchanger. Figure 1 As shown, the system includes a cleaning reminder module, an online cleaning and descaling module and an outer wall cleaning module. The cleaning reminder module is electrically connected to the online cleaning and descaling module and the outer wall cleaning module. The cleaning reminder module is used to provide cleaning reminders based on the usage status of the heat exchanger 4. The online cleaning and descaling module is used to perform online cleaning and descaling of the inner wall of the heat exchanger 4. The outer wall cleaning module is used to clean the outer wall of the heat exchanger 4.

[0018] A method for online cleaning and descaling of a heat exchanger, comprising the following steps: Step 1: The cleaning prompt module determines the heat exchange capacity evaluation value of the heat exchanger 4 based on the collected data of the heat exchanger 4; Step 2: Determine whether the heat exchanger 4 needs to be cleaned based on the heat exchange capacity evaluation value analysis, and determine whether to clean the outer wall or the inner wall; Step 3: If it is determined that the inner wall is to be cleaned, the online cleaning and descaling module responds; if it is determined that the outer wall is to be cleaned, the outer wall cleaning module responds; When the online cleaning and descaling module is working, the control valve 1 9 and the control valve 2 10 of the heat exchange branch 8 corresponding to the heat exchanger 4 to be cleaned are opened, and then the acid is added to the water tank 1 through the acid addition port 11, and then the water containing the acid flows into the mixing circuit through the delivery branch 1 5, and the water vapor is mixed and expanded through the self-circulating water pump 2 and the gas mixing device 3 to form high-pressure water vapor, which enters the corresponding heat exchanger 4 through the heat exchange branch 8 to violently flush the inner wall of the heat exchanger 4, and at the same time, a proper amount of acid decomposes the scale layer on the inner wall of the heat exchanger 4, and finally the decomposed product and the cleaning waste water are discharged into the water tank 1 through the delivery branch 3 7, and finally discharged from the slag discharge port 12; The outer wall cleaning module is an intelligent cleaning robot.

[0019] The working principle and beneficial effects of the above technical solution are as follows: the present invention combines the cleaning prompt module, the online cleaning and descaling module and the outer wall cleaning module to work together. The cleaning prompt module provides a cleaning prompt according to the use status of the heat exchanger 4, determines whether cleaning is required and whether the cleaning part is the inner wall or the outer wall. The online cleaning and descaling module uses acid and high-pressure water vapor to strongly clean the inner wall of the heat exchanger 4 to remove dirt and decompose the scale layer. The waste liquid after cleaning is discharged through the slag discharge port 12. The outer wall cleaning module uses an intelligent cleaning robot to complete the cleaning task of the outer wall of the heat exchanger 4. The present invention realizes online cleaning of the heat exchanger 4, and the inner wall and the outer wall can be cleaned without stopping the machine, which significantly improves the operation efficiency of the equipment, prolongs the service life of the equipment, and reduces the need for manual intervention.

[0020] Example 2 On the basis of Example 1, the online cleaning and descaling module includes a water tank 1, a self-circulating water pump 2, a gas mixing device 3 and a plurality of heat exchangers 4. The self-circulating water pump 2 and the gas mixing device 3 are connected in parallel to form a mixing circuit. The water tank 1 is connected to the inlet end of the mixing circuit through a delivery branch 1 5, and the outlet end of the mixing circuit is connected to a delivery branch 2 6. A delivery branch 3 7 is provided on the water tank 1, and a plurality of heat exchange branches 8 are provided between the delivery branch 2 6 and the delivery branch 3 7. The plurality of heat exchangers 4 are respectively arranged on the heat exchange branches 8, and the inlet end and the outlet end of the heat exchanger 4 on the heat exchange branch 8 are respectively provided with a control valve 1 9 and a control valve 2 10; The water tank 1 is provided with an acid liquid adding port 11 and a slag discharging port 12 .

[0021] The working principle and beneficial effects of the above technical solution are as follows: the self-circulating water pump 2 and the gas mixing device 3 of the present invention are connected in parallel to form a mixing circuit, acid liquid is provided through the water tank 1, and the mixing circuit realizes water vapor mixing and expansion to form high-pressure water vapor. The high-pressure water vapor enters the inner wall of the heat exchanger 4 through the heat exchange branch 8, strongly flushes the inner wall and decomposes the scale layer, and the waste liquid after cleaning returns to the water tank 1 through the conveying branch three 7. The high-pressure water vapor formed by the water vapor mixing can effectively remove the dirt on the inner wall of the heat exchanger 4, thereby improving the cleaning efficiency.

[0022] Example 3 Based on Example 1, the cleaning prompt module includes: A data acquisition unit, used to acquire the mass flow of the heat exchanger 4, the pressure of the medium at the inlet and outlet of the heat exchanger 4, the temperature of the medium at the inlet and outlet of the heat exchanger 4, and the flow rate of the medium at the inlet and outlet of the heat exchanger 4; A heat exchange capacity evaluation value determination unit, used to calculate the heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle based on the collection result of the data collection unit; The cleaning analysis unit is used to analyze whether the heat exchanger 4 needs to be cleaned based on the heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle, and determine whether to clean the outer wall or the inner wall.

[0023] The working principle and beneficial effects of the above technical solution are as follows: the cleaning prompt module of the present invention monitors the mass flow, pressure, temperature, flow rate and other parameters of the heat exchanger 4 in real time through the data acquisition unit, and calculates the heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle in combination with the heat exchange capacity evaluation value determination unit. The cleaning analysis unit determines whether cleaning is needed according to the heat exchange capacity evaluation value and determines the cleaning location. By real-time monitoring of the working status of the heat exchanger 4, it is possible to promptly discover the decrease in heat exchange capacity and perform cleaning in advance to avoid the reduction in efficiency due to dirt accumulation. In addition, the cleaning location is accurately determined, which improves the pertinence and efficiency of cleaning.

[0024] Example 4 On the basis of Example 3, the cleaning analysis unit comprises: A cleaning prediction matrix construction subunit is used to construct a cleaning prediction matrix of the heat exchanger 4 based on the heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle; The first analysis subunit is used to predict the heat exchange capacity evaluation value of the heat exchanger 4 in the next detection cycle based on the cleaning prediction matrix of the heat exchanger 4, and compare the prediction result with the heat exchange capacity basic evaluation value of the heat exchanger 4; If the heat exchange capacity evaluation value of the heat exchanger 4 in the next detection cycle is less than the heat exchange capacity basic evaluation value of the heat exchanger 4, it is determined that the current heat exchanger 4 needs to be cleaned, and the analysis subunit 1 sends a further analysis prompt to the analysis subunit 2; Otherwise, it is proved that the current heat exchanger 4 does not need to be cleaned; The second analysis subunit is used to calculate the actual flow resistance capacity of the tube wall dirt in the current detection cycle of the heat exchanger 4. If the actual flow resistance capacity of the tube wall dirt in the current detection cycle of the heat exchanger 4 is greater than the preset flow resistance capacity of the tube wall dirt of the heat exchanger 4, an inner wall cleaning and descaling prompt is sent to the online cleaning and descaling module; otherwise, an outer wall cleaning prompt is sent to the outer wall cleaning module.

[0025] The working principle and beneficial effects of the above technical solution: the cleaning analysis unit establishes a cleaning prediction matrix through a cleaning prediction matrix construction sub-unit, predicts the heat exchange capacity evaluation value of the heat exchanger 4 in the next detection cycle, and compares it with the basic evaluation value. If the predicted value is lower than the basic evaluation value, it is determined that cleaning is required. The analysis sub-unit 2 further calculates the actual flow resistance capacity of the tube wall dirt of the heat exchanger 4 and determines the cleaning location. The cleaning prediction matrix can predict the performance change of the heat exchanger 4 in advance to achieve preventive maintenance. The flow resistance capacity calculation of the analysis sub-unit 2 ensures the accuracy of the cleaning decision, reduces unnecessary cleaning operations, and reduces maintenance costs.

[0026] Example 5 On the basis of Example 3, the heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle is calculated based on the collection results of the data collection unit: ;in, is the heat exchange capacity evaluation value of the heat exchanger 4 in the i-th detection cycle, lg is the logarithm with base 10, is the pressure at the inlet of heat exchanger 4 in the i-th detection cycle, is the pressure at the outlet of heat exchanger 4 in the i-th detection cycle, is the reference pressure difference across the heat exchanger 4, is the mass flow rate of the medium in the heat exchanger 4 during the i-th detection cycle, is the specific heat capacity of the medium in heat exchanger 4, is the temperature of the medium at the inlet of heat exchanger 4 in the i-th detection cycle, is the reference heat transfer coefficient of heat exchanger 4, is the surface area of ​​the heat exchanger 4, is the preset reference temperature after the medium in the heat exchanger 4 is cooled down, is the logarithm to base e, is the temperature of the medium at the outlet of the heat exchanger 4 in the i-th detection cycle.

[0027] The working principle and beneficial effects of the above technical solution are as follows: the calculation formula for the heat exchange capacity evaluation value comprehensively considers factors such as the pressure, temperature, mass flow rate, etc. at the inlet and outlet ends of the heat exchanger 4. Through the changes in these parameters, the heat exchange capacity of the heat exchanger 4 can be quantified and it can be determined whether it needs to be cleaned. The above formula provides a scientific evaluation method that can accurately reflect the changes in the heat exchange capacity of the heat exchanger 4. This quantitative evaluation method provides a reliable basis for cleaning decisions and helps to optimize the operating efficiency of the heat exchanger 4.

[0028] Example 6 On the basis of Example 4, based on the heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle, a cleaning prediction matrix of the heat exchanger 4 is constructed: The heat exchange capacity evaluation value of the heat exchanger 4 in each detection cycle Sort by time series, obtain the first row of the cleaning prediction matrix, use the difference between the right value of each element in the first row of the cleaning prediction matrix and the element as the second row element corresponding to the element, wherein the second row element corresponding to the last element in the first row is set to the same value as the second row element corresponding to the first element in the first row, and all the second row elements constitute the second row of the cleaning prediction matrix, use the difference between the left value of each element in the first row of the cleaning prediction matrix and the element as the third row element corresponding to the element, wherein the third row element corresponding to the first element in the first row is set to the same value as the third row element corresponding to the last element in the first row, and all the third row elements constitute the third row of the cleaning prediction matrix; ;in, is the cleaning prediction matrix of heat exchanger 4 in the i-th detection cycle, is the heat exchange capacity evaluation value of heat exchanger 4 in the first detection cycle, is the heat exchange capacity evaluation value of heat exchanger 4 in the second detection cycle, is the heat exchange capacity evaluation value of heat exchanger 4 in the third detection cycle, is the heat exchange capacity evaluation value of the heat exchanger 4 in the i-1th detection cycle, is the heat exchange capacity evaluation value of the heat exchanger 4 in the i-th detection cycle; The heat exchange capacity evaluation value of the heat exchanger 4 in the next detection cycle is predicted based on the cleaning prediction matrix of the heat exchanger 4: Obtain the mean of all matrix elements in the third row of the cleaning prediction matrix of the heat exchanger 4 in the i-th detection cycle, and modify the value of the last column in the cleaning prediction matrix of the heat exchanger 4 in the i-th detection cycle to the same value as the mean of all matrix elements in the third row to obtain a new matrix, and take the product of the rank of the new matrix and the heat exchange capacity evaluation value of the heat exchanger 4 in the i-th detection cycle as the heat exchange capacity evaluation value of the heat exchanger 4 in the i+1-th detection cycle.

[0029] The working principle and beneficial effects of the above technical solution are as follows: the cleaning prediction matrix is ​​constructed through time series sorting and difference calculation, and the product of the matrix rank and the heat exchange capacity evaluation value is used to predict the heat exchange capacity evaluation value of the next detection cycle. This method combines historical data and current status to improve the accuracy of the prediction. The cleaning prediction matrix can effectively capture the changing trend of the performance of the heat exchanger 4 and achieve more accurate cleaning time prediction. By predicting the cleaning needs in advance, the efficiency loss caused by delayed cleaning can be avoided, while reducing unnecessary cleaning operations.

[0030] Example 7 Based on Example 4, the actual flow resistance capacity of the tube wall fouling of the heat exchanger 4 in the current detection cycle is: 3; among them, is the actual flow resistance of the tube wall fouling of the heat exchanger 4 in the i-th detection cycle, represents the logarithm with base e, is the flow rate of the medium at the inlet of heat exchanger 4 in the i-th detection cycle, is the flow rate of the medium at the outlet of heat exchanger 4 in the i-th detection cycle, is the difference in the reference flow rate at both ends of the heat exchanger 4, is the Reynolds number.

[0031] The working principle and beneficial effects of the above technical solution are as follows: the actual flow resistance capacity of the tube wall fouling is calculated through parameters such as the Reynolds number and the velocity difference, which is used to determine the degree of fouling of the heat exchanger 4 in the current detection cycle. If the actual flow resistance capacity exceeds the preset value, it is determined that the current heat exchange capacity is mainly due to the influence of the inner wall fouling, and the inner wall needs to be cleaned. By calculating the flow resistance capacity, the degree of fouling of the inner wall of the heat exchanger 4 can be accurately evaluated, thereby reasonably arranging a cleaning plan.

[0032] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An online cleaning and descaling system for a heating heat exchanger, characterized in that: The heat exchanger (4) comprises a cleaning prompt module, an online cleaning and descaling module and an outer wall cleaning module. The cleaning prompt module is electrically connected to the online cleaning and descaling module and the outer wall cleaning module. The cleaning prompt module is used to provide cleaning prompts based on the use status of the heat exchanger (4). The online cleaning and descaling module is used to perform online cleaning and descaling of the inner wall of the heat exchanger (4). The outer wall cleaning module is used to perform outer wall cleaning of the heat exchanger (4).

2. The online cleaning and descaling system for a heat exchanger according to claim 1, characterized in that: The online cleaning and descaling module comprises a water tank (1), a self-circulating water pump (2), a gas mixing device (3) and a plurality of heat exchangers (4); the self-circulating water pump (2) and the gas mixing device (3) are connected in parallel to form a mixing circuit; the water tank (1) is connected to the inlet end of the mixing circuit via a first delivery branch (5); the outlet end of the mixing circuit is connected to a second delivery branch (6); a third delivery branch (7) is provided on the water tank (1); a plurality of heat exchange branches (8) are provided between the second delivery branch (6) and the third delivery branch (7); a plurality of heat exchangers (4) are respectively arranged on the heat exchange branches (8); and a first control valve (9) and a second control valve (10) are respectively provided at the inlet end and the outlet end of the heat exchanger (4) on the heat exchange branch (8); The water tank (1) is provided with an acid liquid addition port (11) and a slag discharge port (12).

3. The online cleaning and descaling system for a heat exchanger according to claim 1, characterized in that: The cleaning prompt module comprises: A data acquisition unit, used to collect the mass flow of the heat exchanger (4), the pressure of the medium at the inlet and outlet of the heat exchanger (4), the temperature of the medium at the inlet and outlet of the heat exchanger (4), and the flow rate of the medium at the inlet and outlet of the heat exchanger (4); A heat exchange capacity evaluation value determination unit, used to calculate a heat exchange capacity evaluation value of the heat exchanger (4) in each detection cycle based on the collection result of the data collection unit; The cleaning analysis unit is used to analyze whether the heat exchanger (4) needs to be cleaned based on the heat exchange capacity evaluation value of the heat exchanger (4) in each detection cycle, and to determine whether to clean the outer wall or the inner wall.

4. The online cleaning and descaling system for a heat exchanger according to claim 3 is characterized in that: The cleaning analysis unit comprises: A cleaning prediction matrix construction subunit is used to construct a cleaning prediction matrix of the heat exchanger (4) based on the heat exchange capacity evaluation value of the heat exchanger (4) in each detection cycle; An analysis subunit 1 is used to predict a heat exchange capacity evaluation value of the heat exchanger (4) in the next detection cycle based on a cleaning prediction matrix of the heat exchanger (4), and compare the prediction result with a basic evaluation value of the heat exchange capacity of the heat exchanger (4); If the heat exchange capacity evaluation value of the heat exchanger (4) in the next detection cycle is less than the heat exchange capacity basic evaluation value of the heat exchanger (4), it is determined that the current heat exchanger (4) needs to be cleaned, and at this time, the analysis subunit 1 sends a further analysis prompt to the analysis subunit 2; Otherwise, it is proved that the current heat exchanger (4) does not need to be cleaned; The second analysis subunit is used to calculate the actual flow resistance capacity of the tube wall dirt of the heat exchanger (4) in the current detection cycle. If the actual flow resistance capacity of the tube wall dirt of the heat exchanger (4) in the current detection cycle is greater than the preset flow resistance capacity of the tube wall dirt of the heat exchanger (4), an inner wall cleaning and descaling prompt is sent to the online cleaning and descaling module; otherwise, an outer wall cleaning prompt is sent to the outer wall cleaning module.

5. The online cleaning and descaling system for a heat exchanger according to claim 3, characterized in that: The heat exchange capacity evaluation value of the heat exchanger (4) in each detection cycle is calculated based on the collection results of the data collection unit: ;in, is the heat transfer capacity evaluation value of the heat exchanger (4) in the i-th detection cycle, lg is the logarithm with base 10, is the pressure at the inlet of the heat exchanger (4) during the i-th detection cycle, is the pressure at the outlet of the heat exchanger (4) during the i-th detection cycle, is the reference pressure difference across the heat exchanger (4), is the mass flow rate of the medium in the heat exchanger (4) during the i-th detection cycle, is the specific heat capacity of the medium in the heat exchanger (4), is the temperature of the medium at the inlet of the heat exchanger (4) in the i-th detection cycle, is the base heat transfer coefficient of the heat exchanger (4), is the surface area of ​​the heat exchanger (4), is the preset reference temperature of the medium in the heat exchanger (4) after the temperature is reduced. is the logarithm to base e, is the temperature of the medium at the outlet of the heat exchanger (4) in the i-th detection cycle.

6. The online cleaning and descaling system for a heat exchanger according to claim 4, characterized in that: Based on the heat exchange capacity evaluation value of the heat exchanger (4) in each detection cycle, a cleaning prediction matrix of the heat exchanger (4) is constructed: The heat transfer capacity evaluation value of the heat exchanger (4) in each detection cycle is Sort by time series, obtain the first row of the cleaning prediction matrix, use the difference between the right value of each element in the first row of the cleaning prediction matrix and the element as the second row element corresponding to the element, wherein the second row element corresponding to the last element in the first row is set to the same value as the second row element corresponding to the first element in the first row, and all the second row elements constitute the second row of the cleaning prediction matrix, use the difference between the left value of each element in the first row of the cleaning prediction matrix and the element as the third row element corresponding to the element, wherein the third row element corresponding to the first element in the first row is set to the same value as the third row element corresponding to the last element in the first row, and all the third row elements constitute the third row of the cleaning prediction matrix; ;in, is the cleaning prediction matrix of the heat exchanger (4) in the i-th detection cycle, is the heat transfer capacity evaluation value of the heat exchanger (4) in the first detection cycle, is the heat transfer capacity evaluation value of the heat exchanger (4) in the second detection cycle, is the heat transfer capacity evaluation value of the heat exchanger (4) in the third test cycle, is the heat transfer capacity evaluation value of the heat exchanger (4) in the i-1th detection cycle, is the heat exchange capacity evaluation value of the heat exchanger (4) in the i-th detection cycle; Based on the cleaning prediction matrix of the heat exchanger (4), the heat exchange capacity evaluation value of the heat exchanger (4) in the next detection cycle is predicted: The mean value of all matrix elements in the third row of the cleaning prediction matrix of the heat exchanger (4) in the i-th detection cycle is obtained, and the value of the last column of the cleaning prediction matrix of the heat exchanger (4) in the i-th detection cycle is modified to a value that is the same as the mean value of all matrix elements in the third row, to obtain a new matrix, and the product of the rank of the new matrix and the heat exchange capacity evaluation value of the heat exchanger (4) in the i-th detection cycle is used as the heat exchange capacity evaluation value of the heat exchanger (4) in the i+1-th detection cycle.

7. The online cleaning and descaling system for a heat exchanger according to claim 4, characterized in that: Actual flow resistance of the tube wall fouling of the heat exchanger (4) during the current test cycle: ;in, is the actual flow resistance of the tube wall fouling of the heat exchanger (4) in the i-th detection cycle, represents the logarithm with base e, is the flow rate of the medium at the inlet of the heat exchanger (4) in the i-th detection cycle, is the flow rate of the medium at the outlet of the heat exchanger (4) in the i-th detection cycle, is the difference in the reference flow rate at both ends of the heat exchanger (4), is the Reynolds number.

8. A method for online cleaning and descaling of a heating heat exchanger, for performing online cleaning and descaling of a heating heat exchanger using an online cleaning and descaling system for a heating heat exchanger as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: The cleaning prompt module determines the heat exchange capacity evaluation value of the heat exchanger (4) based on the collected data of the heat exchanger (4); Step 2: determining whether the heat exchanger (4) needs to be cleaned based on the heat exchange capacity evaluation value analysis, and determining whether to clean the outer wall or the inner wall; Step 3: If it is determined that the inner wall is to be cleaned, the online cleaning and descaling module responds; if it is determined that the outer wall is to be cleaned, the outer wall cleaning module responds; When the online cleaning and descaling module is working, the control valve 1 (9) and the control valve 2 (10) of the heat exchange branch (8) corresponding to the heat exchanger (4) to be cleaned are opened, and then the acid is added to the water tank (1) through the acid addition port (11). Then, the water containing the acid flows into the mixing circuit through the delivery branch 1 (5), and the water vapor is mixed and expanded by the self-circulating water pump (2) and the gas mixing device (3) to form high-pressure water vapor. The high-pressure water vapor enters the corresponding heat exchanger (4) through the heat exchange branch (8) and violently flushes the inner wall of the heat exchanger (4). At the same time, an appropriate amount of acid decomposes the scale layer on the inner wall of the heat exchanger (4). Finally, the decomposed product and the cleaning waste water are discharged into the water tank (1) through the delivery branch 3 (7), and finally discharged from the slag discharge port (12); The outer wall cleaning module is an intelligent cleaning robot.

Images