Cleaning system of plate heat exchanger

Abstract

The invention provides a cleaning system for a plate heat exchanger, and relates to the technical field of heat exchanger cleaning, the cleaning system comprises a heat exchanger body, a treated water inlet pipe, a treated water outlet pipe, a cooling water inlet pipe and a cooling water outlet pipe are connected to the heat exchanger body, and the cooling water inlet pipe communicates with a first cleaning pipe; the other end of the first cleaning pipe is communicated with the liquid storage tank, cleaning liquid is stored in the liquid storage tank, the cooling water outlet pipe is communicated with a second cleaning pipe, the other end of the second cleaning pipe is communicated with the waste liquid tank, the cooling water inlet pipe and the cooling water outlet pipe are provided with a first control valve and a second control valve respectively, and the first cleaning pipe is provided with a third control valve and a first circulating pump. And a control valve IV is mounted on the cleaning pipe II. The cleaning pipeline is connected, cleaning is carried out in the mode of generating chemical products, and online cleaning of the plate heat exchanger is achieved. Compared with manual cleaning, the maintenance time is greatly shortened, the labor intensity is reduced, convenience and rapidness are achieved, and the heat exchange efficiency of the plate heat exchanger is improved.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchanger cleaning, and in particular to a cleaning system for a plate heat exchanger. Background Art

[0002] During the use of plate heat exchangers, affected by water quality and temperature, calcium and magnesium carbonates in the water decompose to form precipitates when heated. The precipitates and other impurities accumulate at the inlet and outlet of the exchanger and the heating surface, increasing the pressure drop of the equipment, reducing the heat exchange efficiency of the heat exchanger, and impacting and wearing the plates. Traditional manual disassembly and cleaning cycles are long, and the internal sealing strips and plates are easily damaged, with high labor and maintenance costs. Summary of the invention

[0003] The present invention provides a cleaning system for a plate heat exchanger, which is used to solve the defects in the prior art of long cleaning cycle of traditional manual plate disassembly, easy damage to internal sealing strips and plates, and high labor and maintenance costs.

[0004] On the one hand, the present invention provides a cleaning system for a plate heat exchanger, including a heat exchanger body, the heat exchanger body being connected with a treated water inlet pipe, a treated water outlet pipe, a cooling water inlet pipe and a cooling water outlet pipe, the cooling water inlet pipe being connected with a cleaning pipe 1, the other end of the cleaning pipe 1 being connected with a liquid storage tank, the liquid storage tank storing cleaning liquid, the cooling water outlet pipe being connected with a cleaning pipe 2, the other end of the cleaning pipe 2 being connected with a waste liquid tank, the cooling water inlet pipe and the cooling water outlet pipe being respectively installed with a control valve 1 and a control valve 2, the cleaning pipe 1 being installed with a control valve 3 and a circulating pump 1, and the cleaning pipe 2 being installed with a control valve 4.

[0005] Preferably, it also includes a waste liquid treatment component, the liquid inlet of the waste liquid treatment component is connected with the waste liquid tank through an infusion tube 1, a circulating pump 2 is installed on the infusion tube 1, the liquid outlet of the waste liquid treatment tank is connected with a cleaning tube 1 through an infusion tube 2, a circulating pump 3 and a control valve 5 are installed on the infusion tube 2, and the waste liquid treatment component is used to purify the waste liquid in the waste liquid tank to obtain a recovered solution.

[0006] Preferably, a second control system is also included, and the control system includes:

[0007] A temperature monitoring module is used to obtain the real-time fluid temperature of the treated water inlet pipe and the treated water outlet pipe;

[0008] A cleaning judgment module is used to calculate the fluid temperature difference, and when the fluid temperature difference is less than a preset temperature difference threshold requiring cleaning, the cleaning process is executed;

[0009] T z =T r -T c ; Among them, T z is the fluid temperature difference; Tr is the fluid temperature of the process water inlet pipe; T c The fluid temperature of the treated water outlet pipe;

[0010] A cleaning control module, used to control the cleaning process;

[0011] The valve control module is used to control the opening and closing of control valve one, control valve two, control valve three, control valve four and control valve five.

[0012] Preferably, the waste liquid treatment component includes a treatment box, which is internally provided with a sedimentation chamber, a storage chamber and a waste collection chamber, the sedimentation chamber and the storage chamber are arranged above the waste collection chamber, the sedimentation chamber and the storage chamber are connected through a liquid extraction tube, a liquid extraction pump is arranged on the liquid extraction tube, the liquid outlet of infusion tube one is connected with the sedimentation chamber, the liquid inlet of infusion tube two extends into the bottom of the storage chamber, a filter is installed at the liquid inlet of infusion tube two, a liquid outlet one is arranged below the sedimentation chamber and is connected with the waste collection chamber, an electrically controlled gate valve one is installed at the liquid outlet one, a liquid outlet two is arranged at the bottom of the storage chamber and is connected with the waste collection chamber, and an electrically controlled gate valve two is installed at the liquid outlet two.

[0013] Preferably, the waste liquid treatment component further comprises a first control system, and the first control system comprises:

[0014] A pH detector is disposed in the storage chamber and is used to detect the pH value of the recovered solution in the storage chamber;

[0015] Three groups of liquid level sensors are respectively arranged in the sedimentation chamber, the storage chamber and the waste collection chamber, and are used to detect the liquid level heights in the sedimentation chamber, the storage chamber and the waste collection chamber;

[0016] The gate control module is used to control the opening and closing of the electric-controlled gate valve 1 and the electric-controlled gate valve 2;

[0017] The liquid level alarm module generates a liquid level alarm when the liquid level detected by any group of liquid level sensors in the sedimentation chamber, storage chamber and waste collection chamber is higher than the corresponding warning liquid level.

[0018] Preferably, the gate control module includes:

[0019] A sedimentation control unit is used to start timing after the sedimentation chamber is filled with liquid, start the liquid pump to start the liquid pumping process after the timing reaches a specified time, and open the electric control gate valve 1 after the liquid pumping process is completed;

[0020] The judgment control unit is used to judge whether the detection result of the pH meter is within the preset allowable range of the pH value. If the detection result of the pH meter is within the preset allowable range of the pH value, the electric-controlled gate valve 2 will not be opened. If the detection result of the pH meter is not within the preset allowable range of the pH value, the electric-controlled gate valve 2 will be opened.

[0021] Preferably, the cleaning process includes preliminary cleaning and deep cleaning, and the cleaning control module includes:

[0022] A preliminary cleaning unit, used for passing the recovered solution purified by the waste liquid treatment component into the plate heat exchanger as preliminary cleaning;

[0023] A deep cleaning unit, used to pass the cleaning liquid stored in the liquid storage tank into the plate heat exchanger for deep cleaning;

[0024] A water flushing unit, used for flushing with water based on the consumption of the recovery solution or the cleaning solution during the preliminary cleaning and deep cleaning;

[0025] The judgment switching unit is used to judge whether the preliminary cleaning process is completed each time the water flushing is performed during the preliminary cleaning process, and switch to deep cleaning when it is judged that the preliminary cleaning process is completed.

[0026] Preferably, the judgment switching unit includes:

[0027] A flow sensor is provided on the treated water outlet pipe to obtain the actual flow of the treated water;

[0028] A data recording subunit, used to record the historical flow rate of treated water and the historical inlet and outlet water temperatures;

[0029] A comparison establishment subunit is used to establish a comparison data group, which includes the historical flow rate and historical inlet and outlet water temperatures of the treated water at the comparison time point;

[0030] A judgment subunit, used for calculating a switching judgment parameter, and when the switching judgment parameter is less than a preset switching threshold, it is judged that the preliminary cleaning process is completed, otherwise it is judged that the preliminary cleaning process is not completed;

[0031]

[0032] P is the switching judgment parameter; V d is the actual flow rate of treated water at the comparison time point; t 0 is the unit time; T dr is the inlet temperature of the treated water at the comparison time point; T dc V is the outlet temperature of the treated water at the comparison time point; x is the actual flow rate of the current treated water; T xr is the current inlet temperature of the treated water; T xc is the current outlet temperature of the treated water; V q is the actual flow rate of treated water before cleaning; T qr is the inlet temperature of the treated water before cleaning; T qc is the outlet temperature of the treated water before cleaning; Δt (dx)The length of time from the comparison time point to the current time point; T 0 is the preset temperature difference threshold for cleaning; μ T0 T 0 The expected value of the heat exchange efficiency improvement of the corresponding preliminary cleaning; U is the total volume of the recovered solution actually used after being purified by the waste liquid treatment component; U 0 It is the prescribed value of the volume of the recovery solution used for one water flush during the initial cleaning process;

[0033] The switching subunit is used to switch to deep cleaning after judging that the preliminary cleaning process is completed.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] By connecting a cleaning pipeline to the cooling water circulation pipeline, injecting cleaning liquid into the cooling water circulation pipeline for flushing, cleaning by generating chemical products, and removing some impurities through large-flow flushing, the plate heat exchanger can be cleaned online without disassembling the plate. Compared with manual cleaning, it greatly shortens the maintenance time and reduces labor intensity. At the same time, it does not occupy the production site, is convenient and fast, and improves the heat exchange efficiency of the plate heat exchanger. It avoids damage to the internal sealing strips and plates caused by manual disassembly and cleaning, saving equipment maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the structure of the present invention;

[0038] Figure 2 It is a schematic structural diagram of the waste liquid treatment component of the present invention.

[0039] Reference numerals:

[0040] 1. Heat exchanger body; 2. Treatment water inlet pipe; 3. Treatment water outlet pipe; 4. Cooling water inlet pipe; 5. Cooling water outlet pipe; 6. Cleaning pipe 1; 7. Liquid storage tank; 8. Cleaning pipe 2; 9. Waste liquid tank; 10. Control valve 1; 11. Control valve 2; 12. Control valve 3; 13. Circulation pump 1; 14. Control valve 4; 15. Infusion pipe 1; 16. Circulation pump 2; 17. Infusion pipe 2; 18. Circulation pump 3; 19. Control valve 5; 20. Treatment tank; 21. Sedimentation chamber; 22. Storage chamber; 23. Waste collection chamber; 24. Extraction pipe; 25. Liquid outlet 1; 26. Electric gate valve 1; 27. Liquid outlet 2; 28. Electric gate valve 2; 29. ​​Waste liquid treatment component. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] 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.

[0043] Example 1

[0044] An embodiment of the present invention provides a cleaning system for a plate heat exchanger, including a heat exchanger body 1, to which a treated water inlet pipe 2, a treated water outlet pipe 3, a cooling water inlet pipe 4 and a cooling water outlet pipe 5 are connected, the cooling water inlet pipe 4 is connected with a cleaning pipe 6, the other end of the cleaning pipe 6 is connected with a liquid storage tank 7, and the liquid storage tank 7 stores cleaning liquid, the cooling water outlet pipe 5 is connected with a cleaning pipe 2 8, the other end of the cleaning pipe 2 8 is connected with a waste liquid tank 9, the cooling water inlet pipe 4 and the cooling water outlet pipe 5 are respectively installed with a control valve 10 and a control valve 2 11, the cleaning pipe 1 6 is installed with a control valve 3 12 and a circulating pump 13, and the cleaning pipe 2 8 is installed with a control valve 4 14.

[0045] Preferably, it also includes a waste liquid treatment component 29, the liquid inlet of the waste liquid treatment component 29 is connected to the waste liquid tank 9 through an infusion tube 15, and a circulating pump 2 16 is installed on the infusion tube 15. The liquid outlet of the waste liquid treatment tank 20 is connected to the cleaning tube 6 through an infusion tube 2 17, and a circulating pump 3 18 and a control valve 5 19 are installed on the infusion tube 2 17. The waste liquid treatment component 29 is used to purify the waste liquid in the waste liquid tank 9 to obtain a recovered solution.

[0046] Preferably, a second control system is also included, and the control system includes:

[0047] A temperature monitoring module is used to obtain the real-time fluid temperature of the treated water inlet pipe 2 and the treated water outlet pipe 3;

[0048] A cleaning judgment module is used to calculate the fluid temperature difference, and when the fluid temperature difference is less than a preset temperature difference threshold requiring cleaning, the cleaning process is executed;

[0049] T z =T r -T c ; Among them, T z is the fluid temperature difference; T r is the fluid temperature of the process water inlet pipe; T c The fluid temperature of the treated water outlet pipe;

[0050] A cleaning control module, used to control the cleaning process;

[0051] The valve control module is used to control the opening and closing of control valve 1 10 , control valve 2 11 , control valve 3 12 , control valve 4 14 and control valve 5 19 .

[0052] In this embodiment, the cleaning liquid is oxalic acid solution.

[0053] The beneficial effects of the above technical solution are:

[0054] When the plate heat exchanger works normally, control valve one 10 and control valve two 11 are opened, control valve three 12, control valve four 14, and control valve five 19 are closed. At this time, the fluid flowing in the cooling water inlet pipe 4 and the cooling water outlet pipe 5 is cooling water, thereby realizing heat exchange between cooling water and treated water.

[0055] When cleaning the plate heat exchanger, first open control valve four 14 and control valve five 19, close control valve one 10, control valve two 11 and control valve three 12, first inject purified waste liquid into the plate heat exchanger to perform preliminary cleaning of the plate heat exchanger, thereby improving the utilization rate of the cleaning liquid and reducing the cleaning cost of the plate heat exchanger.

[0056] After preliminary cleaning, open control valve three 12 and control valve four 14, and close control valve one 10, control valve two 11 and control valve five 19, so as to inject pure cleaning liquid into the plate heat exchanger, and further deeply clean the interior of the plate heat exchanger to ensure the cleaning effect. After the pure cleaning liquid flows through the plate heat exchanger, it flows into the waste liquid tank 9 through the cleaning pipe two 8 for storage, and then is recycled after purification through the waste liquid treatment component 29, thereby reducing the loss of cleaning liquid.

[0057] By monitoring the fluid temperature of the treated water inlet pipe 2 and the treated water outlet pipe 3, it is automatically determined whether to clean according to the fluid temperature difference, thereby realizing the automation of the cleaning process and ensuring the timeliness of cleaning, thereby ensuring the stability of the heat exchange efficiency of the plate heat exchanger. There is no need for manual monitoring by staff, which reduces the workload of staff.

[0058] By providing the waste liquid treatment component 29, the waste liquid generated after cleaning is purified, thereby realizing the reuse of the cleaning liquid, improving the utilization rate of the cleaning liquid, reducing the consumption of the cleaning liquid, and reducing the cleaning cost of the plate heat exchanger.

[0059] By connecting a cleaning pipeline to the cooling water circulation pipeline, injecting cleaning liquid into the cooling water circulation pipeline for flushing, cleaning by generating chemical products, and removing some impurities through large-flow flushing, the plate heat exchanger can be cleaned online without disassembling the plate. Compared with manual cleaning, it greatly shortens the maintenance time and reduces labor intensity. At the same time, it does not occupy the production site, is convenient and fast, and improves the heat exchange efficiency of the plate heat exchanger. It avoids damage to the internal sealing strips and plates caused by manual disassembly and cleaning, saving equipment maintenance costs.

[0060] Example 2

[0061] On the basis of Example 1, the waste liquid treatment component 29 includes a treatment box 20, and the treatment box 20 is provided with a sedimentation chamber 21, a storage chamber 22 and a waste collection chamber 23. The sedimentation chamber 21 and the storage chamber 22 are arranged above the waste collection chamber 23, and the sedimentation chamber 21 and the storage chamber 22 are connected through a liquid suction tube 24, and a liquid suction pump is arranged on the liquid suction tube 24. The liquid outlet of the infusion tube 15 is connected to the sedimentation chamber 21, and the liquid inlet of the infusion tube 21 extends into the bottom of the storage chamber 22. The liquid inlet of the infusion tube 21 is installed with a filter net. A liquid outlet 25 is arranged below the sedimentation chamber 21 to be connected to the waste collection chamber 23, and the liquid outlet 25 is installed with an electrically controlled gate valve 26. A liquid outlet 27 is arranged at the bottom of the storage chamber 22 to be connected to the waste collection chamber 23, and the liquid outlet 27 is installed with an electrically controlled gate valve 28.

[0062] Preferably, the waste liquid treatment component 29 further includes a first control system, which includes:

[0063] A pH detector, disposed in the storage chamber 22, for detecting the pH value of the recovery solution in the storage chamber 22;

[0064] Three groups of liquid level sensors are respectively arranged in the sedimentation chamber 21, the storage chamber 22 and the waste collection chamber 23, and are used to detect the liquid level heights in the sedimentation chamber 21, the storage chamber 22 and the waste collection chamber 23;

[0065] The gate control module is used to control the opening and closing of the electric-controlled gate valve 1 26 and the electric-controlled gate valve 2 28;

[0066] The liquid level alarm module generates a liquid level alarm when the liquid level detected by any group of liquid level sensors in the sedimentation chamber 21, the storage chamber 22 and the waste collection chamber 23 is higher than the corresponding warning liquid level.

[0067] Preferably, the gate control module includes:

[0068] A sedimentation control unit, which is used to start timing after the sedimentation chamber 21 is filled with liquid, and start the liquid pump to start the liquid extraction process after the timing reaches a specified time, and open the electric control gate valve 26 after the liquid extraction process is completed;

[0069] The judgment control unit is used to judge whether the detection result of the pH meter is within the preset allowable range of the pH value. If the detection result of the pH meter is within the preset allowable range of the pH value, the electric control gate valve 28 will not be opened. If the detection result of the pH meter is not within the preset allowable range of the pH value, the electric control gate valve 28 will be opened.

[0070] The beneficial effects of the above technical solution are:

[0071] When purifying the waste liquid, firstly, the waste liquid is pumped into the sedimentation chamber 21 through the infusion tube 15. After settling for a specified time, the supernatant is pumped into the storage chamber 22 through the pumping tube 24. After the supernatant is extracted, the electric control gate valve 26 is controlled to open, so that the remaining liquid in the sedimentation chamber 21 flows into the waste collection chamber 23, so as to facilitate the purification of the next batch of waste liquid, thus realizing the automation of the waste liquid purification process, without the need for manual intervention, ensuring the efficiency of waste liquid purification, improving the waste liquid purification efficiency, and reducing the workload of the staff.

[0072] The recovered solution drawn into the storage chamber 22 is tested for pH value by a pH meter. If the test result of the pH meter is within the preset allowable range of pH value, it means that the recovered solution in the storage chamber 22 has reuse value, so it is stored and waited for reuse. If the test result of the pH meter is not within the preset allowable range of pH value, it means that the recovered solution in the storage chamber 22 has no reuse value, so the electric-controlled gate valve 28 is opened to allow the recovered solution in the storage chamber 22 to flow into the waste collecting chamber 23.

[0073] By installing a filter at the liquid inlet of the infusion tube 17, the purity of the recovered solution is further guaranteed, and the cleaning effect of the plate heat exchanger is guaranteed. By setting a pH detector to detect the recovered solution in the storage chamber 22, it is ensured that the recovered solution in the storage chamber 22 has reuse value, which further guarantees the cleaning effect of the plate heat exchanger. By setting liquid level sensors in the sedimentation chamber 21, the storage chamber 22 and the waste collection chamber 23, liquid leakage caused by excessive liquid levels in the sedimentation chamber 21, the storage chamber 22 and the waste collection chamber 23 is avoided.

[0074] Example 3

[0075] Based on Example 1 or 2, the cleaning process includes preliminary cleaning and deep cleaning, and the cleaning control module includes:

[0076] A preliminary cleaning unit, used to pass the recovered solution purified by the waste liquid treatment component 29 into the plate heat exchanger as a preliminary cleaning;

[0077] A deep cleaning unit, used to pass the cleaning liquid stored in the liquid storage tank 7 into the plate heat exchanger for deep cleaning;

[0078] A water flushing unit, used for flushing with water based on the consumption of the recovery solution or the cleaning solution during the preliminary cleaning and deep cleaning;

[0079] The judgment switching unit is used to judge whether the preliminary cleaning process is completed each time the water flushing is performed during the preliminary cleaning process, and switch to deep cleaning when it is judged that the preliminary cleaning process is completed.

[0080] Preferably, the judgment switching unit includes:

[0081] A flow sensor is provided on the treated water outlet pipe 3 to obtain the actual flow of the treated water;

[0082] A data recording subunit, used to record the historical flow rate of treated water and the historical inlet and outlet water temperatures;

[0083] A comparison establishment subunit is used to establish a comparison data group, which includes the historical flow rate and historical inlet and outlet water temperatures of the treated water at the comparison time point;

[0084] A judgment subunit, used for calculating a switching judgment parameter, and when the switching judgment parameter is less than a preset switching threshold, it is judged that the preliminary cleaning process is completed, otherwise it is judged that the preliminary cleaning process is not completed;

[0085] Among them, P is the switching judgment parameter; V d is the actual flow rate of treated water at the comparison time point; t 0 is the unit time; T dris the inlet temperature of the treated water at the comparison time point; T dc V is the outlet temperature of the treated water at the comparison time point; x is the actual flow rate of the current treated water; T xr is the current inlet temperature of the treated water; T xc is the current outlet temperature of the treated water; V q is the actual flow rate of treated water before cleaning; T qr is the inlet temperature of the treated water before cleaning; T qc is the outlet temperature of the treated water before cleaning; Δt (dx) The length of time from the comparison time point to the current time point; T 0 A preset temperature difference threshold value for cleaning; T 0 The expected value of the heat exchange efficiency improvement of the corresponding preliminary cleaning; U is the total volume of the recovered solution actually used after being purified by the waste liquid treatment component; U 0 It is the prescribed value of the volume of the recovery solution used for one water flush during the initial cleaning process;

[0086] The switching subunit is used to switch to deep cleaning after judging that the preliminary cleaning process is completed.

[0087] In this embodiment, the prescribed value of the volume of the recovery solution used for one water flushing is 0 After adding the volume of recovery solution, rinse with water once.

[0088] In this embodiment, the comparison time point is the time point when the water flushing was last performed.

[0089] In this embodiment, water flushing is to pass clean water into the plate heat exchanger through the treated water inlet pipe 2 and the cooling water inlet pipe 4 for flushing.

[0090] The beneficial effects of the above technical solution are:

[0091] By flushing with water after using a certain amount of recovery solution or cleaning liquid, the sediment generated by the cleaning process inside the plate heat exchanger can be brought out by clean water, thereby reducing the sediment mixed in the recovery solution or cleaning liquid, thereby improving the reusability of the recovery solution and cleaning liquid. By judging whether the preliminary cleaning process is completed during each water flushing, it is ensured that the preliminary cleaning achieves a certain cleaning effect, thereby ensuring the utilization rate of the recovery solution and reducing the consumption of the cleaning liquid.

[0092] When judging whether the preliminary cleaning is completed, the degree of change in the cleaning effect during the two water flushings (used to judge whether continuing to use the recovery solution can produce further cleaning effects) and the difference between the actual cleaning effect and the expected value of the cleaning effect (used to judge whether the expected cleaning effect is achieved) are considered respectively, and then corrections are made by considering the total number of water flushings during the preliminary cleaning process. This improves the reliability of the switching judgment parameters, and judges whether to continue using the recovery solution for cleaning based on the switching judgment parameters, thereby realizing automatic switching between preliminary cleaning and deep cleaning, improving the high utilization rate of the recovery solution, and avoiding the waste of the recovery solution caused by the useless consumption of the recovery solution.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cleaning system for a plate heat exchanger, characterized in that: The heat exchanger comprises a heat exchanger body (1), the heat exchanger body (1) is connected with a treated water inlet pipe (2), a treated water outlet pipe (3), a cooling water inlet pipe (4) and a cooling water outlet pipe (5), the cooling water inlet pipe (4) is connected with a cleaning pipe 1 (6), the other end of the cleaning pipe 1 (6) is connected with a liquid storage tank (7), the liquid storage tank (7) stores cleaning liquid, the cooling water outlet pipe (5) is connected with a cleaning pipe 2 (8), the other end of the cleaning pipe 2 (8) is connected with a waste liquid tank (9), the cooling water inlet pipe (4) and the cooling water outlet pipe (5) are respectively installed with a control valve 1 (10) and a control valve 2 (11), the cleaning pipe 1 (6) is installed with a control valve 3 (12) and a circulating pump 1 (13), and the cleaning pipe 2 (8) is installed with a control valve 4 (14).

2. A cleaning system for a plate heat exchanger according to claim 1, characterized in that: The invention also comprises a waste liquid treatment component (29), the liquid inlet of the waste liquid treatment component (29) is connected to the waste liquid tank (9) through a liquid infusion pipe (15), a circulating pump (16) is installed on the liquid infusion pipe (15), the liquid outlet of the waste liquid treatment tank (20) is connected to the cleaning pipe (6) through a liquid infusion pipe (17), a circulating pump (18) and a control valve (19) are installed on the liquid infusion pipe (17), and the waste liquid treatment component (29) is used to purify the waste liquid in the waste liquid tank (9) to obtain a recovered solution.

3. A cleaning system for a plate heat exchanger according to claim 2, characterized in that: Also includes a second control system, the control system includes: A temperature monitoring module, used to obtain the real-time fluid temperature of the treated water inlet pipe (2) and the treated water outlet pipe (3); A cleaning judgment module is used to calculate the fluid temperature difference, and when the fluid temperature difference is less than a preset temperature difference threshold value requiring cleaning, the cleaning process is executed; T z =T r -T c ; Among them, T z is the fluid temperature difference; T r is the fluid temperature of the process water inlet pipe; T c The fluid temperature of the treated water outlet pipe; A cleaning control module, used to control the cleaning process; The valve control module is used to control the opening and closing of control valve one (10), control valve two (11), control valve three (12), control valve four (14) and control valve five (19).

4. A cleaning system for a plate heat exchanger according to claim 2, characterized in that: The waste liquid treatment component (29) comprises a treatment box (20), wherein a sedimentation chamber (21), a storage chamber (22) and a waste collection chamber (23) are arranged inside the treatment box (20), wherein the sedimentation chamber (21) and the storage chamber (22) are arranged above the waste collection chamber (23), wherein the sedimentation chamber (21) and the storage chamber (22) are connected via a liquid extraction pipe (24), wherein a liquid extraction pump is arranged on the liquid extraction pipe (24), wherein a liquid outlet of a liquid infusion pipe 1 (15) is connected to the sedimentation chamber (21), The liquid inlet of the second infusion tube (17) extends into the bottom of the storage chamber (22), and a filter screen is installed at the liquid inlet of the second infusion tube (17). A first liquid outlet (25) is provided below the sedimentation chamber (21) and communicates with the waste collection chamber (23), and an electric-controlled gate valve (26) is installed at the first liquid outlet (25). A second liquid outlet (27) is provided at the bottom of the storage chamber (22) and communicates with the waste collection chamber (23), and an electric-controlled gate valve (28) is installed at the second liquid outlet (27).

5. A cleaning system for a plate heat exchanger according to claim 4, characterized in that: The waste liquid treatment component (29) further includes a first control system, the first control system including: A pH detector, disposed in the storage chamber (22), for detecting the pH value of the recovery solution in the storage chamber (22); Three groups of liquid level sensors are respectively arranged in the sedimentation chamber (21), the storage chamber (22) and the waste collection chamber (23) and are used to detect the liquid level heights in the sedimentation chamber (21), the storage chamber (22) and the waste collection chamber (23); A gate control module, used to control the opening and closing of the electric-controlled gate valve 1 (26) and the electric-controlled gate valve 2 (28); The liquid level alarm module generates a liquid level alarm when the liquid level detected by any group of liquid level sensors in the sedimentation chamber (21), the storage chamber (22) and the waste collection chamber (23) is higher than the corresponding warning liquid level.

6. A cleaning system for a plate heat exchanger according to claim 5, characterized in that: The gate control module includes: A sedimentation control unit, used to start timing after the sedimentation chamber (21) is filled with liquid, start the liquid pump to start the liquid extraction process after the timing reaches a specified time, and open the electric control gate valve (26) after the liquid extraction process is completed; The judgment control unit is used to judge whether the detection result of the pH meter is within the preset allowable range of the pH value. If the detection result of the pH meter is within the preset allowable range of the pH value, the second electric-controlled gate valve (28) will not be opened; if the detection result of the pH meter is not within the preset allowable range of the pH value, the second electric-controlled gate valve (28) will be opened.

7. A cleaning system for a plate heat exchanger according to claim 3, characterized in that: The cleaning process includes preliminary cleaning and deep cleaning. The cleaning control module includes: A preliminary cleaning unit, used for passing the recovered solution purified by the waste liquid treatment component (29) into the plate heat exchanger as a preliminary cleaning; A deep cleaning unit, used for passing the cleaning liquid stored in the liquid storage tank (7) into the plate heat exchanger for deep cleaning; A water flushing unit, used for flushing with water based on the consumption of the recovery solution or the cleaning solution during the preliminary cleaning and deep cleaning; The judgment switching unit is used to judge whether the preliminary cleaning process is completed each time the water flushing is performed during the preliminary cleaning process, and switch to deep cleaning when it is judged that the preliminary cleaning process is completed.

8. A cleaning system for a plate heat exchanger according to claim 7, characterized in that: The judgment switching unit comprises: A flow sensor is arranged on the treated water outlet pipe (3) and is used to obtain the actual flow rate of the treated water; A data recording subunit, used to record the historical flow rate of treated water and the historical inlet and outlet water temperatures; A comparison establishment subunit is used to establish a comparison data group, which includes the historical flow rate and historical inlet and outlet water temperatures of the treated water at the comparison time point; A judgment subunit, used for calculating a switching judgment parameter, and when the switching judgment parameter is less than a preset switching threshold, it is judged that the preliminary cleaning process is completed, otherwise it is judged that the preliminary cleaning process is not completed; Among them, P is the switching judgment parameter; V d is the actual flow rate of treated water at the comparison time point; t0 is the unit time; T dr is the inlet temperature of the treated water at the comparison time point; T dc V is the outlet water temperature of the treated water at the comparison time point; x is the actual flow rate of the current treated water; T xr is the current inlet temperature of the treated water; T xc is the current outlet temperature of the treated water; V q is the actual flow rate of treated water before cleaning; T qr T is the inlet temperature of the treated water before cleaning; qc is the outlet temperature of the treated water before cleaning; Δt (dx) is the length of time from the comparison time point to the current time point; T0 is the preset temperature difference threshold value that needs to be cleaned; is the expected value of the heat exchange efficiency improvement of the preliminary cleaning corresponding to T0; U is the total volume of the recovered solution purified by the waste liquid treatment component actually used; U0 is the specified value of the used volume of the recovered solution corresponding to one water flushing during the preliminary cleaning process; The switching subunit is used to switch to deep cleaning after judging that the preliminary cleaning process is completed.

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