Desulfurization slurry waste heat exchanger with online pulse cleaning function

Abstract

The utility model relates to a desulfurization system waste heat utilization technical field, especially disclose a kind of desulfurization slurry waste heat exchanger with online pulse cleaning function.The heat exchanger includes the waste heat exchanger body of tubular shell structure, slurry circulating switching unit, water side pulse cleaning unit, heat load monitoring calorimeter, automatic control unit and electric blowdown valve, slurry circulating switching unit contains parallel connection's slurry main road and slurry bypass, can realize slurry flow through or bypass heat exchanger body;Water side pulse cleaning unit contains flushing electric bypass valve, flushing pulse pressurizing valve and cleaning bypass pipeline, can inject water side high-pressure pulse water into slurry flow side;Automatic control unit is connected with each valve, calorimeter signal, can trigger and control flushing-soaking-discharge cycle cleaning process.The utility model can isolate heat exchanger online under the premise of not affecting desulfurization tower operation and efficiently clean, significantly restore and maintain waste heat recovery efficiency.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization technology in desulfurization systems, and in particular to a waste heat exchanger for desulfurization slurry with online pulse cleaning function. Background Technology

[0002] In wet desulfurization systems in industries such as thermal power generation and chemical processing, the desulfurization slurry discharged from the absorption tower usually carries waste heat of 40°C to 60°C. Direct discharge would result in energy waste. Therefore, it is necessary to recover this heat through a waste heat exchanger for desulfurization slurry and use it for preheating process water, heating, etc., to achieve energy cascade utilization.

[0003] However, desulfurization slurry is a complex multiphase fluid containing a large number of solid particles such as gypsum crystals, unreacted limestone, and fly ash. When it flows through the waste heat exchanger, these particles are prone to deposit and scale on the inner wall of the heat exchange tube, forming a heat insulation layer. This leads to a significant increase in heat transfer resistance and a sharp decrease in heat exchange efficiency. In severe cases, it can even cause blockage of the heat exchange tube, forcing the system to be shut down for cleaning.

[0004] Existing cleaning methods have significant drawbacks: First, manual disassembly and cleaning during system shutdown is time-consuming, labor-intensive, and disrupts production, resulting in substantial economic losses. Second, chemical cleaning may corrode heat exchange tubes (especially stainless steel) and poses a risk of chemical residue contaminating the desulfurization system. Third, existing online cleaning technologies (such as continuous low-pressure water flushing) lack sufficient scouring force and are ineffective at cleaning stubborn, hardened deposits, failing to fully restore heat exchange efficiency. Therefore, there is an urgent need in this field for a device that can automatically and efficiently remove deposits from heat exchange tubes while ensuring continuous waste heat recovery efficiency under the premise of uninterrupted operation of the desulfurization system. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a desulfurization slurry waste heat exchanger with online pulse cleaning function. This solves the technical problem that existing desulfurization slurry waste heat exchangers suffer from reduced heat exchange efficiency due to the deposition of solid particles in the desulfurization slurry on the inner wall of the heat exchange tubes, and that existing methods such as manual disassembly and cleaning during shutdown, chemical cleaning, or continuous low-pressure water online cleaning cannot achieve efficient online cleaning without affecting the operation of the desulfurization tower.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A waste heat exchanger for desulfurized slurry with online pulse cleaning function includes a waste heat exchanger body 1, which is a shell-and-tube structure, with the shell side forming the slurry flow side and the tube side forming the water flow side. The slurry circulation switching unit 2 includes a slurry main line electric valve 21, a slurry bypass inlet valve 22, a slurry bypass outlet valve 23 and supporting pipelines. The slurry main line is connected in parallel with the slurry flow side, and the slurry bypass is connected in series with the slurry bypass inlet valve 22 and the slurry bypass outlet valve 23 and is connected in parallel with the slurry main line. The water-side pulse cleaning unit 3 includes a flushing electric bypass valve 31, a flushing pulse pressurization valve 32, and a cleaning bypass pipeline. The two valves are connected in series in the water flow side bypass. One end of the cleaning bypass pipeline is connected to the pipeline between the two valves, and the other end is connected to the slurry flow side. Heat load monitoring calorimeter 4 is installed on the inlet and outlet pipelines of the water flow side or the slurry flow side; The automatic control unit 5 is connected to the slurry main line electric valve 21, the slurry bypass inlet valve 22, the slurry bypass outlet valve 23, the flushing electric bypass valve 31, the flushing pulse pressurization valve 32, and the heat load monitoring calorimeter 4 via signal lines. The electric drain valve 6 has its inlet end connected to the bottom of the slurry flow side via a drain pipe.

[0007] Preferably, the heat exchange tubes of the waste heat exchanger body 1 are made of duplex stainless steel.

[0008] Preferably, the output pressure adjustment range of the flushing pulse pressurization valve 32 is 0.4MPa to 1.0MPa, and the pulse frequency adjustment range is 1 pulse / minute to 5 pulses / minute.

[0009] Preferably, the heat load monitoring calorimeter 4 is an electromagnetic calorimeter with a measurement accuracy of not less than ±1.5%, and has a built-in data storage module and trend analysis module.

[0010] Preferably, the heat load monitoring calorimeter 4 is an ultrasonic calorimeter with a measurement accuracy of not less than ±1.5% and has the function of bidirectional data interaction with the automatic control unit 5.

[0011] Preferably, the automatic control unit 5 includes a touch screen human-machine interface that can display heat load data, valve opening and closing status and cleaning process progress in real time, and supports manual setting of cleaning trigger threshold and pulse parameters.

[0012] Preferably, the connection end of the cleaning bypass pipeline to the slurry flow side is set corresponding to the slurry side header of the waste heat exchanger body 1, and a one-way valve is provided on the cleaning bypass pipeline.

[0013] Preferably, the end of the sewage pipe of the electric sewage valve 6 is connected to the desulfurization ditch or wastewater treatment system, and a filter assembly is connected in series on the sewage pipe.

[0014] Compared with the prior art, the present invention has the following beneficial effects: Online cleaning without affecting production: Relying on the dual-path design of the slurry circulation switching unit, the waste heat exchanger body can be isolated and cleaned online by switching the slurry flow path. The entire process does not require shutdown, ensuring continuous and stable operation of the desulfurization tower and avoiding production interruptions and economic losses caused by cleaning.

[0015] Highly efficient and thorough cleaning: The water-side pulse cleaning unit generates high-pressure pulsed water with a pressure of 0.4MPa to 1.0MPa and a frequency of 1 to 5 times per minute. The water hammer effect and strong shear force impact the inner wall of the heat exchange tube, which is far more effective in breaking and peeling off stubborn deposits than continuous low-pressure water flushing. At the same time, combined with the multi-cycle operation of pulse flushing-soaking softening-drainage controlled by the automatic control unit, the deposits can be further ensured to be completely removed and the heat exchange efficiency can be effectively restored.

[0016] Intelligent and automated: Heat load data is collected in real time by a heat load monitoring calorimeter. When the heat load decays to a preset threshold (such as 80% of the initial value), the automatic control unit can automatically trigger the cleaning program, transforming the cleaning from "periodic preventive" or "post-fault remedial" to "on-demand precision". This avoids the efficiency decline caused by insufficient cleaning and prevents energy waste caused by over-cleaning. In addition, the automatic control unit is equipped with a human-machine interface, which supports parameter setting and status monitoring, reducing manual intervention.

[0017] Safe, reliable, and long-lasting: It adopts a purely physical cleaning method, eliminating the need for chemical agents and completely avoiding the risk of corrosion of heat exchange tubes (especially duplex stainless steel heat exchange tubes) caused by chemical cleaning. It also avoids the problem of chemical residues polluting the desulfurization system. The entire cleaning process is executed by an automatic control unit according to preset logic, eliminating the risk of human error and extending the overall service life of the equipment. Attached Figure Description

[0018] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0019] Figure 1 This is a structural diagram of the present invention.

[0020] Legend: 1. Waste heat exchanger body; 2. Slurry circulation switching unit; 3. Water-side pulse cleaning unit; 4. Heat load monitoring calorimeter; 5. Automatic control unit; 6. Electric drain valve; 21. Slurry main line electric valve; 22. Slurry bypass inlet valve; 23. Slurry bypass outlet valve; 31. Flushing electric bypass valve; 32. Flushing pulse pressurization valve. Detailed Implementation

[0021] This application provides a desulfurization slurry waste heat exchanger with online pulse cleaning function, which effectively solves the technical problem that the heat exchange efficiency of existing desulfurization slurry waste heat exchangers decreases due to the deposition of solid particles in the desulfurization slurry on the inner wall of the heat exchange tube, and that existing methods such as manual disassembly and cleaning during shutdown, chemical cleaning, or continuous low-pressure water online cleaning cannot achieve efficient online cleaning without affecting the operation of the desulfurization tower.

[0022] Example like Figure 1 As shown, the overall technical solution in this application embodiment is as follows: To address the problems existing in the prior art, this utility model provides a desulfurization slurry waste heat exchanger with online pulse cleaning function. Its core is to achieve waste heat recovery and online high-efficiency cleaning through the integrated design and collaborative operation of each unit. The specific structure and working process are as follows: Waste heat exchanger body 1: Adopts a shell-and-tube structure, with the shell side being the slurry flow side (connected to the desulfurization tower slurry circulation system) and the tube side being the water flow side (connected to the waste heat recovery water circulation system); its heat exchange tubes are made of 2205 duplex stainless steel, which also has good Cl-resistance. - Its corrosion resistance and thermal conductivity make it suitable for the complex working conditions of desulfurization slurry.

[0023] Slurry circulation switching unit 2 includes a slurry main line electric valve 21, a slurry bypass inlet valve 22, a slurry bypass outlet valve 23, and supporting pipelines; wherein, the slurry main line is connected in parallel with the slurry flow side (for the slurry to directly bypass the heat exchanger), and the two ends of the slurry bypass are respectively connected to the inlet and outlet of the slurry flow side (for the slurry to flow through the heat exchanger for heat exchange). All three valves are electrically adjustable and can quickly respond to control signals.

[0024] Water-side pulse cleaning unit 3: Composed of flushing electric bypass valve 31, flushing pulse pressurization valve 32 and cleaning bypass pipeline; flushing electric bypass valve 31 and flushing pulse pressurization valve 32 are connected in series on the bypass on the water flow side. One end of the cleaning bypass pipeline is connected to the pipeline between the two valves, and the other end is set at the slurry side header of the waste heat exchanger body 1 (to ensure that high-pressure pulse water can enter each heat exchange tube evenly). A one-way valve is provided on the cleaning bypass pipeline (to prevent slurry backflow). The flushing pulse pressurization valve 32 is electrically adjustable, and the output pressure can be adjusted in the range of 0.4MPa-1.0MPa. The pulse frequency can be set in the range of 1 time / minute-5 times / minute.

[0025] Heat load monitoring calorimeter 4: An electromagnetic calorimeter is selected and installed on the inlet and outlet pipes on the water flow side of the waste heat exchanger body 1. The measurement accuracy reaches ±1.0%. It has a built-in data storage module and trend analysis module, which can collect water side temperature and flow data in real time, calculate instantaneous heat load, and upload the data to the automatic control unit 5.

[0026] Automatic control unit 5: Based on a programmable logic controller (PLC), it is equipped with a touch screen human-machine interface; it is connected to the slurry main electric valve 21, slurry bypass inlet valve 22, slurry bypass outlet valve 23, flushing electric bypass valve 31, flushing pulse pressurization valve 32 and heat load monitoring calorimeter 4 through signal lines; the operator can set parameters such as cleaning trigger threshold (e.g., 80% of the initial heat load), pulse pressure, cleaning cycle number, etc. on the human-machine interface, and at the same time view the heat load change curve, valve opening and closing status and cleaning process progress in real time.

[0027] Electric drain valve 6: installed on the bottom pipeline of the slurry flow side of the waste heat exchanger body 1 (to ensure that the sediment can be completely discharged). Its matching drain pipe end is connected to the desulfurization ditch, and a filter assembly is connected in series on the drain pipe (to prevent large particles of sediment from clogging the ditch pipeline).

[0028] Work process: The working process of this utility model is divided into a normal waste heat recovery mode and an online cleaning mode, as detailed below: Normal waste heat recovery mode: Automatic control unit 5 sends control signals: close the main slurry electric valve 21, and open the slurry bypass inlet valve 22 and the slurry bypass outlet valve 23; The hot slurry (temperature 40℃-60℃) discharged from the desulfurization tower enters the slurry flow side of the waste heat exchanger body 1 through the slurry bypass, and exchanges heat with the cooling water flowing in the opposite direction in the tube side. After absorbing heat, the cooling water is transported to the heating or process water preheating system (to achieve waste heat recovery); the slurry after heat exchange flows back to the desulfurization tower. The heat load monitoring calorimeter 4 continuously collects water-side temperature and flow data, calculates real-time heat load, and transmits the data to the automatic control unit 5 in real time for storage and trend analysis.

[0029] Online cleaning mode: When the heat load monitoring calorimeter 4 detects that the real-time heat load has decreased to 80% of the initial heat load (preset threshold), the automatic control unit 5 automatically triggers the online cleaning program. The specific steps are as follows: Slurry path switching and heat exchanger isolation: The automatic control unit 5 first closes the slurry bypass inlet valve 22 and the slurry bypass outlet valve 23, and then opens the slurry main line electric valve 21; the desulfurization slurry is switched to the slurry main line and flows directly back to the desulfurization tower, and the waste heat heat exchanger body 1 is completely isolated from the desulfurization slurry circulation system (the entire switching process takes less than 10 seconds and does not affect the normal operation of the desulfurization tower).

[0030] Pulse flushing: The automatic control unit 5 opens the flushing electric bypass valve 31 and the flushing pulse pressurization valve 32, and sets the output pressure of the flushing pulse pressurization valve 32 to 0.8MPa and the pulse frequency to 3 times / minute; the cooling water on the water flow side is converted into high-pressure pulse water through the flushing pulse pressurization valve 32, and injected into the slurry flow side of the waste heat exchanger body 1 through the cleaning bypass pipeline, flushing the inner wall of the heat exchange tube from top to bottom (for 30 minutes); at the same time, the electric drain valve 6 is opened, and the sewage containing sediment is discharged to the desulfurization ditch through the drain pipeline.

[0031] Soaking and softening: After rinsing, the automatic control unit 5 closes the flushing electric bypass valve 31, the flushing pulse pressure valve 32 and the electric drain valve 6, allowing the water to stand and soak in the slurry flow side for 60 minutes (allowing the water to fully penetrate into the stubborn scale layer and soften the deposits).

[0032] Sewage discharge: After soaking is completed, the automatic control unit 5 opens the electric sewage discharge valve 6 to discharge the turbid sewage containing softened sediment (for 8 minutes) until there is no obvious dirt in the slurry flow side.

[0033] Enhanced cleaning cycle: The automatic control unit 5 repeats the "pulse flushing-soaking softening-draining" steps twice (totaling 3 cycles) to ensure that the deposits on the inner wall of the heat exchange tube are completely removed.

[0034] Restoring waste heat recovery mode: After cleaning is completed, the automatic control unit 5 closes the electric drain valve 6, first closes the slurry main electric valve 21, and then opens the slurry bypass inlet valve 22 and the slurry bypass outlet valve 23; the desulfurization slurry re-enters the slurry flow side of the waste heat exchanger body 1, and the system resumes normal waste heat recovery operation.

[0035] This embodiment uses a purely physical cleaning method to avoid corrosion of the heat exchange tubes by chemical agents; at the same time, relying on automatic control and dual-path slurry circulation design, it achieves non-stop, high-efficiency cleaning and maintains the heat exchange efficiency of the heat exchanger for a long time, which is suitable for wet desulfurization systems in industries such as thermal power generation and chemical industry.

[0036] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A waste heat exchanger for desulfurized slurry with online pulse cleaning function, characterized in that, include: The waste heat exchanger body (1) is a shell-and-tube structure, with the shell side forming the slurry flow side and the tube side forming the water flow side. The slurry circulation switching unit (2) includes a slurry main line electric valve (21), a slurry bypass inlet valve (22), a slurry bypass outlet valve (23) and supporting pipelines. The slurry main line is connected in parallel with the slurry flow side, and the slurry bypass is connected in series with the slurry bypass inlet valve (22) and the slurry bypass outlet valve (23) and is connected in parallel with the slurry main line. The water-side pulse cleaning unit (3) includes a flushing electric bypass valve (31), a flushing pulse pressurization valve (32) and a cleaning bypass pipeline. The two valves are connected in series to the water flow side bypass. One end of the cleaning bypass pipeline is connected to the pipeline between the two valves and the other end is connected to the slurry flow side. Heat load monitoring calorimeter (4) is installed on the inlet and outlet pipes of the water flow side or the slurry flow side; The automatic control unit (5) is connected to the slurry main electric valve (21), slurry bypass inlet valve (22), slurry bypass outlet valve (23), flushing electric bypass valve (31), flushing pulse pressurization valve (32) and heat load monitoring calorimeter (4) via signal lines. The electric drain valve (6) has its inlet end connected to the bottom of the slurry flow side via a drain pipe.

2. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The heat exchange tubes of the waste heat exchanger body (1) are made of duplex stainless steel.

3. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The output pressure adjustment range of the flushing pulse pressurization valve (32) is 0.4MPa to 1.0MPa, and the pulse frequency adjustment range is 1 pulse / minute to 5 pulses / minute.

4. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The heat load monitoring calorimeter (4) is an electromagnetic calorimeter with a measurement accuracy of not less than ±1.5%, and has a built-in data storage module and trend analysis module.

5. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The heat load monitoring calorimeter (4) is an ultrasonic calorimeter with a measurement accuracy of not less than ±1.5% and has the function of bidirectional data interaction with the automatic control unit (5).

6. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The automatic control unit (5) includes a touch screen human-machine interface that can display heat load data, valve switch status and cleaning process progress in real time, and supports manual setting of cleaning trigger threshold and pulse parameters.

7. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The connection end of the cleaning bypass pipeline to the slurry flow side is set at the slurry side header of the waste heat exchanger body (1), and a one-way valve is provided on the cleaning bypass pipeline.

8. The desulfurization slurry waste heat exchanger with online pulse cleaning function according to claim 1, characterized in that, The end of the sewage pipe of the electric sewage valve (6) is connected to the desulfurization ditch or wastewater treatment system, and a filter assembly is connected in series on the sewage pipe.

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