Multi-stage cooling system for lurgi gasification wastewater

Abstract

The utility model relates to waste water cooling technical field especially, relates to a kind of multistage cooling system of lurgi gasification waste water, comprising: desalted water heat exchanger, circulating water heat exchanger, cooling tower, remote thermometer, temperature remote control regulating valve and the pipeline for conveying waste water;Desalted water heat exchanger has shell side and tube pass, the utility model is introduced into heat exchanger shell side by setting desalted water heat exchanger, 130 ℃ high ammonia nitrogen waste water discharged from lurgi gasifier, while the desalted water of initial temperature 25 ℃ is passed into tube pass, high ammonia nitrogen waste water is heated to desalted water using high-temperature waste heat, so that desalted water temperature rises to 70 ℃ after can be directly used in subsequent deoxidization process.In this process, high ammonia nitrogen waste water temperature is synchronously reduced to 65 ℃, both complete preliminary cooling of waste water, and the waste heat of waste water is fully recycled, replace the mode that traditional need additional energy consumption to heat desalted water.

Description

Technical Field

[0001] This utility model relates to the field of wastewater cooling technology, and in particular to a multi-stage cooling system for Lurgi gasification wastewater. Background Technology

[0002] Lurgi gasifiers generate high-ammonia-nitrogen wastewater during operation. If this wastewater is discharged directly without effective treatment, the ammonia-nitrogen will undergo a series of chemical reactions in the water, continuously consuming dissolved oxygen and causing the water body to fall into a state of hypoxia. This hypoxic environment will cause fish and other aquatic organisms to die due to lack of oxygen, thereby disrupting the aquatic ecological balance and causing serious environmental problems.

[0003] Currently, biological methods are a common and effective technique for treating high-ammonia-nitrogen wastewater. This method utilizes the metabolic activity of microorganisms, purifying pollutants in the water while the microorganisms themselves grow and reproduce. Specifically, ammonia nitrogen is converted into nitrogen gas through nitrification and denitrification, thereby reducing the ammonia nitrogen content in the wastewater. However, biological methods have strict requirements for the treatment environment. The core biological system needs to be maintained within a temperature range of 20℃ to 35℃. Temperatures that are too high or too low will significantly inhibit microbial activity, leading to decreased biological treatment efficiency and even system failure.

[0004] However, the initial temperature of the high-ammonia nitrogen wastewater discharged from the Lurgi gasifier is as high as 130℃, far exceeding the suitable temperature range of the biological treatment system. This directly leads to the inability of microorganisms to survive and prevents them from directly entering the biological treatment stage. While existing technologies have attempted to cool the high-temperature wastewater, they lack solutions that balance energy conservation and precise temperature control. On the one hand, the waste heat from the high-temperature wastewater is not effectively recovered, resulting in energy waste. On the other hand, conventional cooling methods (such as single-circulation water cooling) experience a significant decrease in cooling effect when the circulating water temperature rises in summer, making it difficult to stably control the wastewater temperature within the suitable range of 20℃ to 35℃. Ultimately, this affects the biological treatment effect and fails to meet the requirement for stable treatment of high-ammonia nitrogen wastewater to meet standards.

[0005] Therefore, it is necessary to provide a new multi-stage cooling system for Lurgi gasification wastewater to solve the above-mentioned technical problems. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a multi-stage cooling system for Lurgi gasification wastewater.

[0007] The multi-stage cooling system for Lurgi gasification wastewater provided by this utility model includes: a Lurgi gasifier, a demineralized water heat exchanger, a circulating water heat exchanger, a cooling tower, a remote thermometer, a remote temperature control valve, and pipelines for conveying wastewater. The demineralized water heat exchanger has a shell side and a tube side. The shell side inlet of the demineralized water heat exchanger is connected to the high-ammonia nitrogen wastewater outlet of the Lurgi gasifier via a pipeline, and is used to receive high-ammonia nitrogen wastewater at a temperature of 130°C. The tube side of the demineralized water heat exchanger is used to introduce demineralized water with an initial temperature of 25°C, and the high-ammonia nitrogen wastewater exchanges heat with the demineralized water in the shell side of the demineralized water heat exchanger. The inlet of the circulating water heat exchanger is connected to the shell side outlet of the demineralized water heat exchanger via a pipeline, and is used to receive demineralized water. The high-ammonia nitrogen wastewater is cooled by a heat exchanger; a remote thermometer is installed on the outlet pipe of the circulating water heat exchanger to detect the temperature of the high-ammonia nitrogen wastewater after treatment by the circulating water heat exchanger; a temperature remote control regulating valve is installed on a branch pipe between the outlet pipe of the circulating water heat exchanger and the cooling tower, and the outlet of the cooling tower is connected to the inlet of the biochemical treatment system through a pipe, and the outlet pipe of the circulating water heat exchanger is also directly connected to the inlet of the biochemical treatment system; the temperature remote control regulating valve is connected to the signal of the remote thermometer, and controls whether the high-ammonia nitrogen wastewater enters the cooling tower according to the temperature detected by the remote thermometer, so that the temperature of the high-ammonia nitrogen wastewater finally entering the biochemical treatment system is maintained at 20℃~35℃.

[0008] Preferably, after the high ammonia nitrogen wastewater completes heat exchange in the shell side of the demineralized water heat exchanger, the temperature drops from 130°C to 65°C; after the demineralized water completes heat exchange in the tube side of the demineralized water heat exchanger, the temperature rises from 25°C to 70°C, and the heated demineralized water is used in the subsequent deoxygenation process.

[0009] Preferably, the circulating water heat exchanger is used to cool the 65°C high ammonia nitrogen wastewater discharged from the shell-side outlet of the demineralized water heat exchanger to about 35°C.

[0010] Preferably, the control logic of the temperature remote control regulating valve is as follows: when the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer is higher than 35°C, the temperature remote control regulating valve is opened, and the high ammonia nitrogen wastewater enters the cooling tower for cooling through the branch pipeline; when the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer is lower than 35°C, the temperature remote control regulating valve is closed, and the high ammonia nitrogen wastewater enters the biochemical treatment system through the direct pipeline at the outlet of the circulating water heat exchanger.

[0011] Preferably, the cooling tower is used to assist in cooling the high ammonia nitrogen wastewater when the circulating water temperature is too high in summer, resulting in the circulating water heat exchanger not being effective in cooling the high ammonia nitrogen wastewater, so as to ensure that the wastewater temperature entering the biochemical treatment system meets the requirement of 20℃~35℃.

[0012] Compared with related technologies, the multi-stage cooling system for Lurgi gasification wastewater provided by this utility model has the following beneficial effects: By installing a demineralized water heat exchanger, the 130°C high-ammonia nitrogen wastewater discharged from the Lurgi gasifier is introduced into the shell side of the heat exchanger, while demineralized water with an initial temperature of 25°C is introduced into the tube side. The high-temperature waste heat from the high-ammonia nitrogen wastewater is used to heat the demineralized water, raising its temperature to 70°C, which can then be directly used in the subsequent deoxygenation process. During this process, the temperature of the high-ammonia nitrogen wastewater simultaneously drops to 65°C, achieving both initial cooling of the wastewater and full recovery and utilization of its waste heat. This replaces the traditional method of requiring additional energy to heat the demineralized water, significantly reducing the overall energy consumption of the process and meeting the industry's demand for energy conservation and emission reduction.

[0013] In the downstream stage of the circulating water heat exchanger, a coordinated structure involving a remote thermometer, a remote temperature control valve, and a cooling tower enables dynamic and precise control of the wastewater temperature. The circulating water heat exchanger can further cool the 65℃ wastewater to approximately 35℃, meeting the temperature requirements for biochemical treatment under normal operating conditions. When the circulating water temperature rises in summer and the cooling effect of the circulating water heat exchanger is insufficient, the remote thermometer monitors the wastewater temperature in real time. If the temperature exceeds 35℃, the remote temperature control valve automatically opens, guiding the wastewater into the cooling tower for auxiliary cooling. Once the temperature drops below 35℃, the valve closes, and the wastewater directly enters the biochemical system. This design ensures that, regardless of normal operating conditions or high-temperature summer conditions, the final wastewater temperature entering the biochemical system can be stably maintained within the suitable range of 20℃ to 35℃, effectively protecting microbial activity, avoiding a decrease in biochemical treatment efficiency due to temperature fluctuations, and ensuring stable and reliable treatment of high-ammonia nitrogen wastewater. Attached Figure Description

[0014] Figure 1 A schematic diagram of the multi-stage cooling system for Lurgi gasification wastewater provided by this utility model.

[0015] The following are labeled in the diagram: 1. Demineralized water heat exchanger; 2. Circulating water heat exchanger; 3. Cooling tower; 4. Remote thermometer; 5. Remote temperature control valve; 6. Branch pipeline; 7. Lurgi gasifier. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0017] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0018] Please see Figure 1A multi-stage cooling system for Lurgi gasification wastewater includes: a demineralized water heat exchanger 1, a circulating water heat exchanger 2, a cooling tower 3, a remote thermometer 4, a remote temperature control valve 5, and a pipeline 6 for conveying wastewater. The demineralized water heat exchanger 1 has a shell side and a tube side. The shell side inlet of the demineralized water heat exchanger 1 is connected to the high-ammonia nitrogen wastewater outlet of the Lurgi gasifier 7 via the pipeline 6, and is used to receive high-ammonia nitrogen wastewater at a temperature of 130°C. The tube side of the demineralized water heat exchanger 1 is used to introduce demineralized water with an initial temperature of 25°C. The high-ammonia nitrogen wastewater exchanges heat with the demineralized water in the tube side within the shell side of the demineralized water heat exchanger 1. The inlet of the circulating water heat exchanger 2 is connected to the tube side via the pipeline... The outlet pipe 6 of the circulating water heat exchanger 2 is connected to the shell-side outlet of the demineralized water heat exchanger 1 and is used to receive the high ammonia nitrogen wastewater cooled by the demineralized water heat exchanger 1. The remote temperature transmission thermometer 4 is installed on the outlet pipe 6 of the circulating water heat exchanger 2 and is used to detect the temperature of the high ammonia nitrogen wastewater after treatment by the circulating water heat exchanger 2. The remote temperature transmission control regulating valve 5 is installed on the branch pipe 6 between the outlet pipe 6 of the circulating water heat exchanger 2 and the cooling tower 3, and the outlet of the cooling tower 3 is connected to the inlet of the biochemical treatment system through the pipe 6. The outlet pipe 6 of the circulating water heat exchanger 2 is also directly connected to the inlet of the biochemical treatment system. The remote temperature transmission control regulating valve 5 is connected to the remote temperature transmission... The temperature is controlled by the remote thermometer 4 to determine whether the high-ammonia nitrogen wastewater enters the cooling tower 3, maintaining the temperature of the high-ammonia nitrogen wastewater entering the biochemical treatment system between 20°C and 35°C. After heat exchange in the shell side of the demineralized water heat exchanger 1, the temperature of the high-ammonia nitrogen wastewater drops from 130°C to 65°C. After heat exchange in the tube side of the demineralized water heat exchanger 1, the temperature of the demineralized water rises from 25°C to 70°C, and the heated demineralized water is used in the subsequent deoxygenation process. The circulating water heat exchanger 2 is used to cool the 65°C high-ammonia nitrogen wastewater discharged from the shell side outlet of the demineralized water heat exchanger 1 to approximately 35°C. The temperature remote control regulating valve 5... The control logic is as follows: when the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer 4 is higher than 35℃, the temperature remote control regulating valve 5 is opened, and the high ammonia nitrogen wastewater enters the cooling tower 3 for cooling through the branch pipe 6; when the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer 4 is lower than 35℃, the temperature remote control regulating valve 5 is closed, and the high ammonia nitrogen wastewater enters the biochemical treatment system through the direct pipe 6 at the outlet of the circulating water heat exchanger 2. The cooling tower 3 is used to provide auxiliary cooling for the high ammonia nitrogen wastewater when the circulating water temperature is too high in summer, resulting in the circulating water heat exchanger 2 not achieving the desired cooling effect on the high ammonia nitrogen wastewater, so as to ensure that the wastewater temperature entering the biochemical treatment system meets the requirement of 20℃~35℃.

[0019] The working principle of the multi-stage cooling system for Lurgi gasification wastewater provided by this utility model is as follows: This device aims to achieve precise temperature control of high ammonia nitrogen wastewater from Lurgi gasifiers to meet the 20℃~35℃ requirements for biochemical treatment and to recover waste heat. The overall workflow follows the logic of "waste heat recovery - preliminary cooling - temperature detection - dynamic temperature control - entering biochemical treatment," with each core component (1-6) working synergistically. The specific principles are as follows: In the waste heat recovery and preliminary cooling of demineralized water heat exchanger 1, the high-ammonia nitrogen wastewater generated by the Lurgi gasifier at a temperature of 130°C first enters the shell side of demineralized water heat exchanger 1 through pipeline 6 used for wastewater transport; simultaneously, demineralized water with an initial temperature of 25°C is introduced into the tube side of demineralized water heat exchanger 1. Inside demineralized water heat exchanger 1, the high-temperature, high-ammonia nitrogen wastewater in the shell side exchanges heat with the low-temperature demineralized water in the tube side: the heat of the high-ammonia nitrogen wastewater is transferred to the demineralized water, and its own temperature drops from 130°C to 65°C, completing the preliminary cooling; while the demineralized water absorbs heat and its temperature rises to 70°C, and is then transported to the subsequent deoxygenation process, realizing the efficient recovery and reuse of waste heat from the wastewater and reducing energy waste.

[0020] In the further cooling stage of the circulating water heat exchanger 2, the high ammonia nitrogen wastewater, initially cooled to 65°C by the demineralized water heat exchanger 1, enters the circulating water heat exchanger 2 through pipeline 6. The circulating water heat exchanger 2, through its built-in circulating water cooling system, performs a secondary cooling treatment on the 65°C high ammonia nitrogen wastewater. Under normal operating conditions, excluding the high temperatures of summer, the wastewater temperature can be stably reduced to around 35°C, initially meeting the temperature requirements of the biochemical treatment system.

[0021] In the stage of temperature detection and dynamic temperature control, a remote temperature transmission thermometer 4, a remote temperature control valve 5, and a cooling tower 3 work together. A fixed remote temperature transmission thermometer 4 on the outlet pipe 6 of the circulating water heat exchanger 2 monitors the temperature of the high-ammonia nitrogen wastewater after secondary cooling in real time and synchronously transmits the temperature signal to the remote temperature control valve 5. Based on the received temperature signal, the remote temperature control valve 5 controls the wastewater flow direction according to preset logic to achieve dynamic temperature control. If the remote thermometer 4 detects that the wastewater temperature is below 35℃ and meets the requirements for biochemical treatment, the temperature remote control regulating valve 5 will be closed, and the wastewater will directly enter the subsequent biochemical treatment system through the pipeline 6 at the outlet of the circulating water heat exchanger 2. If the remote thermometer 4 detects that the wastewater temperature is higher than 35°C, such as when the circulating water temperature rises in summer, causing the cooling effect of the circulating water heat exchanger 2 to decrease, the temperature remote control regulating valve 5 will open, and the wastewater will enter the cooling tower 3 through the branch pipe 6 for auxiliary cooling; after being cooled by the cooling tower 3, the wastewater temperature drops to below 35°C, and then it will be transported to the biochemical treatment system through the pipe 6.

[0022] Through the continuous process of "preliminary cooling - secondary cooling - dynamic temperature control" described above, the temperature of the high ammonia nitrogen wastewater entering the biological treatment system is always maintained within a suitable range of 20℃~35℃, ensuring the activity of microorganisms in the biological system, ensuring the stable progress of nitrification and denitrification processes, and achieving effective degradation of high ammonia nitrogen wastewater.

[0023] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A multi-stage cooling system for Lurgi gasification wastewater, characterized in that, include: The system includes a Lurgi gasifier (7), a demineralized water heat exchanger (1), a circulating water heat exchanger (2), a cooling tower (3), a remote thermometer (4), a temperature remote control valve (5), and branch pipes (6). The demineralized water heat exchanger (1) has an independent shell side and a tube side. The shell side inlet of the demineralized water heat exchanger (1) is connected to the high ammonia nitrogen wastewater outlet of the Lurgi gasifier (7) via a pipe to receive the high ammonia nitrogen wastewater discharged from the Lurgi gasifier (7) at a temperature of 130°C. The tube side of the demineralized water heat exchanger (1) is used to introduce demineralized water with an initial temperature of 25°C. The high ammonia nitrogen wastewater exchanges heat with the demineralized water in the tube side of the demineralized water heat exchanger (1) in the shell side. The inlet of the circulating water heat exchanger (2) is connected to the shell side outlet of the demineralized water heat exchanger (1) via a pipe to receive the high ammonia nitrogen wastewater cooled by heat exchange in the demineralized water heat exchanger (1). Ammonia nitrogen wastewater; the remote thermometer (4) is installed on the outlet pipe of the circulating water heat exchanger (2) to detect the temperature of the high ammonia nitrogen wastewater after treatment by the circulating water heat exchanger (2) in real time; the temperature remote control regulating valve (5) is installed on the branch pipe (6) extending from the outlet pipe of the circulating water heat exchanger (2), and the other end of the branch pipe (6) is connected to the inlet of the cooling tower (3), and the outlet of the cooling tower (3) is connected to the outlet pipe of the circulating water heat exchanger (2) through the pipe; the temperature remote control regulating valve (5) establishes a signal connection with the remote thermometer (4), and the temperature remote control regulating valve (5) controls whether the high ammonia nitrogen wastewater enters the cooling tower (3) according to the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer (4), so that the temperature of the high ammonia nitrogen wastewater entering the biochemical treatment system is maintained at 20℃~35℃.

2. The multi-stage cooling system for Lurgi gasification wastewater according to claim 1, characterized in that, After the high ammonia nitrogen wastewater completes heat exchange in the shell side of the demineralized water heat exchanger (1), the temperature drops from 130°C to 65°C; after the demineralized water completes heat exchange in the tube side of the demineralized water heat exchanger (1), the temperature rises from 25°C to 70°C, and the heated demineralized water is used for subsequent deoxygenation processes.

3. The multi-stage cooling system for Lurgi gasification wastewater according to claim 1, characterized in that, The circulating water heat exchanger (2) is used to cool the 65°C high ammonia nitrogen wastewater discharged from the shell side outlet of the demineralized water heat exchanger (1) to about 35°C.

4. The multi-stage cooling system for Lurgi gasification wastewater according to claim 1, characterized in that, The control logic of the temperature remote control regulating valve (5) is as follows: when the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer (4) is higher than 35°C, the temperature remote control regulating valve (5) is opened, and the high ammonia nitrogen wastewater enters the cooling tower (3) for cooling through the branch pipe (6); when the temperature of the high ammonia nitrogen wastewater detected by the remote thermometer (4) is lower than 35°C, the temperature remote control regulating valve (5) is closed, and the high ammonia nitrogen wastewater is directly discharged through the outlet of the circulating water heat exchanger (2).

5. The multi-stage cooling system for Lurgi gasification wastewater according to claim 1, characterized in that, The cooling tower (3) is used to assist in cooling the high ammonia nitrogen wastewater when the circulating water temperature is too high in summer, which causes the circulating water heat exchanger (2) to have an unsatisfactory cooling effect on the high ammonia nitrogen wastewater, so as to ensure that the wastewater temperature entering the biochemical treatment system meets the requirement of 20℃~35℃.

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