A sludge drying system based on temperature difference thermal energy

Abstract

This utility model discloses a sludge drying system using a temperature difference thermal energy method, belonging to the field of energy-saving and environmental protection technology. It includes: a heat source medium pipeline connected to the heat source side of a jacketed sludge dryer and / or a first heat exchanger; the jacketed sludge dryer connected to the heat source side of a small temperature difference heat exchanger via a steam channel; and the heating side of the first heat exchanger and / or the small temperature difference heat exchanger connected to the medium to be heated pipeline. This application achieves graded utilization of thermal energy through rematching the heat source, the heat-using end, and the heat transfer temperature difference in sludge drying, resulting in almost zero heat consumption in sludge drying and significantly reducing sludge drying costs.

Description

Technical Field

[0001] This utility model belongs to the field of energy-saving and environmental protection technology, and in particular to a sludge drying system using temperature difference heat energy. Background Technology

[0002] With the development of China's social economy and urbanization, the amount of urban sewage generated is constantly increasing, and the output of sludge, as a byproduct of sewage treatment, is also increasing accordingly. It is estimated that urban sewage treatment plants in my country currently discharge approximately 300,000 tons of dry sludge annually, and this figure is growing at a rate of about 10% per year. Improved sewage treatment efficiency will inevitably lead to a further increase in the amount of sludge.

[0003] Sludge drying and weight reduction is a necessary method to reduce the total amount of sludge and achieve subsequent harmless treatment or resource utilization of sludge. Currently, commonly used sludge drying methods can dewater sludge to a moisture content of 10% to 40%. However, sludge drying requires a large amount of heat energy or electricity. The steam consumption for sludge dewatering and weight reduction is 1.25 to 1.5 tons of steam per ton of weight reduction, or 220 to 280 kWh of electricity per ton of weight reduction. Utility Model Content

[0004] Purpose of the utility model: To provide a sludge drying system based on temperature difference thermal energy to solve the above-mentioned problems existing in the prior art.

[0005] Technical solution: A sludge drying system using temperature difference heat energy, comprising: a heat source medium pipeline, the heat source medium pipeline being connected to the heat source side of the jacketed sludge dryer and / or the first heat exchanger, the jacketed sludge dryer being connected to the heat source side of the small temperature difference heat exchanger via a steam channel, and the heating side of the first heat exchanger and / or the small temperature difference heat exchanger being connected to the medium to be heated pipeline.

[0006] Furthermore, the heat source medium pipeline includes: a heat source medium inlet pipeline, which is connected to the heat source side medium inlet of the jacketed sludge dryer and the first heat exchanger respectively, and the heat source side medium outlet of the jacketed sludge dryer and the first heat exchanger is connected to the heat source medium outlet pipeline respectively.

[0007] Furthermore, the heating medium pipeline includes: a heating medium inlet pipeline, which is connected to the heating side medium inlet of the small temperature difference heat exchanger and the first heat exchanger, respectively, and the heating side medium outlet of the small temperature difference heat exchanger and the first heat exchanger is connected to the heating medium outlet pipeline.

[0008] Furthermore, the heat source side medium outlet of the small temperature difference heat exchanger is connected to a vacuum pump.

[0009] Furthermore, the small temperature difference heat exchanger is a partitioned heat exchanger.

[0010] Furthermore, regulating valves are installed on the heat source side medium inlet and medium outlet of the jacketed sludge dryer, the heat source side medium inlet and medium outlet of the first heat exchanger, the heating side medium inlet and medium outlet of the first heat exchanger, and the heating side medium inlet and medium outlet of the small temperature difference heat exchanger.

[0011] Furthermore, the jacketed sludge dryer is equipped with a demister.

[0012] Furthermore, a dust collector or a demister is installed on the steam passage.

[0013] Furthermore, the jacketed sludge dryer and the small temperature difference heat exchanger are integrated into one structure.

[0014] Furthermore, the steam passage is a steam inlet or a steam pipeline.

[0015] Beneficial effects:

[0016] This application achieves graded utilization of thermal energy by rematching the heat source, the heat-using end, and the heat transfer temperature difference in sludge drying, thereby achieving almost zero heat consumption in sludge drying and significantly reducing the cost of sludge drying. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a system diagram of this utility model.

[0019] The attached diagram is labeled as follows: heat source medium pipeline 100, heat source medium inlet pipeline 110, heat source medium outlet pipeline 120, jacketed sludge dryer 200, first heat exchanger 300, steam passage 400, small temperature difference heat exchanger 500, medium to be heated pipeline 600, medium to be heated inlet pipeline 610, medium to be heated outlet pipeline 620, vacuum pump 700, regulating valve 800. Detailed Implementation

[0020] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0021] like Figure 1 and Figure 2As shown, a sludge drying system using a temperature difference thermal energy method includes: a heat source medium pipeline 100, which is connected to the heat source side of a jacketed sludge dryer 200 and / or a first heat exchanger 300; the jacketed sludge dryer 200 is connected to the heat source side of a small temperature difference heat exchanger 500 via a steam channel 400; and the heating side of the first heat exchanger 300 and / or the small temperature difference heat exchanger 500 is connected to a medium to be heated pipeline 600. The heat source medium pipeline 100 includes: a heat source medium inlet pipeline 110, which is connected to the heat source side medium inlets of the jacketed sludge dryer 200 and the first heat exchanger 300 respectively; and the heat source side medium outlets of the jacketed sludge dryer 200 and the first heat exchanger 300 are connected to a heat source medium outlet pipeline 120 respectively. The heating medium pipeline 600 includes a heating medium inlet pipeline 610, which is connected to the heating side medium inlets of the small temperature difference heat exchanger 500 and the first heat exchanger 300, respectively. The heating side medium outlets of the small temperature difference heat exchanger 500 and the first heat exchanger 300 are connected to the heating medium outlet pipeline 620, respectively. The heat source side medium outlet of the small temperature difference heat exchanger 500 is connected to the vacuum pump 700. The small temperature difference heat exchanger 500 is a partition wall type heat exchanger. A regulating valve 800 is installed on the heat source side medium inlet and outlet of the jacketed sludge dryer 200, the heat source side medium inlet and outlet of the first heat exchanger 300, the heating side medium inlet and outlet of the first heat exchanger 300, and the heating side medium inlet and outlet of the small temperature difference heat exchanger 500. A demister is installed inside the jacketed sludge dryer 200. A dust collector or demister is installed on the steam channel 400. The jacketed sludge dryer 200 and the small temperature difference heat exchanger 500 are an integral structure. The steam channel 400 is a steam inlet or steam pipeline. The demister can be integrated into the jacketed sludge dryer 200 or the small temperature difference heat exchanger 500. When the jacketed sludge dryer 200 and the small temperature difference heat exchanger 500 are separate units, the demister can also be installed on the steam channel 400. The dust collector can be a mechanical dust collector, a washing dust collector, a filter dust collector, an electrostatic dust collector, or a magnetic dust collector, depending on the actual scenario.

[0022] The heat source medium pipeline 100 contains the heat source medium, which can be a liquid or a gas. The heat source medium pipeline 100 can independently power either the jacketed sludge dryer 200 or the first heat exchanger 300, achieving efficient heat exchange and improving drying efficiency. Alternatively, it can simultaneously power both the jacketed sludge dryer 200 and the first heat exchanger 300, with precise control of the heat source medium flow rate via a regulating valve 800 to ensure temperature stability and optimize heat exchange. The regulating valve 800 can employ an intelligent control system to automatically adjust the flow rate of the heat source medium entering the jacketed sludge dryer 200 and the first heat exchanger 300. This application also includes a temperature sensor for real-time monitoring of the temperature in each pipeline, ensuring the system operates at its optimal state. The jacketed sludge dryer 200 has a jacket structure on its sidewalls to provide heat for sludge flash evaporation. A circulating heat source medium within the jacket rapidly increases the sludge temperature through efficient heat conduction, promoting sludge moisture evaporation and achieving efficient drying. Flow channels within the jacket ensure uniform distribution of the heat source medium, improving heat exchange efficiency. The flow channels are spiral or mesh structures to enhance the fluidity of the heat source medium, preventing localized overheating or cooling and ensuring uniform heating of the sludge, further optimizing the drying effect. The first heat exchanger 300 can be a plate heat exchanger or a shell-and-tube heat exchanger, selected according to actual needs to maximize heat exchange efficiency. The small temperature difference heat exchanger 500 uses high-efficiency heat transfer materials to improve heat exchange efficiency and reduce energy consumption. The small temperature difference heat exchanger 500 is a steam-water heat exchanger, utilizing the temperature difference between steam and water for efficient heat exchange, reducing heat loss and improving the overall system thermal efficiency. The vacuum pump 700 maintains a low-pressure environment within the system, accelerating sludge moisture evaporation and further enhancing the drying effect. The jacketed sludge dryer 200 and the small temperature difference heat exchanger 500 described in this application can be an integrated structure or a separate structure, which can be flexibly configured according to actual needs to ensure that the system adapts to different working conditions. The integrated structure has a compact design, reduces installation space, and improves overall operational stability. The separate structure facilitates maintenance and replacement of components, extending the service life of the equipment.

[0023] Example 1: When the heat source medium is steam and the heat source temperature is 130℃, and the medium to be heated is liquid, it is necessary to raise the temperature of the medium to be heated from 45℃ to 65℃.

[0024] Workflow: First, steam at 130°C enters the jacketed sludge dryer 200 through the heat source medium pipeline 100. Inside the jacketed sludge dryer 200, the sludge is heated, evaporating into 105°C water vapor. The steam then enters the small temperature difference heat exchanger 500, where it exchanges heat with the medium to be heated, raising the medium temperature to 65°C. Simultaneously, the steam condenses into water and is discharged. Throughout this process, the operating conditions remain unchanged on both the heat source and heating sides. Sludge drying with "zero" heat consumption is achieved solely through the cascade utilization of the temperature difference heat energy of the heat source water.

[0025] Based on the original system's heat source medium pipeline 100, first heat exchanger 300, and heated medium pipeline 600 having a heat exchange capacity of 10 GJ / h, and according to the operating conditions of Example 1, the average heat exchange temperature difference between the media on both sides of the first heat exchanger 300 is 75℃, with a heat transfer coefficient calculated at 2500 W / m².℃, and the heat exchange area of ​​the original system's first heat exchanger 300 is 15 m². After adding the sludge drying system, the average heat exchange temperature difference between the media on both sides of 200 is 50℃, with a heat transfer coefficient calculated at 2500 W / m².℃, and the heat exchange area of ​​200 is 22 m². This process can dry 5.6 t / h of wet sludge with 80% moisture content to dry sludge with 30% moisture content, evaporating 4 t / h of water. The volume of the dried sludge is significantly reduced, facilitating subsequent treatment and resource utilization. The overall thermal efficiency of the system is improved by 20%, achieving energy saving and emission reduction, and meeting environmental protection requirements.

[0026] Example 2: When the heat source medium is steam and the heat source temperature is 95℃, and the medium to be heated is liquid, it is necessary to raise the temperature of the medium to be heated from 45℃ to 65℃.

[0027] Workflow: First, steam at 95°C enters the jacketed sludge dryer 200 through the heat source medium pipeline 100. Inside the jacketed sludge dryer 200, the sludge is heated, evaporating into 70°C water vapor. The steam then enters the small temperature difference heat exchanger 500, where it exchanges heat with the medium to be heated, raising the medium temperature to 65°C. Simultaneously, the steam condenses into water and is discharged. During this process, a vacuum pump 700 is added to maintain a low system pressure, allowing the sludge to evaporate rapidly at a lower temperature, further reducing energy consumption. This is achieved through optimized heat exchange processes.

[0028] Based on the original system's heat source medium pipeline 100, first heat exchanger 300, and medium to be heated pipeline 600 having a heat exchange capacity of 10 GJ / h, according to the operating conditions of Example 2, the average heat exchange temperature difference between the media on both sides of the first heat exchanger 300 is 30℃, the heat transfer coefficient is calculated at 2500 W / m².℃, and the heat exchange area of ​​the first heat exchanger 300 is 37 m². After adding the sludge drying system, the average heat exchange temperature difference between the media on both sides of 200 is 15℃, the heat transfer coefficient is calculated at 2500 W / m².℃, and the heat exchange area of ​​200 is 74 m². This process can dry 5.6 t / h of wet sludge with 80% moisture content to dry sludge with 30% moisture content, evaporating 4 t / h of water.

[0029] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A thermosiphon thermal energy method sludge drying system, comprising: The heat source medium pipeline (100) is characterized in that the heat source medium pipeline (100) is connected to the heat source side of the jacketed sludge dryer (200) and / or the first heat exchanger (300), the jacketed sludge dryer (200) is connected to the heat source side of the small temperature difference heat exchanger (500) through the steam channel (400), and the heating side of the first heat exchanger (300) and / or the small temperature difference heat exchanger (500) is connected to the medium pipeline (600) to be heated.

2. The thermal energy sludge drying system of claim 1, wherein, The heat source medium pipeline (100) includes: a heat source medium inlet pipeline (110), which is connected to the heat source side medium inlet of the jacketed sludge dryer (200) and the first heat exchanger (300), respectively, and the heat source side medium outlet of the jacketed sludge dryer (200) and the first heat exchanger (300) is connected to the heat source medium outlet pipeline (120).

3. The thermal energy sludge drying system of claim 1 or 2, wherein, The heating medium pipeline (600) includes: a heating medium inlet pipeline (610), which is connected to the heating side medium inlet of the small temperature difference heat exchanger (500) and the first heat exchanger (300), respectively, and the heating side medium outlet of the small temperature difference heat exchanger (500) and the first heat exchanger (300) is connected to the heating medium outlet pipeline (620).

4. The thermal energy sludge drying system of claim 1, wherein, The heat source side medium outlet of the small temperature difference heat exchanger (500) is connected to the vacuum pump (700).

5. The thermal energy sludge drying system of claim 1, wherein, The small temperature difference heat exchanger (500) is a partition wall heat exchanger.

6. The thermal energy sludge drying system of claim 3, wherein, The jacketed sludge dryer (200) has regulating valves (800) installed on the heat source side medium inlet and medium outlet, the first heat exchanger (300) heat source side medium inlet and medium outlet, the first heat exchanger (300) heating side medium inlet and medium outlet, and the small temperature difference heat exchanger (500) heating side medium inlet and medium outlet.

7. The thermal energy sludge drying system of claim 1, wherein, The jacketed sludge dryer (200) is equipped with a demister.

8. The thermal energy sludge drying system of claim 1, wherein, A dust collector or a demister is installed on the steam passage (400).

9. The thermal energy sludge drying system of claim 1, wherein, The jacketed sludge dryer (200) and the small temperature difference heat exchanger (500) are integrated into one structure.

10. The thermal energy sludge drying system of claim 1, wherein, The steam passage (400) is a steam inlet or a steam pipeline.

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