Device for heating alkali liquor by using waste heat of steam heat exchanger

Abstract

The utility model discloses a device for heating alkali liquor by using waste heat of a steam heat exchanger, which belongs to the technical field of sludge treatment and comprises a steam heat exchange system, an alkali liquor conveying system, an alkali liquor heat exchange system and a control system, the steam heat exchange system is connected with the alkali liquor heat exchange system through a pipeline and conveys high-temperature condensate water to the alkali liquor heat exchange system. The alkali liquor heat exchange system is arranged in the alkali liquor conveying system in a sealed mode, and heat exchange is achieved through high-temperature condensate water and alkali liquor in the alkali liquor conveying system. The control system controls the flow of the high-temperature condensate water output by the steam heat exchange system. The device for heating the alkali liquor by utilizing the waste heat of the steam heat exchanger can effectively solve the problems that an electric heater is adopted for heating the alkali liquor in the prior art, the power consumption is high, and meanwhile, the alkali liquor is easy to crystallize, so that a pipeline is blocked, and production halt accidents are caused; energy waste caused by the fact that energy of the steam heat exchanger in the same production line system is not effectively utilized is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of sludge treatment technology. Specifically, it relates to a device for heating alkaline solution using waste heat from a steam heat exchanger. Background Technology

[0002] In sludge treatment, the alkali solution system is used to adjust the pH value of the sludge, which is crucial for the stable operation of subsequent treatment processes. However, traditional alkali solution systems have several problems. On the one hand, the electric heaters for the alkali storage tanks and auxiliary pipelines consume a lot of energy; for example, common electric heaters have a power of 30KW*2, long intermittent operation time, and high daily power consumption, leading to increased operating costs. On the other hand, electric heating can easily cause the solution to crystallize, resulting in pipeline blockage and potentially causing production shutdowns, affecting the continuity and stability of production.

[0003] Meanwhile, the flue gas outlet of the first phase of the sludge plant uses a steam heat exchanger for tail flue gas heat exchange, which produces condensate at a high temperature. For example, the condensate temperature at the tube-side outlet of the first-stage heat exchanger is about 120°C, and the condensate temperature at the tube-side outlet of the second-stage heat exchanger is about 180°C. However, this waste heat is not being effectively utilized, resulting in energy waste. Utility Model Content

[0004] The purpose of this utility model is to address the aforementioned shortcomings by providing a device for heating alkaline solution using waste heat from a steam heat exchanger. This solves the problems of existing alkaline solution heating technologies that use electric heaters, resulting in high power consumption and easy crystallization of the alkaline solution, leading to pipeline blockage and subsequent production stoppages; and the energy waste caused by the ineffective utilization of the energy in the steam heat exchanger within the same production line system. To achieve the above objectives, this utility model provides the following technical solution:

[0005] A device for heating alkaline solution using waste heat from a steam heat exchanger includes a steam heat exchange system, an alkaline solution delivery system, an alkaline solution heat exchange system, and a control system. The steam heat exchange system is connected to the alkaline solution heat exchange system via pipelines to deliver high-temperature condensate to the alkaline solution heat exchange system. The alkaline solution heat exchange system is sealed within the alkaline solution delivery system and exchanges heat with the alkaline solution inside through the high-temperature condensate. The control system controls the flow rate of the high-temperature condensate output by the steam heat exchange system.

[0006] Furthermore, the alkali solution delivery system includes an alkali solution storage tank and a delivery pipeline; the alkali solution in the alkali solution storage tank is connected to the subsequent sludge treatment process through the delivery pipeline, and the alkali solution is delivered to adjust the pH value of the sludge.

[0007] Furthermore, the alkali heat exchange system is a serpentine coil heat exchanger, which is sealed inside the alkali storage tank and used to heat the alkali.

[0008] Furthermore, the steam heat exchange system includes a steam heat exchanger assembly and a condensate pipe; the condensate generated by the steam heat exchanger assembly is connected to a serpentine coil heat exchanger and a water tank respectively through the condensate pipe.

[0009] Furthermore, the control system includes a controller, a temperature sensor, and a regulating valve; the temperature sensor is used to detect the temperature of the alkali solution; the regulating valve is installed in the condensate pipe; and the controller controls the opening degree of the regulating valve by receiving feedback from the temperature sensor.

[0010] Furthermore, the serpentine coil heat exchanger includes several layers of heat exchange tubes, with a spacing of 3 to 4 mm between adjacent layers.

[0011] Furthermore, the regulating valve is a valve with pressure resistance, high temperature resistance, and equal percentage flow characteristics.

[0012] Furthermore, the steam heat exchanger assembly includes a primary heat exchanger and a secondary heat exchanger; the condensate from the tube-side outlet of the primary heat exchanger and the condensate from the tube-side outlet of the secondary heat exchanger are collected and transported to a condensate pipeline.

[0013] Furthermore, the alkali delivery system also includes a metering pump; the metering pump is installed on the delivery pipeline to control the output of alkali and precisely adjust the pH value of the sludge.

[0014] Furthermore, the control system precisely controls the opening of the regulating valve by monitoring changes in the alkali solution temperature, thereby achieving precise control of the alkali solution temperature and keeping the temperature fluctuation range within a controllable range.

[0015] The beneficial effects of this utility model are:

[0016] 1. Significant energy savings: By utilizing the waste heat of the condensate from the steam heat exchanger to heat the alkali solution, the operating time of the electric heater in the alkali solution system is greatly reduced, resulting in a significant increase in energy savings and a reduction in the company's energy costs.

[0017] 2. Excellent anti-clogging effect: By stably controlling the temperature of the alkali solution, the crystallization phenomenon of the alkali solution is effectively avoided, the risk of pipeline blockage is reduced, continuous and stable production is ensured, and the cost of downtime maintenance is reduced.

[0018] 3. Safety and environmental protection: Indirect heating avoids the generation of alkaline vapors, reduces safety risks, and also reduces pollutant emissions caused by equipment failure, thus improving environmental protection standards.

[0019] 4. High adaptability: The serpentine coil heat exchanger can be flexibly designed according to the needs of the alkaline solution system, and the regulating valve can accurately control it, making it suitable for different working conditions and ensuring stable and efficient system operation. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the present invention;

[0021] In the attached diagram: 1. Alkali storage tank; 2. Delivery pipeline; 3. Serpentine coil heat exchanger; 4. Steam heat exchanger assembly; 5. Condensate pipeline; 6. Controller; 7. Temperature sensor; 8. Water tank; 9. Regulating valve; 10. Heat exchange tube; 11. Metering pump. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] Example:

[0025] See attached Figure 1 A device for heating alkaline solution using waste heat from a steam heat exchanger is disclosed for use in existing sludge treatment systems. The steam heat exchanger system provides the heat source and is selected according to the application scenario. In this embodiment, the steam heat exchanger system is preferably a steam heat exchanger assembly 4. The flue gas outlet of the sludge plant undergoes tail-end flue gas heat exchange through the steam heat exchanger. The steam heat exchanger assembly 4 includes a primary heat exchanger and a secondary heat exchanger. The condensate output from the primary and secondary heat exchangers has a high temperature and can be used for heat exchange of the alkaline solution. The alkaline solution conveying system is used to transport the alkaline solution to the subsequent sludge treatment stage to adjust the pH value of the sludge. The alkaline solution heat exchange system is used to exchange heat between the high-temperature condensate from the steam heat exchanger assembly and the alkaline solution to realize the heating process of the alkaline solution, avoiding the problem of solution crystallization and pipeline blockage that is easily caused by electric heating. In this embodiment, the control system further controls the temperature of the alkaline solution by controlling the flow rate of the high-temperature condensate output from the steam heat exchanger system. It is preferable to set a temperature sensor 7 for feedback control to achieve controllable alkaline solution temperature within a certain range and realize automated management.

[0026] The alkali solution delivery system includes an alkali solution storage tank 1, a delivery pipeline 2, and a metering pump 11 installed on the delivery pipeline 2. The alkali solution heat exchange system heats the alkali solution in the alkali solution storage tank 1 and then connects it to the subsequent sludge treatment stage through the delivery pipeline 2. The metering pump 11 controls the output amount of alkali solution and precisely regulates the pH value of the sludge. The metering pump 11 is electrically connected to the control system and can be remotely controlled or automatically controlled through the control system.

[0027] The alkali heat exchange system is a serpentine coil heat exchanger 3, which is installed inside the alkali storage tank 1. In this embodiment, the coil is made of 316L stainless steel, with a diameter of 20mm, a wall thickness of 2mm, and a length of 500mm. It is a multi-layer heat exchange tube 10 wound in a spiral pattern, with the interlayer spacing controlled at 3-4mm. Its specific structure can be flexibly designed according to different needs to ensure sufficient and uniform contact with the alkali. This serpentine coil heat exchanger 3 is used for heat exchange between the condensate of the steam heat exchanger and the alkali, which can avoid the generation of alkali vapor, ensure the safe and stable operation of the system, and improve heat exchange efficiency.

[0028] The steam heat exchange assembly also includes a condensate pipe 5, which is connected to the liquid inlet of the serpentine coil heat exchanger 3 and the water tank 8 respectively. The condensate after heat exchange in the serpentine coil heat exchanger 3 continues to flow back to the water tank 8 for storage. In this embodiment, a regulating valve 9 with a pressure resistance of 1.6MPa, high temperature resistance, and equal percentage flow characteristics is installed on the condensate pipe 5 to precisely control the condensate flow rate to adapt to the heating requirements of the alkali system under different operating conditions and ensure the stability of the alkali temperature.

[0029] Preferably, this embodiment improves upon existing electric heating methods, allowing it to work in conjunction with or independently of the heating method, and further includes a safety protection system: the alkali storage tank 1 and heating pipes are made of corrosion-resistant and well-sealing materials, such as fluororubber gaskets, to ensure airtightness; forced ventilation equipment is provided, with the ventilation volume calculated and determined based on the space size and the amount of alkali vapor generated; the ventilation pipes are made of alkali-resistant materials, such as fiberglass; operators are equipped with personal protective equipment such as face shields, protective clothing, and protective gloves; the face shield lenses are made of anti-fog and alkali-resistant materials, the protective clothing is made of breathable and alkali-resistant fabric, and the gloves are made of nitrile rubber.

[0030] The control system includes a controller 6, a temperature sensor 7, and a regulating valve 9 installed on the condensate pipe 5. The temperature sensor 7 is installed on the alkali storage tank 1 to monitor the alkali temperature parameter. The controller 6 controls the opening of the regulating valve 9 by monitoring the temperature change of the alkali inside the tank, so as to achieve precise control of the alkali temperature and keep the alkali temperature fluctuation range within a controllable range.

[0031] In practical applications at sludge treatment plants, the operating parameters of the steam heat exchangers are first monitored to obtain data such as the temperature, pressure, and flow rate of the condensate at the tube-side outlets of the primary and secondary heat exchangers. For example, the average temperature of the primary condensate is 121.5℃, with a flow rate of approximately 500 kg / h, while the average temperature of the secondary condensate is 178.3℃, with a flow rate of approximately 1000 kg / h. Simultaneously, the current status of the alkali solution system is investigated, including the relevant parameters of alkali storage tank 1 and its auxiliary pipelines, as well as the operating status of the electric heater.

[0032] Based on the obtained data and survey results, a serpentine coil heat exchanger 3 was installed inside the alkali storage tank 1 to ensure good thermal contact between the coil and the tank wall and to ensure that the tank's sealing performance was not affected. A condensate pipe 5 connecting the steam heat exchanger and the serpentine coil heat exchanger 3 was laid, made of corrosion-resistant material, and a regulating valve 9 was installed to accurately control the condensate flow rate.

[0033] During the system commissioning phase, the regulating valve 9 on the condensate pipe 5 of the steam heat exchanger was slowly opened to gradually increase the flow rate. Simultaneously, the control system monitored changes in the alkali temperature and tank pressure (further monitoring was performed using a pressure sensor connected to the controller 6). The opening of the regulating valve 9 was adjusted via the controller 6 to stabilize the alkali temperature near the set target temperature (e.g., 21℃), with fluctuations controlled within ±2℃. During trial operation, the normal production conditions of the sludge plant were simulated, and system operating data was continuously monitored. Problems were addressed promptly, such as optimizing the heat exchanger efficiency and fine-tuning the opening of the regulating valve 9 to address slight crystallization of the alkali under low-temperature, high-concentration conditions.

[0034] Working principle:

[0035] High-temperature condensate from the steam heat exchanger is transported to the serpentine coil heat exchanger 3 via condensate pipe 5. During its flow within the coil, heat is conducted through the coil wall to the outer wall, and then transferred to the alkaline solution outside the coil via heat convection. The controller 6 precisely controls the opening of the regulating valve 9 based on data collected by temperature sensors 7, thereby adjusting the condensate flow rate and achieving precise control of the alkaline solution temperature. The alkaline solution is uniformly heated during circulation, and after reaching the appropriate temperature for adjusting the sludge pH, it is transported to the sludge treatment stage via metering pump 11. The safety protection system prevents alkaline vapor leakage during equipment operation, ensuring the safety of personnel, equipment, and the environment.

[0036] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. A device for heating alkaline solution using waste heat from a steam heat exchanger, characterized in that: It includes a steam heat exchange system, an alkali solution delivery system, an alkali solution heat exchange system, and a control system; the steam heat exchange system is connected to the alkali solution heat exchange system through pipelines to deliver high-temperature condensate to the alkali solution heat exchange system; the alkali solution heat exchange system is sealed in the alkali solution delivery system and achieves heat exchange with the internal alkali solution through the high-temperature condensate; the control system controls the flow rate of the high-temperature condensate output by the steam heat exchange system.

2. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 1, characterized in that: The alkali solution delivery system includes an alkali solution storage tank (1) and a delivery pipeline (2); the alkali solution in the alkali solution storage tank (1) is connected to the subsequent sludge treatment process through the delivery pipeline (2) to deliver the alkali solution for adjusting the pH value of the sludge.

3. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 2, characterized in that: The alkali heat exchange system is a serpentine coil heat exchanger (3), which is sealed inside the alkali storage tank (1) and used to heat the alkali.

4. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 3, characterized in that: The steam heat exchange system includes a steam heat exchanger assembly (4) and a condensate pipe (5); the condensate generated by the steam heat exchanger assembly (4) is connected to the serpentine coil heat exchanger (3) and the water tank (8) respectively through the condensate pipe (5).

5. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 4, characterized in that: The control system includes a controller (6), a temperature sensor (7), and a regulating valve (9); the temperature sensor (7) is used to detect the temperature of the alkali solution; the regulating valve (9) is installed in the condensate pipe (5); the controller (6) controls the opening degree of the regulating valve (9) by receiving feedback from the temperature sensor (7).

6. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 5, characterized in that: The serpentine coil heat exchanger (3) includes several layers of heat exchange tubes (10), and the distance between two adjacent layers of heat exchange tubes (10) is 3-4 mm.

7. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 6, characterized in that: The regulating valve (9) is a valve with pressure resistance, high temperature resistance, and equal percentage flow characteristics.

8. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 7, characterized in that: The steam heat exchanger assembly (4) includes a primary heat exchanger and a secondary heat exchanger; the condensate from the tube-side outlet of the primary heat exchanger and the condensate from the tube-side outlet of the secondary heat exchanger are collected and transported to the condensate pipe (5).

9. The device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 8, characterized in that: The alkaline solution delivery system also includes a metering pump (11); the metering pump (11) is installed on the delivery pipeline (2) to control the alkaline solution output and precisely adjust the pH value of the sludge.

10. A device for heating alkaline solution using waste heat from a steam heat exchanger according to claim 9, characterized in that: The control system precisely controls the opening of the regulating valve (9) by monitoring the temperature change of the alkali solution, thereby achieving precise control of the alkali solution temperature and keeping the temperature fluctuation range of the alkali solution within a controllable range.

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