A waste heat recovery deaeration system

Abstract

The utility model discloses a waste heat recovery deoxidization system. The system includes external steam input device, boiler feed water tank (1), deoxygenation groove (2), heat exchanger (3), condensate recovery groove (4), external steam heat exchanger (5), wherein external steam input device is connected with external steam heat exchanger (5), boiler feed water tank (1) is connected with heat exchanger (3), deoxygenation groove (2) is connected with heat exchanger (3) respectively, external steam heat exchanger (5), condensate recovery groove (4) is set in heat exchanger (3) export, is used for collecting condensate. The utility model discloses through setting heat exchanger before boiler feed water enters deoxygenation groove, and utilizes the venting steam of deoxygenation groove and external steam as heat source, preheats boiler feed water to superheated state and sprays under pressure condition, realizes the effective recycling of heat, reduces the consumption of external supply heating steam, can reduce steam consumption 20~25%.

Description

[0001] Technical Field

[0002] This utility model belongs to the field of waste heat recovery technology, specifically a waste heat recovery and deoxygenation system.

[0003] Background Technology

[0004] In industrial production, waste heat boilers are important heat energy recovery devices, and their feedwater deoxygenation system plays a crucial role in the overall system's operational efficiency and environmental protection. Currently, commonly used deoxygenation methods mainly include thermal deoxygenation and chemical deoxygenation. Chemical deoxygenation has advantages such as thorough deoxygenation, reliable effect, low equipment investment cost, flexible operation, and strong adaptability. However, the consumption of chemicals is also a considerable expense, and it may introduce additional impurities, causing certain impacts on equipment and the environment. Thermal deoxygenation, on the other hand, uses steam to heat the boiler feedwater to boiling, reducing the partial pressure of oxygen in the gas phase, thereby achieving deoxygenation. However, this method has significant drawbacks: for example, the direct discharge of large amounts of vented steam wastes heat, reduces the overall system efficiency, and also wastes clean water. In addition, the condensate from the vented steam in the environment may cause corrosion of steel structures or algae growth on the surface of concrete structures, and the mixing process of steam in water causes large equipment vibrations, shortens equipment lifespan, and results in small deoxygenation surface area and low deoxygenation efficiency.

[0005] Existing deaeration system designs fail to fully utilize the vented steam generated by the system, often requiring the consumption of large amounts of externally supplied heating steam. This not only increases operating costs but also hinders the achievement of energy conservation and environmental protection goals. Furthermore, the condensate generated during deaeration is typically discharged directly, while this clean water could be reused as demineralized water, further reducing system operating costs. Therefore, how to effectively utilize vented steam, improve deaeration efficiency, extend equipment lifespan, and simultaneously achieve the recycling of clean resources has become a pressing technical problem that needs to be solved.

[0006] To address the aforementioned issues, several improvements have been proposed, such as using a heat exchanger to preheat boiler feedwater using vented steam from the deaerator. This method reduces the consumption of externally supplied heating steam and utilizes the condensate as demineralized water, achieving water resource recycling. However, these solutions still have limitations in practical applications, such as complex heat exchanger design, inconvenient installation and maintenance, and small steam-water contact area. Therefore, developing a simple and efficient deaerator system that can fully utilize vented steam, recycle condensate, and ensure stable operation and ease of use has become an important direction for the development of waste heat boiler deaerator technology. Utility Model Content

[0007] The purpose of this invention is to address at least one of the following problems in the existing technology: waste heat from vented steam in waste heat boiler deaeration systems, ineffective recycling of clean water, complex heat exchanger design and inconvenient maintenance, high vibration from direct steam injection damaging equipment, and small water-steam contact deaeration area. This invention provides a waste heat recovery deaeration system. In this system, the generated vented steam is cooled into condensate and reused as demineralized water. An external steam heat exchanger is added to transfer the heat source steam, reducing system operating costs. Furthermore, intelligent control and real-time monitoring devices are added, allowing for dynamic adjustment of deaeration parameters based on production load, thereby increasing deaeration efficiency and system operational stability.

[0008] To achieve the purpose of this utility model, the specific technical solution adopted is as follows:

[0009] A waste heat recovery and deoxygenation system includes an external steam input device, a boiler feedwater tank, a deoxygenation tank, a heat exchanger, a condensate recovery tank, and an external steam heat exchanger.

[0010] An external steam input device is connected to an external steam heat exchanger, allowing external steam to exchange heat there.

[0011] The deaerator is connected to an external steam heat exchanger and a heat exchanger, respectively.

[0012] External steam heat exchanger and heat exchanger connection;

[0013] The boiler feedwater tank is connected to the heat exchanger;

[0014] The top of the deaerator is equipped with a steam outlet, which is connected to the heat exchanger via a pipe.

[0015] The condensate recovery tank is located at the heat exchanger outlet and is used to collect condensate.

[0016] Furthermore, in the aforementioned waste heat recovery and deoxygenation system, the system also includes a control system, which is connected to the boiler feedwater tank, deoxygenation tank, heat exchanger, condensate recovery tank, and external steam heat exchanger (which can be achieved through conventional technology), facilitating the control of the boiler feedwater tank, deoxygenation tank, heat exchanger, condensate recovery tank, and external steam heat exchanger.

[0017] Furthermore, in the aforementioned waste heat recovery and deoxygenation system, the control system includes a temperature sensor and a liquid level sensor;

[0018] A temperature sensor is installed on the deaerator to detect the temperature of the deaerator. The temperature sensor is preferably a resistance temperature sensor. A liquid level sensor is also installed on the deaerator to detect the liquid level of the deaerator.

[0019] Furthermore, in the aforementioned waste heat recovery deaeration system, a temperature regulating valve is installed on the pipeline between the external steam input device and the deaeration tank, and a temperature sensor is installed on the pipeline between the temperature regulating valve and the deaeration tank. A level regulating valve and a level sensor connected in series with the level regulating valve are installed on the pipeline between the boiler feedwater tank and the deaeration tank. The level regulating valve automatically adjusts its opening based on the level detected by the level sensor in the deaeration tank, achieving automated system control. The temperature regulating valve automatically adjusts its opening based on the temperature detected by the resistance temperature sensor in the deaeration tank, achieving automated system control.

[0020] Furthermore, in the aforementioned waste heat recovery and deoxygenation system, the control system is an intelligent controller; the intelligent controller is connected to a temperature sensor, a liquid level sensor, a liquid level regulating valve, and a temperature regulating valve, respectively; the intelligent controller automatically adjusts the feed water entering the heat exchanger and the external steam entering the external steam heat exchanger based on the detection data from the temperature sensor and the liquid level sensor, and through the liquid level regulating valve and the temperature regulating valve.

[0021] Furthermore, in the aforementioned waste heat recovery and deoxygenation system, the heat exchanger is a wound tube heat exchanger; the water inlet channels of the heat exchanger are spirally distributed.

[0022] Furthermore, in the aforementioned waste heat recovery deoxygenation system, a deaerator is installed inside the deoxygenation tank. The deaerator is an atmospheric thermal deaerator, which achieves deoxygenation through steam heating. Specifically, the demineralized water is heated to a superheated state by steam heating, and the deoxygenation effect is enhanced through gas-phase spray flash evaporation.

[0023] Furthermore, in the aforementioned waste heat recovery deoxygenation system, the steam inlet at the top of the deoxygenation tank has a built-in insert-type distribution pipe, which allows the condensate after external steam heat exchange to enter and be uniformly heated, reducing equipment vibration.

[0024] Furthermore, in the aforementioned waste heat recovery deaeration system, external steam first passes through an external steam heat exchanger, and then enters through an insert-type distribution pipe built into the steam inlet at the top of the deaeration tank, where it is evenly distributed. The water inlet pipe of the deaeration tank adopts an automatic telescopic pressure spray pipe structure design, which allows for more even distribution of boiler feedwater, greater operational flexibility, and improved deaeration efficiency.

[0025] Furthermore, in the aforementioned waste heat recovery deoxygenation system, the inner wall of the deoxygenation tank is lined with stainless steel plates, that is, the top is provided with a stainless steel lining, which can effectively prevent the oxygen-enriched venting steam from corroding the top of the deoxygenation tank.

[0026] Compared with the prior art, the main advantages of this utility model are as follows:

[0027] (1) By setting up a heat exchanger before the boiler feedwater enters the deaerator and using the vented steam of the deaerator as a heat source to preheat the boiler feedwater, the heat is effectively recovered and utilized, reducing the consumption of external heating steam. Steam consumption can be reduced by 20-25%, and the deaerator temperature can be appropriately increased to further reduce the oxygen partial pressure and improve the deaerator effect.

[0028] (2) The steam in the deaerator tank is vented and cooled into condensate, which is then reused as clean demineralized water. An additional 25-35% of the clean condensate is recovered, realizing the recycling of water resources and further reducing the system operating cost.

[0029] (3) By effectively utilizing the latent heat of the vented steam, direct emissions are reduced, visual pollution is reduced, and the aesthetics of the system are improved. At the same time, the problems of steel structure corrosion and algae growth on concrete structure surface caused by steam condensate are also reduced.

[0030] (4) Select a high-efficiency spiral wound tube heat exchanger to replace the conventional shell and tube heat exchanger according to the characteristics of the system materials. It is small in size, high in efficiency, easy to install and maintain, and improves the practicality and promotion value of the system.

[0031] (5) The system adopts the heat recovery of vented steam, so the working parameters are higher than those of conventional deoxygenation processes. The working pressure is increased by 10~20 kPa and the working temperature of the deoxygenation tank is increased by 5~10℃. The energy saving effect and operating range are better than those of conventional processes.

[0032] (5) The system uses superheated water under deoxygenation pressure as the water inlet and adopts an automatic telescopic pressure spray pipe with spring. The number of spray holes is opened according to the different water inlet volume to spray the demineralized water and flash evaporate it under reduced pressure in the vapor space. This avoids the liquid layer resistance of liquid phase deoxygenation, improves the deoxygenation efficiency, and effectively reduces equipment vibration, which can improve the service life of the equipment. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a waste heat recovery and deoxygenation system.

[0034] The diagram is labeled as follows: 1 - Boiler feedwater tank, 2 - Deaerator tank, 3 - Heat exchanger, 4 - Condensate recovery tank, 5 - External steam heat exchanger, 51 - (Resistor) temperature sensor, 52 - Liquid level sensor, 53 - Liquid level regulating valve, 54 - Temperature regulating valve. Detailed Implementation

[0035] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] In this utility model, some conventional operating equipment, devices and components have been omitted or only briefly described.

[0039] Unless otherwise specified in the examples, the conditions shall be performed according to the standard conditions or the conditions recommended by the manufacturer.

[0040] Example 1:

[0041] A waste heat recovery and deoxygenation system includes an external steam input device, a boiler feedwater tank 1, a deoxygenation tank 2, a heat exchanger 3, a condensate recovery tank 4, and an external steam heat exchanger 5. Furthermore, the system is equipped with a control system, which is connected to the boiler feedwater tank 1, deoxygenation tank 2, heat exchanger 3, condensate recovery tank 4, and external steam heat exchanger 5 respectively, to realize the detection and control of these devices. The control system can be implemented using existing technology.

[0042] An external steam input device is connected to an external steam heat exchanger 5; a spiral-wound tube heat exchanger 3 is installed between the boiler feedwater tank 1 and the deaerator tank 2. The water inlet channels of the spiral-wound tube heat exchanger 3 are spirally distributed, which prolongs the residence time of the water flow in the heat exchanger 3 and improves the heat exchange efficiency.

[0043] The deaerator 2 achieves deaeration through steam heating. The top of the deaerator 2 is equipped with a steam outlet for venting steam, which is connected to the spiral tube heat exchanger 3 via a pipe. The top of the deaerator 2 is also equipped with a steam inlet connected to an external steam heat exchanger 5, which allows external steam to enter the distribution pipe inside the deaerator 2.

[0044] The condensate recovery tank 4 is located at the outlet of the wound tube heat exchanger 3 and is used to collect condensate.

[0045] The control system includes a resistance temperature sensor 51, a level sensor 52, a level regulating valve 53, and a temperature regulating valve 54. The level sensor 52 detects the level in the deaerator tank, and the temperature sensor 51 detects the temperature in the deaerator tank. A level regulating valve 53 is installed on the pipeline between the boiler feedwater tank 1 and the deaerator tank 2. The level regulating valve 53 is connected to the level sensor 52. The level regulating valve 53 automatically adjusts its opening based on the level detected by the level sensor 52 in the deaerator tank 2, thus achieving automated system control. A temperature regulating valve 54 is installed on the pipeline between the external steam input device and the external steam heat exchanger 5. The temperature regulating valve 54 is connected to the temperature sensor 51. The temperature regulating valve 54 automatically adjusts its opening based on the temperature detected by the resistance temperature sensor 51 in the deaerator tank 2, thus achieving automated system control.

[0046] The control system is an intelligent controller; the intelligent controller is connected to temperature sensor 51, liquid level sensor 52, liquid level regulating valve 53 and temperature regulating valve 54 respectively; the intelligent controller automatically adjusts the water supply entering the heat exchanger 3 and the external steam entering the external steam heat exchanger 5 based on the detection data in temperature sensor 51 and liquid level sensor 52, and through liquid level regulating valve 53 and temperature regulating valve 54.

[0047] The inner wall of deaerator 2 is lined with stainless steel plates, which can effectively prevent the oxygen-enriched venting steam from corroding the top of deaerator 2.

[0048] The inlet channel of deaerator 2 adopts an automatic telescopic pressure spray pipe structure design, which enables more uniform distribution of boiler feedwater, provides greater operational flexibility, and improves deaeration efficiency. The steam inlet at the top of deaerator 2 has a built-in insertion distribution pipe for uniform heating of external steam.

[0049] The process of waste heat recovery and deoxygenation using the waste heat boiler deoxygenation system described above includes the following steps:

[0050] 1. Boiler feedwater comes from boiler feedwater tank 1. Before entering deaerator 2, it first enters heat exchanger 3 and external steam heat exchanger 5. The heat source used by heat exchanger 3 is the vented steam from deaerator 2. The feedwater flow rate is controlled by level regulating valve 53 (signal from deaerator level gauge 52).

[0051] 2. The vented steam from deaerator 2 is used as a heat source by boiler feedwater heat exchanger 3 to raise the temperature of the boiler feedwater. At the same time, the vented steam from deaerator 2 is cooled into condensate. This condensate is clean water and can be used as demineralized water in the process system, saving on demineralized water treatment costs.

[0052] 3. After the boiler feedwater temperature rises in the boiler feedwater heat exchanger 3, it enters the external steam heat exchanger 5 for further heating. After passing through the external steam heat exchanger 5, it enters the deaerator 2. The feedwater pressure is 0.15~0.20Mpa and the temperature is 134℃. It is sprayed in the deaerator 2 through the automatic telescopic pressure spray pipe, and some steam is flashed out to improve the deaeration effect.

[0053] 4. The temperature of the deaerator tank 2 is controlled at 106±0.5℃ by external heating steam. The amount of external heating steam entering the external steam heat exchanger 5 is regulated by the temperature regulating valve 54 (the signal comes from the deaerator tank thermometer 51).

[0054] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0055] The background section is provided to generally present the context of this utility model. The work of the currently named inventors, the work to the extent described in this background section, and aspects described in this section that did not constitute prior art at the time of filing are neither expressly nor impliedly acknowledged as prior art to this utility model.

Claims

1. A waste heat recovery and deoxygenation system, characterized in that: The system includes an external steam input device, a boiler feedwater tank (1), a deaerator (2), a heat exchanger (3), a condensate recovery tank (4), and an external steam heat exchanger (5); among which, The external steam input device is connected to the external steam heat exchanger (5); The deaerator (2) is connected to the external steam heat exchanger (5) and the heat exchanger (3) respectively; External steam heat exchanger (5) and heat exchanger (3) are connected; The boiler feedwater tank (1) is connected to the heat exchanger (3); The top of the deaerator (2) is provided with a steam outlet, which is connected to the heat exchanger (3) through a pipe; The condensate recovery tank (4) is located at the outlet of the heat exchanger (3) and is used to collect condensate.

2. The waste heat recovery and deoxygenation system according to claim 1, characterized in that: The system also includes a control system, which is connected to the boiler feedwater tank (1), deaerator (2), heat exchanger (3), condensate recovery tank (4), and external steam heat exchanger (5).

3. The waste heat recovery and deoxygenation system according to claim 2, characterized in that: The control system includes a temperature sensor (51) and a liquid level sensor (52); a temperature sensor (51) is installed on the deoxygenation tank (2) to detect the temperature of the deoxygenation tank (2); a liquid level sensor (52) is also installed on the deoxygenation tank (2) to detect the liquid level of the deoxygenation tank (2).

4. The waste heat recovery and deoxygenation system according to claim 3, characterized in that: A temperature regulating valve (54) is installed on the pipeline between the external steam input device and the deaerator (2), and a temperature sensor (51) is installed on the pipeline between the temperature regulating valve (54) and the deaerator (2); a liquid level regulating valve (53) and a liquid level sensor (52) connected in series with the liquid level regulating valve (53) are installed on the pipeline between the boiler feedwater tank (1) and the deaerator (2).

5. The waste heat recovery and deoxygenation system according to claim 4, characterized in that: The control system is an intelligent controller; the intelligent controller is connected to the temperature sensor (51), the liquid level sensor (52), the liquid level regulating valve (53) and the temperature regulating valve (54) respectively; the intelligent controller automatically adjusts the water supply entering the heat exchanger (3) and the external steam entering the external steam heat exchanger (5) according to the detection data in the temperature sensor (51) and the liquid level sensor (52), and through the liquid level regulating valve (53) and the temperature regulating valve (54).

6. A waste heat recovery and deoxygenation system according to any one of claims 1-5, characterized in that: The heat exchanger (3) is a spiral tube heat exchanger; the water inlet channel of the heat exchanger (3) is spirally distributed.

7. A waste heat recovery and deoxygenation system according to any one of claims 1-5, characterized in that: The deoxygenation tank (2) is equipped with a deoxygenator, which is an atmospheric thermal deoxygenator that achieves deoxygenation through steam heating.

8. A waste heat recovery and deoxygenation system according to any one of claims 1-5, characterized in that: External steam first passes through the external steam heat exchanger (5), and then enters through the built-in insertion distribution pipe of the steam inlet at the top of the deaerator tank (2), and is evenly distributed.

9. A waste heat recovery and deoxygenation system according to any one of claims 1-5, characterized in that: The water inlet pipe of the deaerator (2) is an automatic telescopic pressure spray pipe; the inner wall of the deaerator (2) is a stainless steel lining plate.

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