A boiler secondary air preheating device

Abstract

The utility model discloses a boiler secondary air preheating device, include: at least one oxygen remover, at least one first pipeline, at least one three -way joint, at least one first switch valve, at least one second pipeline group, at least one second switch valve and warm air blower unit, the oxygen remover is equipped with oxygen -removing steam export, one end of first pipeline is linked together with corresponding oxygen -removing steam export of oxygen remover, the three -way joint is equipped with the first mouth, the second mouth and the third mouth of intercommunication, the first mouth is linked together with the other end of corresponding first pipeline, first switch valve sets up on first pipeline, second pipeline group is equipped with the air inlet end and the air outlet end, it can effectively recycle and utilize the heat of oxygen remover oxygen -removing steam, realizes the preheating to boiler secondary air, improves the combustion efficiency, reduces the energy consumption, and has the characteristics of simple structure, low cost, reliable operation simultaneously.

Description

Technical Field

[0001] This utility model relates to a boiler secondary air preheating device, belonging to the field of waste heat recovery technology. Background Technology

[0002] Currently, during boiler operation, combustion requires a large amount of secondary air to maintain the combustion process. Especially during winter operation, the cold air drawn in from the outside is at a low temperature and directly entering the boiler will affect the combustion efficiency.

[0003] Meanwhile, as an important piece of equipment in industrial boiler systems, deaerators generate a large amount of exhaust steam during operation. These steams are usually around 150-170℃ and have high thermal energy value, but they are often directly discharged into the atmosphere, resulting in energy waste.

[0004] After searching the existing technology, it was found that Chinese patent CN115183223B discloses an energy-saving method and system for deep utilization of low-temperature waste heat in the entire system of a cogeneration plant. In this patent, the exhaust steam from the deaerator is introduced into the heater of the secondary air fan for heat exchange, thereby increasing the temperature of the hot primary air and hot secondary air. However, it was found during use that the temperature of the steam discharged from the deaerator is unstable during the start-up phase. Directly entering the mixing heat exchanger can easily affect the heat exchange effect and the stability of equipment operation, thus affecting the overall thermal efficiency. In addition, in actual operation, there are also situations where the deaerator is running normally but the fan is shut down, such as during equipment maintenance or malfunction. At this time, the deaerator continues to discharge steam, which can easily accumulate in the heat exchanger or fan, causing equipment damage. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a boiler secondary air preheating device that can effectively recover and utilize the heat of the deaerator exhaust steam to preheat the boiler secondary air, improve combustion efficiency, reduce energy consumption, and has the characteristics of simple structure, low cost and reliable operation.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is: a boiler secondary air preheating device, comprising: At least one deaerator, the deaerator being provided with a deaerated steam outlet; At least one first pipeline, one end of which is connected to the deoxygenated steam outlet of the corresponding deaerator; At least one tee connector, the tee connector having a first port, a second port and a third port that are interconnected, the first port being connected to the other end of the corresponding first pipeline; At least one first switching valve is provided on the corresponding first pipeline; At least one second pipeline assembly, the second pipeline assembly having an air inlet and an air outlet, the air inlet being connected to the second port of the tee connector; At least one second switching valve is provided on a corresponding second pipeline group; At least one third conduit, one end of which is connected to the third port of the corresponding tee fitting; At least one third switching valve is provided on a corresponding third pipeline; A heating air handling unit, the heating air handling unit includes a heat exchanger, the heat exchanger is provided with a heat exchange steam inlet, a heat exchange outlet, a secondary air inlet and a secondary air outlet, the heat exchange steam inlet of the heat exchanger is connected to the air outlet of the second pipeline group, and the secondary air inlet is connected to the secondary air channel of the boiler; The steam from the deaerator is suitable for being transported to the heat exchange steam inlet of the heat exchanger through the second pipeline group, and the secondary air entering the boiler is heated by the heat exchanger.

[0007] Furthermore, the boiler secondary air preheating device also includes a temperature sensor and a controller. The temperature sensor is installed on the first pipeline and is adapted to collect the temperature of the steam in the first pipeline. The controller is connected to the second switching valve, the third switching valve and the temperature sensor respectively, and the controller is adapted to drive the second switching valve and the third switching valve to operate according to the temperature feedback from the temperature sensor.

[0008] Furthermore, there are two deaerators, which are connected in parallel. The heating unit has three sets.

[0009] Furthermore, each of the aforementioned heating units is equipped with a pair of parallel heating fans.

[0010] Furthermore, the second pipeline assembly includes: Two steam inlet pipes are respectively connected to the second port of the tee connector that is connected to the corresponding deaerator; A connecting pipe is provided, which is connected to the two steam inlet pipes; The system comprises a first steam outlet pipe, a second steam outlet pipe, and a third steam outlet pipe. One end of each of the first, second, and third steam outlet pipes is connected to the connecting pipe, and the other end is connected to the heat exchange steam inlet of the corresponding heat exchanger of the heating unit.

[0011] Furthermore, the boiler secondary air preheating device also includes an air intake control device, which includes: The first control valve is installed on the first steam outlet pipe; The second control valve is installed on the second steam outlet pipe; The third control valve is installed on the third steam outlet pipe.

[0012] Furthermore, the boiler secondary air preheating device also includes at least one condensate drain assembly, the condensate drain assembly comprising: A hydrophobic expansion container is provided with an expansion container inlet, a gas outlet and a liquid outlet, wherein the expansion container inlet is connected to the heat exchange outlet of the heat exchanger. A hydrophobic header is connected to the liquid outlet of the hydrophobic expansion container.

[0013] By adopting the above technical solution, this utility model has the following beneficial effects: In this invention, during operation, the steam discharged from the deaerator through the deaerated steam outlet is transported to the tee connector via the first pipeline. When heating of the secondary air entering the boiler is not required, or when the steam temperature discharged during the deaerator startup phase is unstable, the second switching valve is closed and the third switching valve is opened, allowing the steam to be directly discharged to the external atmosphere through the first to third ports of the tee connector. This prevents unstable-temperature steam from entering the heat exchanger and affecting the heat exchange effect and equipment operational stability. When heating of the secondary air entering the boiler is required, or when the steam temperature discharged from the deaerator stabilizes, the second switching valve is opened and the third switching valve is closed. Steam with a stable temperature is transported through the first to second ports of the tee connector to the heat exchange steam inlet of the heat exchanger via the second pipeline group. In the heat exchanger, it exchanges heat with the secondary air entering from the secondary air inlet. The heated secondary air is then transported to the boiler through the secondary air outlet, thus achieving preheating of the secondary air entering the boiler, improving combustion efficiency, and reducing energy consumption.

[0014] In summary, this invention effectively solves the problems of unstable steam temperature during the deaerator start-up phase and steam accumulation in the deaerator during boiler shutdown. At the same time, it fully recovers and utilizes the heat of the deaerator exhaust steam, achieving efficient preheating of the boiler's secondary air, significantly improving combustion efficiency, and reducing energy consumption. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the boiler secondary air preheating device in Example 1; Figure 2 This is a schematic diagram of the boiler secondary air preheating device in Example 2. Detailed Implementation

[0016] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Example 1: As Figure 1 As shown, a boiler secondary air preheating device includes: Two deaerators 1, each deaerator 1 is equipped with a deaerated steam outlet; Two first pipelines 2, one end of which is connected to the deoxygenated steam outlet of the corresponding deaerator 1; Two T-connectors, each T-connector having a first port, a second port and a third port that are interconnected. The first port is connected to the other end of the corresponding first pipe 2, and the third port is suitable for connecting to the outside. Two first switching valves 3 are installed on corresponding first pipelines 2; The second pipeline group 4 is provided with an air inlet and an air outlet. The air inlet is connected to the second port of the corresponding tee connector. Two second switching valves 5 are installed on the corresponding second pipeline group 4; Two third pipes 8, one end of which is connected to the third port of the corresponding tee fitting; Two third switching valves are installed on the third pipeline 8; Three warm air units 7, each warm air unit 7 includes a pair of warm air blowers, each warm air blower has a heat exchanger, the heat exchanger is provided with a heat exchange steam inlet, a heat exchange outlet, a secondary air inlet and a secondary air outlet, the heat exchange steam inlet of the heat exchanger is connected to the air outlet of the second pipeline group 4, and the secondary air inlet and secondary air outlet are connected to the secondary air passage of the boiler. The steam from the deaerator 1 is suitable for being transported to the heat exchange steam inlet of the heat exchanger through the second pipeline group 4, and the secondary air entering the boiler is heated by the heat exchanger.

[0018] In this embodiment, as Figure 1As shown, during operation, the steam discharged from the deaerator 1 through the deaerated steam outlet is transported to the tee joint via the first pipeline 2. When heating of the secondary air entering the boiler is not required, or when the steam temperature discharged from the deaerator 1 during startup is unstable, the second switching valve 5 is closed and the third switching valve is opened, allowing the unstable steam to be directly discharged to the outside atmosphere through the first to third ports of the tee joint. When heating of the secondary air entering the boiler is required, or when the steam temperature discharged from the deaerator 1 is stable, the second switching valve 5 is opened and the third switching valve is closed. The steam is transported through the first to second ports of the tee joint and through the second pipeline group 4 to the heat exchange steam inlet of the heat exchanger. In the heat exchanger, it exchanges heat with the secondary air entering from the secondary air inlet. The heated secondary air is then transported to the secondary air passage of the boiler through the secondary air outlet, thus achieving preheating of the secondary air entering the boiler.

[0019] Specifically, when the ambient temperature is high or the boiler load is low, it is not necessary to heat the secondary air entering the boiler, or if only the deaerator 1 is used for independent operation, the boiler's secondary air is not required. The first switching valve 3 is a manual main valve and is kept in the normally open state.

[0020] Specifically, the boiler secondary air preheating device also includes a temperature sensor and a controller. The temperature sensor is installed on the first pipeline 2 and is suitable for collecting the temperature of the steam in the first pipeline 2. The controller is connected to the second switching valve 5, the third switching valve and the temperature sensor respectively. The controller is adapted to drive the second switching valve 5 and the third switching valve according to the temperature feedback from the temperature sensor.

[0021] In this embodiment, the temperature sensor is a thermocouple temperature sensor, and the controller is a PLC controller. When the temperature received by the controller is lower than the preset temperature threshold, the PLC controller controls the third switching valve to open and the second switching valve 5 to close, so that the steam of the deaerator 1 is discharged to the outside through the third port of the three-way connector.

[0022] In some embodiments, the temperature sensor may also be a thermistor temperature sensor or an infrared temperature sensor, and the controller may also be a microcontroller controller or an industrial computer controller.

[0023] Specifically, such as Figure 1 As shown, there are two deaerators 1, which are connected in parallel. The heater unit 7 has three sets.

[0024] Specifically, such as Figure 1 As shown, each group of heating units 7 is equipped with a pair of parallel heating units.

[0025] In this embodiment, as Figure 1As shown, two deaerators 1 are connected to their respective first pipelines 2 via their deaerated steam outlets. The two deaerators 1, arranged in parallel, can simultaneously provide steam heat to the heat exchanger, thereby meeting the heating needs of multiple sets of warm air units 7. Each boiler is equipped with a corresponding warm air unit 7 for heating the secondary air entering the corresponding boiler.

[0026] Specifically, such as Figure 1 As shown, the second pipeline group 4 includes: Two steam inlet pipes 41 are connected to the second port of the tee connector that is connected to the corresponding deaerator 1; Connecting pipe 42 is connected to two steam inlet pipes 41; The first steam outlet pipe 43, the second steam outlet pipe 44, and the third steam outlet pipe 45 are connected at one end to the connecting pipe 42, and at the other end to the heat exchange steam inlet of the heat exchanger of the corresponding heating unit 7.

[0027] In this embodiment, as Figure 1 As shown, the two steam inlet pipes 41 merge through the connecting pipe 42 to form a steam collection channel. The connecting pipe 42 distributes the steam from the two deaerators 1 to each heating unit 7, thereby realizing the centralized collection and unified distribution of steam.

[0028] Specifically, such as Figure 1 As shown, the boiler secondary air preheating device also includes an air intake control device, which includes: The first control valve is installed on the first steam outlet pipe 43; The second control valve is installed on the second steam outlet pipe 44; The third control valve is installed on the third steam outlet pipe 45.

[0029] In this embodiment, as Figure 1 As shown, the first steam outlet pipe 43, the second steam outlet pipe 44, and the third steam outlet pipe 45 are each equipped with a corresponding boiler. The operator can control the corresponding pipe to receive steam as needed. For example, when the boilers corresponding to the first steam outlet pipe 43 and the second steam outlet pipe 44 do not need to heat the secondary air entering the boiler, the first steam outlet pipe 43 can be closed by the first control valve, the second steam outlet pipe 44 can be closed by the second control valve, and the third control valve can be kept open to allow steam to enter only the third steam outlet pipe 45.

[0030] Example 2: This example is basically the same as Example 1, except that: Specifically, such as Figure 2 As shown, the boiler secondary air preheating device also includes a condensate drain assembly, which includes: The hydrophobic expansion container 9 is provided with an expansion container inlet, a gas outlet and a liquid outlet. The expansion container inlet is connected to the heat exchange outlet of the heat exchanger. The drainage header 11 is connected to the liquid outlet of the drainage expansion container 9.

[0031] In this embodiment, as Figure 2 As shown, the heat exchange outlet of the heat exchanger is also connected to the expansion inlet of the condensate expansion vessel 9. The condensate expansion vessel 9 separates the moisture from the steam. The separated steam is discharged to the atmosphere, and the separated water is discharged to the condensate header 11, which then flows to the condensate tank. This prevents condensate from accumulating in the pipes.

[0032] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A boiler secondary air preheating device, characterized in that, include: At least one deaerator (1), said deaerator (1) having a deaerated steam outlet; At least one first pipeline (2), one end of which is connected to the deoxygenated steam outlet of the corresponding deaerator (1); At least one tee connector, the tee connector having a first port, a second port and a third port that are interconnected, the first port being connected to the other end of the corresponding first pipe (2); At least one first switching valve (3) is provided on the corresponding first pipeline (2); At least one second pipeline group (4) is provided with an air inlet and an air outlet, and the air inlet is connected to the second port of the three-way connector; At least one second switching valve (5) is provided on the corresponding second pipeline group (4); At least one third pipe (8), one end of which is connected to the third port of the corresponding tee connector; At least one third switching valve is provided on the corresponding third pipeline (8); The heating unit (7) includes a heater, which has a heat exchanger. The heat exchanger is provided with a heat exchange steam inlet, a heat exchange outlet, a secondary air inlet and a secondary air outlet. The heat exchange steam inlet of the heat exchanger is connected to the air outlet of the second pipeline group (4), and the secondary air inlet is connected to the secondary air channel of the boiler. The steam from the deaerator (1) is suitable for being transported to the heat exchange steam inlet of the heat exchanger through the second pipeline group (4), and the secondary air entering the boiler is heated by the heat exchanger.

2. The boiler secondary air preheating device according to claim 1, characterized in that, It also includes a temperature sensor and a controller, wherein the temperature sensor is installed on the first pipeline (2) and is adapted to collect the temperature of the steam in the first pipeline (2); The controller is connected to the second switching valve (5), the third switching valve and the temperature sensor respectively. The controller is adapted to drive the second switching valve (5) and the third switching valve to operate according to the temperature feedback from the temperature sensor.

3. The boiler secondary air preheating device according to claim 1, characterized in that, Two deaerators (1) are provided, and the two deaerators (1) are connected in parallel; The heating unit (7) has three sets.

4. The boiler secondary air preheating device according to claim 3, characterized in that, Each of the aforementioned heating units (7) is equipped with a pair of parallel heating units.

5. The boiler secondary air preheating device according to claim 3, characterized in that, The second pipeline assembly (4) includes: Two steam inlet pipes (41) are connected to the second port of the tee connector that is connected to the corresponding deaerator (1); Connecting pipe (42), which is connected to the two steam inlet pipes (41); The first steam outlet pipe (43), the second steam outlet pipe (44), and the third steam outlet pipe (45) are connected at one end to the connecting pipe (42) and at the other end to the heat exchange steam inlet of the heat exchanger of the corresponding heating unit (7).

6. The boiler secondary air preheating device according to claim 5, characterized in that, It also includes an intake control device, which includes: The first control valve is installed on the first steam outlet pipe (43); The second control valve is installed on the second steam outlet pipe (44); The third control valve is installed on the third steam outlet pipe (45).

7. The boiler secondary air preheating device according to claim 1, characterized in that, It also includes at least one hydrophobic component, the hydrophobic component comprising: A hydrophobic expansion container (9) is provided with an expansion container inlet, a gas outlet and a liquid outlet, and the expansion container inlet is connected to the heat exchange outlet of the heat exchanger; A hydrophobic header (11) is connected to the liquid outlet of the hydrophobic expansion container (9).

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