A device for recovering waste heat from deaerator exhaust steam

Abstract

The utility model discloses a kind of deaerator exhaust steam recovery waste heat utilization device, including deaerator, exhaust steam recovery processing device, desalted water tank, feed water pump, preheating heat exchanger, vice coal economizer, deaerator is connected with the exhaust steam import of exhaust steam recovery processing device;The outlet of desalted water tank is connected with feed water pump, feed water pump is connected with the desalted water import of exhaust steam recovery processing device, the desalted water outlet of exhaust steam recovery processing device is connected with the medium import of preheating heat exchanger by pipeline, the medium outlet of preheating heat exchanger is connected with the medium import of vice coal economizer, the medium outlet of vice coal economizer is connected with the water inlet of deaerator by pipeline;The condensate outlet of exhaust steam recovery processing device is connected with the import of desalted water tank. Advantage: deaerator exhaust steam and desalted water heat exchange, desalted water is then into preheating heat exchanger, preheat boiler feed water before entering boiler, reduce heat energy consumption to a certain extent.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization, specifically to a device for recovering waste heat from deaerator exhaust steam. Background Technology

[0002] During the dry quenching process of coking, in order to ensure the quality of the feedwater in the dry quenching boiler and avoid oxygen corrosion of pipelines and boiler tubes, it is necessary to deoxygenate the boiler feedwater. The dry quenching process mainly uses thermal deoxygenation, supplemented by chemical deoxygenation. That is, a deaerator is used to heat the feedwater (also called demineralized water) to the saturation temperature at the corresponding pressure by inputting steam. The water vapor pressure at the steam-water interface is the same as the external pressure, and the partial pressure of other gases (including oxygen) is zero. That is, the gases dissolved in the water cannot be dissolved in the water and are removed. At the same time, deoxygenating agents such as hydrazine are added to combine with the residual dissolved oxygen in the feedwater.

[0003] Currently, the industry mostly discharges the exhaust steam after dry quenching and deoxygenation directly. However, the heat from the steam and the water vapor it carries are wasted. It is necessary to utilize the waste heat and recover the moisture. Utility Model Content

[0004] The purpose of this invention is to provide a device for recovering waste heat from deaerator exhaust steam.

[0005] This utility model is implemented by the following technical solution: A waste heat recovery and utilization device for deaerator exhaust steam includes a deaerator, a waste steam recovery and treatment device, a demineralized water tank, a feed water pump, a preheating heat exchanger, and a secondary economizer. The top exhaust steam outlet of the deaerator is connected to the exhaust steam inlet of the waste steam recovery and treatment device. The outlet of the demineralized water tank is connected to the inlet of the feed water pump, the outlet of the feed water pump is connected to the demineralized water inlet of the waste steam recovery treatment device, the demineralized water outlet of the waste steam recovery treatment device is connected to the medium inlet of the preheating heat exchanger through a pipeline, the medium outlet of the preheating heat exchanger is connected to the medium inlet of the auxiliary economizer, and the medium outlet of the auxiliary economizer is connected to the water inlet of the deaerator through a pipeline. The condensate outlet of the waste steam recovery treatment device is connected to the inlet of the demineralized water tank.

[0006] Preferably, the waste steam recovery and treatment device includes a cylindrical shell, with a waste steam inlet and a condensate outlet on one side of the shell, a demineralized water inlet and a demineralized water outlet on both sides of the top of the shell, and a waste steam discharge port at the center of the top of the shell; The shell is equipped with spiral heat exchange tubes at the top and bottom, respectively, and a trumpet-shaped exhaust steam diffuser. One end of the heat exchange tube is connected to the demineralized water inlet, and the other end of the heat exchange tube extends upward from the bottom center of the heat exchange tube and is connected to the demineralized water outlet.

[0007] Preferably, the exhaust steam diffuser includes an inverted trumpet-shaped diffuser head, and the top of the diffuser head is provided with multiple rings of vent holes around a central matrix. Each ring of the vent hole group consists of multiple vent holes, and the diameter of the vent holes in the multiple rings of the vent hole group gradually increases from the center to the periphery. The bottom of the diffuser head is connected to a cylinder, and one side of the cylinder is connected to the exhaust steam outlet.

[0008] Preferably, the heat exchange inlet and outlet of the preheating heat exchanger are connected in series to the boiler feedwater pipeline before entering the boiler.

[0009] Preferably, the heat exchange inlet and outlet of the auxiliary economizer are connected in series on the boiler flue after exiting the boiler.

[0010] The advantages of this invention are as follows: The exhaust steam from the deaerator is discharged into the exhaust steam recovery and treatment device, where it rises and disperses through the diffuser head, allowing for more uniform heat exchange with the heat exchange tubes. The demineralized water in the demineralized water tank is extracted to the heat exchange tubes, heated by the high-temperature exhaust steam, and then enters the preheating heat exchanger to preheat the boiler feedwater before it enters the boiler, reducing heat consumption to a certain extent. Afterward, it enters the auxiliary economizer for heat exchange, cooling the flue gas. The heated demineralized water returns to the deaerator, mixing with the demineralized water in the deaerator water tank, increasing the temperature of the demineralized water in the deaerator water tank, which is beneficial for high-temperature deoxygenation within the deaerator. Furthermore, the moisture in the exhaust steam condenses and drips to the bottom of the shell, flowing into the demineralized water tank for recovery, ensuring that neither waste heat nor moisture is wasted. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0013] Figure 2 This is a schematic diagram of the structure of the waste steam recovery and treatment device of this utility model.

[0014] Figure 3 This is a top view of the diffuser head structure of this utility model.

[0015] In the diagram: 1. Deaerator, 2. Waste steam recovery and treatment device, 2.1. Shell, 2.2. Heat exchange tube, 2.3. Waste steam diffuser, 2.3.1. Vent hole group, 2.3.2. Vent hole, 2.3.2.1. Cylinder, 2.3.3. Demineralized water tank, 3. Feed water pump, 4. Preheating heat exchanger, 5. Subsidiary economizer. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] like Figure 1 , Figure 2 , Figure 3 As shown, a waste heat recovery device for deaerator exhaust steam includes a deaerator 1, a waste steam recovery and treatment device 2, a demineralized water tank 3, a feed water pump 4, a preheating heat exchanger 5, and a secondary economizer 6. The top exhaust steam outlet of the deaerator 1 is connected to the exhaust steam inlet of the waste steam recovery and treatment device 2; the exhaust steam of the deaerator 1 is discharged into the waste steam recovery and treatment device 2.

[0018] The outlet of the demineralized water tank 3 is connected to the inlet of the feed water pump 4. The outlet of the feed water pump 4 is connected to the demineralized water inlet of the waste steam recovery treatment device 2. The demineralized water outlet of the waste steam recovery treatment device 2 is connected to the medium inlet of the preheating heat exchanger 5 through a pipeline. The heat exchange inlet and outlet of the preheating heat exchanger 5 are respectively connected in series on the boiler feed water pipeline before entering the boiler. The medium outlet of the preheating heat exchanger 5 is connected to the medium inlet of the auxiliary economizer 6. The medium outlet of the auxiliary economizer 6 is connected to the water inlet of the deaerator 1 through a pipeline. The heat exchange inlet and outlet of the auxiliary economizer 6 are respectively connected in series on the boiler flue after exiting the boiler. The demineralized water in the demineralized water tank 3 is drawn out by the feed water pump 4 and enters the waste steam recovery treatment device 2, where it exchanges heat with the waste steam. The demineralized water is heated and then enters the preheating heat exchanger 5 to preheat the boiler feedwater before it enters the boiler, which reduces heat energy consumption to a certain extent. After that, it enters the auxiliary economizer 6 for heat exchange, which cools the flue gas. After being heated, the demineralized water returns to the deaerator 1 and mixes with the demineralized water in the deaerator water tank, raising the temperature of the demineralized water in the deaerator water tank, which is conducive to high-temperature deoxygenation in the deaerator.

[0019] The condensate outlet of the waste steam recovery and treatment device 2 is connected to the inlet of the demineralized water tank 3. The moisture in the waste steam is condensed by heat exchange with the low-temperature demineralized water, and the condensate flows from the waste steam recovery and treatment device 2 to the demineralized water tank 3 to complete the recovery.

[0020] The waste steam recovery and treatment device 2 includes a cylindrical shell 2.1. A waste steam inlet and a condensate outlet are provided on one side of the shell 2.1. A demineralized water inlet and a demineralized water outlet are provided on both sides of the top of the shell 2.1. A waste steam discharge port is provided at the center of the top of the shell 2.1. The shell 2.1 has spiral heat exchange tubes 2.2 and a trumpet-shaped exhaust steam diffuser 2.3 installed at the top and bottom respectively. One end of the heat exchange tube 2.2 is connected to the demineralized water inlet, and the other end of the heat exchange tube 2.2 extends upward from the bottom center of the heat exchange tube 2.2 and is connected to the demineralized water outlet.

[0021] High-temperature exhaust steam is dispersed and rises within the shell 2.1 through the exhaust steam diffuser 2.3, passing relatively evenly through and contacting the heat exchange tube 2.2. The exhaust steam is discharged from the exhaust steam outlet, while the heat exchange tube 2.2 is filled with relatively low-temperature demineralized water. The moisture in the exhaust steam condenses and drips to the bottom of the shell 2.1, flowing out from the condensate outlet.

[0022] The exhaust steam diffuser 2.3 includes an inverted trumpet-shaped diffuser head 2.3.1. The top of the diffuser head 2.3.1 is provided with multiple rings of vent holes 2.3.2 around a central matrix. Each ring of vent holes 2.3.2 consists of multiple vent holes 2.3.2.1. The diameter of the vent holes 2.3.2.1 in the multiple rings of vent holes 2.3.2.2 gradually increases from the center to the periphery. The bottom of the diffuser head 2.3.1 is connected to the cylinder 2.3.3, and one side of the cylinder 2.3.3 is connected to the exhaust steam outlet.

[0023] The exhaust steam first enters the cylinder 2.3.3, rises and passes through the diffuser head 2.3.1, and is dispersed by the multi-ring vent group 2.3.2. It is discharged from multiple vent holes 2.3.2.1. The exhaust steam volume is large at the center, so the diameter of the vent holes 2.3.2.1 in the vent group 2.3.2 located at the center is smaller, and the discharge volume is relatively reduced, causing the exhaust steam to move to the surrounding area. At this time, the exhaust steam also gradually decreases to the surrounding area. Then, it is discharged from the vent holes 2.3.2.1 of the vent group 2.3.2 from the center to the outer edge, and the diameter gradually increases, allowing the exhaust steam to gradually increase from the center to the outer edge, dispersing the exhaust steam upwards and discharging it relatively evenly.

[0024] Condensate flows to the diffuser head 2.3.1 of the exhaust steam diffuser 2.3, and can drip through the cylinder 2.3.3 to the bottom of the shell 2.1.

[0025] Working principle: When this utility model is in use, the exhaust steam from the deaerator 1 is discharged into the exhaust steam recovery and treatment device 2. It first enters the cylinder 2.3.3, rises and passes through the diffuser head 2.3.1, is dispersed by the multi-ring vent group 2.3.2, and is discharged from multiple vent holes 2.3.2.1, making relatively uniform contact with the heat exchange tube 2.2, and then is discharged from the exhaust steam discharge port.

[0026] The demineralized water in the demineralized water tank 3 is drawn out by the feed water pump 4 and enters the heat exchange tube 2.2 in the exhaust steam recovery treatment device 2. It exchanges heat with the low-temperature demineralized water in the heat exchange tube 2.2. The spiral heat exchange tube 2.2 extends the contact time and increases the contact area, so the demineralized water is heated. Then it enters the preheating heat exchanger 5 to preheat the boiler feedwater before it enters the boiler, which reduces the heat energy consumption to a certain extent. Then it enters the auxiliary economizer 6 for heat exchange, which cools the flue gas. After being heated, the demineralized water returns to the deaerator 1 and mixes with the demineralized water in the deaerator water tank, which increases the temperature of the demineralized water in the deaerator water tank and facilitates high-temperature deoxygenation in the deaerator.

[0027] The moisture in the exhaust steam condenses and drips to the bottom of the shell 2.1, and flows from the condensate outlet to the demineralized water tank 3 for recycling.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for recovering waste heat from deaerator exhaust steam, characterized in that, It includes a deaerator, a waste steam recovery and treatment device, a demineralized water tank, a feed water pump, a preheating heat exchanger, and a secondary economizer. The top waste steam outlet of the deaerator is connected to the waste steam inlet of the waste steam recovery and treatment device. The outlet of the demineralized water tank is connected to the inlet of the feed water pump, the outlet of the feed water pump is connected to the demineralized water inlet of the waste steam recovery treatment device, the demineralized water outlet of the waste steam recovery treatment device is connected to the medium inlet of the preheating heat exchanger through a pipeline, the medium outlet of the preheating heat exchanger is connected to the medium inlet of the auxiliary economizer, and the medium outlet of the auxiliary economizer is connected to the water inlet of the deaerator through a pipeline. The condensate outlet of the waste steam recovery treatment device is connected to the inlet of the demineralized water tank.

2. The waste heat recovery device for deaerator exhaust steam according to claim 1, characterized in that: The waste steam recovery and treatment device includes a cylindrical shell, with a waste steam inlet and a condensate outlet on one side of the shell, a demineralized water inlet and a demineralized water outlet on both sides of the top of the shell, and a waste steam discharge port at the center of the top of the shell. The shell is equipped with spiral heat exchange tubes at the top and bottom, respectively, and a trumpet-shaped exhaust steam diffuser. One end of the heat exchange tube is connected to the demineralized water inlet, and the other end of the heat exchange tube extends upward from the bottom center of the heat exchange tube and is connected to the demineralized water outlet.

3. The waste heat recovery device for deaerator exhaust steam according to claim 2, characterized in that: The exhaust steam diffuser includes an inverted trumpet-shaped diffuser head. The top of the diffuser head is provided with multiple rings of vent holes around a central matrix. Each ring of the vent hole group consists of multiple vent holes, and the diameter of the vent holes in the multiple rings of the vent hole group gradually increases from the center to the periphery. The bottom of the diffuser head is connected to a cylinder, and one side of the cylinder is connected to the exhaust steam outlet.

4. The waste heat recovery device for deaerator exhaust steam according to claim 1, characterized in that: The heat exchange inlet and outlet of the preheating heat exchanger are connected in series to the boiler feedwater pipeline before entering the boiler.

5. The waste heat recovery device for deaerator exhaust steam according to claim 1, characterized in that: The heat exchange inlet and outlet of the auxiliary economizer are connected in series on the boiler flue after the boiler.

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