Wet desulphurization flue gas waste heat recycling device

Abstract

The utility model discloses a wet desulphurization flue gas waste heat recycling device which comprises a desulfurizing tower, and the flue gas discharge end of the desulfurizing tower is communicated with a spraying waste heat recycling tower. The spraying waste heat recovery tower comprises a tower body, the lower end of the interior of the tower body is provided with a transverse air injection disc communicated with the flue gas discharge end of the desulfurization tower, the upper part of the air injection disc is provided with a plurality of nozzle units, and the upper part of the interior of the tower body is provided with a plurality of layers of spraying discs from top to bottom; the spraying disc located on the lower portion can spray out large water drops through the spraying heads with the large diameter, the dense large water drops can rapidly absorb the initial smoke and high-temperature heat, then when the smoke rises more upwards, the temperature of the smoke can be gradually reduced due to heat exchange, and therefore the spraying heads with the small diameter can spray out water drops with the smaller particle size at the moment, and the smoke can be sprayed out through the spraying heads with the large diameter. And therefore, the coverage density of the water drops is higher, and the contact area between the water drops and the flue gas is larger, so that the absorption efficiency of the flue gas waste heat is deeply improved, and the heat energy is recycled as far as possible.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection, and particularly relates to a device for recovering and utilizing the waste heat of wet desulfurization flue gas. Background Technique

[0002] In the process of thermoelectric production, as an important means to reduce the emission of atmospheric pollutants, the traditional wet desulfurization technology is widely used in flue gas purification. However, the low-temperature flue gas (usually in the range of 50 - 150 °C) discharged after the treatment of this technology still contains a large amount of heat energy resources. If these heat energies are directly discharged into the atmosphere, it will not only cause great waste of energy, but also exacerbate the thermal pollution of the environment. With the increasing global attention to energy conservation, emission reduction and efficient utilization of energy, developing an efficient and reliable flue gas waste heat recovery technology is of great significance for improving the comprehensive energy efficiency of power plants, reducing energy consumption and reducing greenhouse gas emissions. Content of the Utility Model

[0003] The purpose of this part is to outline some aspects of the implementation mode of the utility model and briefly introduce some preferred implementation modes. In this part, as well as in the abstract of the specification and the name of the utility model of this application, some simplifications or omissions may be made to avoid obscuring the purpose of this part, the abstract of the specification and the name of the utility model, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0004] Therefore, the purpose of the utility model is to provide a device for recovering and utilizing the waste heat of wet desulfurization flue gas, so as to solve the problems that the heat energy generated after the treatment of the traditional wet desulfurization technology cannot be utilized and the thermal pollution of the environment is exacerbated as mentioned in the above background technique.

[0005] To achieve the above purpose, the utility model provides the following technical solution: A device for recovering and utilizing the waste heat of wet desulfurization flue gas, which includes a desulfurization tower, and the flue gas discharge end of the desulfurization tower is communicated with a spray waste heat recovery tower;

[0006] The spray waste heat recovery tower includes a tower body. The lower end inside the tower body has a horizontally arranged jet disk connected to the flue gas discharge end of the desulfurization tower, and there are several spray nozzle units above the jet disk. Multiple spray trays are arranged from top to bottom above the inside of the tower body;

[0007] The absorption heat pump unit includes a heat network return water pipe for initially supplying the pump unit. The heat network return water pipe has a water inlet unit and a water outlet unit. The absorption heat pump unit transports the water introduced from the heat network return water pipe to the spray trays in each layer area through a set of water control pipes. The hot water after heat exchange in the spray waste heat recovery tower is connected to the heat treatment unit of the absorption heat pump unit through a set of return pipes;

[0008] Among them, the flue gas after waste heat recovery in the spray waste heat recovery tower is discharged through a chimney arranged outside.

[0009] As a preferred embodiment of the wet flue gas waste heat recovery and utilization device of the present utility model, the output end of the desulfurization tower is provided with a boiler flue gas pipeline connected to the boiler, and the output end of the desulfurization tower is provided with an exhaust pipe connected to the jet tray, and corresponding control valves are also arranged on the boiler flue gas pipeline and the exhaust pipe.

[0010] As a preferred embodiment of the wet flue gas waste heat recovery and utilization device of the present utility model, a sump communicating with the reflux pipe is arranged at the bottom of the inner cabin of the tower body.

[0011] As a preferred embodiment of the wet flue gas waste heat recovery and utilization device of the present utility model, the spray tray is composed of pipelines of multiple inner and outer loops, connecting braces are fixed between the inner and outer pipelines, and spray heads evenly distributed and communicating with the bottom of the pipelines are also arranged at the bottom of the spray tray;

[0012] Among them, the diameters of the spray nozzles at the bottom of the lowermost spray tray gradually decrease upwards, and the number of layers of the spray tray is not less than three.

[0013] As a preferred embodiment of the wet flue gas waste heat recovery and utilization device of the present utility model, pressure relief valves are evenly distributed on the top of the jet tray.

[0014] As a preferred embodiment of the wet flue gas waste heat recovery and utilization device of the present utility model, the water control pipe group includes a water delivery main pipe with one end connected to the absorption heat pump unit, a diaphragm metering pump arranged on the water delivery main pipe, a plurality of branch water pipes communicated with the pipeline of the water delivery main pipe, the other end of each branch water pipe is connected to the corresponding spray tray, and electromagnetic flow valves are also arranged on the branch water pipes.

[0015] As a preferred embodiment of the wet flue gas waste heat recovery and utilization device of the present utility model, an exhaust pipe communicating with the chimney is also arranged at the top of the tower body.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows: for this wet flue gas waste heat recovery and utilization device, through the integration of spray waste heat recovery and heat pump boosting technology, the efficient recovery and utilization of flue gas waste heat are realized, the comprehensive energy efficiency of the power plant is significantly improved, and the energy consumption is reduced; moreover, while reducing the direct emission of flue gas waste heat and reducing environmental heat pollution, the carbon emission of the power plant is also reduced. This waste heat recovery system can flexibly configure waste heat utilization schemes according to the actual needs of the power plant, so as to realize the cascade utilization of energy and the maximum value excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall process structure of the present utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the spray waste heat recovery tower of the present utility model;

[0019] Figure 3 This is a schematic diagram of the upward view of the spray tray of the present utility model;

[0020] Figure 4 This is a schematic diagram of the upper part of the air jet tray of the present utility model.

[0021] In the figure: 100, desulfurization tower; 110, boiler flue gas pipeline; 120, exhaust pipe; 200, spray waste heat recovery tower; 210, tower body; 220, spray tray; 221, spray head; 222, connecting brace; 230, air jet tray; 231, pressure relief valve; 240, sump; 250, exhaust pipe; 300, absorption heat pump unit; 310, heat network return water pipe; 320, water control pipe group; 321, main water delivery pipe; 322, diaphragm metering pump; 323, branch water pipe; 324, electromagnetic flow valve; 330, return pipe; 400, chimney. Specific embodiments

[0022] In order to make the above objects, features and advantages of the present utility model more obvious and understandable, the specific embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

[0023] Secondly, the present utility model will be described in detail in conjunction with the schematic diagrams. When describing the embodiments of the present utility model in detail, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally in an unconventional proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present utility model herein. In addition, in actual production, three-dimensional spatial dimensions including length, width and depth should be included.

[0024] In order to make the purpose, technical solution and advantages of the present utility model clearer, the embodiments of the present utility model will be further described in detail below with reference to the accompanying drawings.

[0025] Figures 1 - 4 Shown is a schematic diagram of the entire structure of a wet desulfurization flue gas waste heat recovery and utilization device of the present utility model. Please refer to Figures 1 - 4, A wet flue gas waste heat recovery and utilization device of this embodiment includes a desulfurization tower 100. The flue gas discharge end of the desulfurization tower 100 is connected to a spray waste heat recovery tower 200. The spray waste heat recovery tower 200 includes a tower body 210. At the lower end inside the tower body 210, there is a horizontally arranged jet disk 230 connected to the flue gas discharge end of the desulfurization tower 100, and there are several spray nozzle units above the jet disk 230. Above the tower body 210, there are multiple spray trays 220 arranged from top to bottom. The absorption heat pump unit 300 includes a heat network return water pipe 310 for initially supplying the pump unit. The heat network return water pipe 310 has a water inlet unit and a water outlet unit. The absorption heat pump unit 300 transports the water introduced from the heat network return water pipe 310 to the spray trays 220 in each layer area through a set of water control pipes 320. The hot water after heat exchange in the spray waste heat recovery tower 200 is connected to the heat treatment unit of the absorption heat pump unit 300 through a set of return pipes 330. Among them, the flue gas after waste heat recovery in the spray waste heat recovery tower 200 is discharged through a chimney 400 arranged outside.

[0026] The output end of the desulfurization tower 100 has a boiler flue gas pipe 110 connected to a boiler 110, and the output end of the desulfurization tower 100 has an exhaust pipe 120 connected to the jet disk 230. Corresponding control valves are also equipped on the boiler flue gas pipe 110 and the exhaust pipe 120. It can be understood that the valves, instruments, etc. on the boiler flue gas pipe 110 and the exhaust pipe 120 connected to the desulfurization tower 100 should be made of high-temperature resistant and corrosion-resistant materials to ensure smooth and unobstructed flue gas flow, which is beneficial for the control system to accurately perform waste heat treatment and recovery operations according to the flue gas conditions. And, on this basis, the total control center of the control system can be led out. By real-time monitoring and analyzing system data, it can automatically adjust the spray water volume, flue gas flow rate, and heat pump operation parameters to ensure that the system is always in the optimal operating state.

[0027] The bottom of the inner cabin of the tower body 210 is provided with a water collecting tank 240 connected to the return pipe 330. It can be understood that the hot water after heat exchange will temporarily fall into the water collecting tank 240 at the bottom, waiting to be pumped and subjected to secondary heat treatment by the absorption heat pump unit 300 as needed. The spray plate 220 is composed of multiple inner and outer loop pipes, and a connecting support 222 is fixed between the inner and outer pipes. The bottom of the spray plate 220 also has spray heads 221 that are evenly distributed and connected to the bottom of the pipes; among them, the nozzle diameter of the spray head 221 at the bottom of the lowest spray plate 220 becomes smaller upwards, and the number of layers of the spray plate 220 is not less than three. It should be noted that since the flue gas rises from the bottom to the top, it is necessary to make full use of this physical feature to optimize the waste heat recovery efficiency. Specifically, the spray plate 220 located at the bottom can spray larger water droplets through the spray head 221 with a larger diameter. The dense larger water droplets can quickly absorb the initial flue gas and high-temperature heat. Subsequently, as the flue gas rises upward, its temperature will gradually decrease due to heat exchange. Therefore, the small-diameter spray head 221 can spray water droplets with smaller particle sizes at this time, which means that the coverage density of the water droplets is greater and the contact area with the flue gas is also larger, thereby deeply improving the absorption efficiency of the flue gas waste heat and realizing the maximum recovery and utilization of thermal energy.

[0028] On the basis of the above embodiment, further, the top of the jet disc 230 is also provided with evenly distributed pressure relief valves 231. In order to prevent the water falling from above from blocking the jet disc 230 nozzle, a corresponding pressure relief valve 231 is provided at each nozzle. The nozzle of the pressure relief valve 231 is located at the lower peripheral side of the valve cover. Under the action of hot air pressure, the flue gas in the jet disc 230 overflows through the pressure relief valve 231 and sprays to the peripheral side, so that the sprayed flue gas is dispersed, which is conducive to full contact and heat exchange with the spray system. Therefore, the waste heat recovery and utilization device can maximize the absorption of heat and water vapor latent heat in the flue gas and reduce the flue gas emission temperature by adopting a multi-layer spray structure and countercurrent heat exchange principle.

[0029] In this embodiment, the water control pipe group 320 includes a water supply main pipe 321 connected to the absorption heat pump unit 300 at one end, a diaphragm metering pump 322 arranged on the water supply main pipe 321, and a plurality of branch water pipes 323 are connected to the pipeline of the water supply main pipe 321. The other end of each branch water pipe 323 is connected to the corresponding spray disk 220. An electromagnetic flow valve 324 is also arranged on the branch water pipe 323. It can be understood that in order to more reasonably control the water spray output, the water supply main pipe 321 can perform unit total amount control on the initial return water output by the heat pump unit with the cooperation of the diaphragm metering pump 322. Of course, the unit total amount control is formed by adding the unit water amount required by each branch water pipe 323 and the electromagnetic flow valve 324 below, that is, the control system will determine the injection amount required for the spray disk 220 at each level through an algorithm according to the flue gas temperature and flue gas volume sprayed from the jet disk 230, thereby realizing the optimal recovery and utilization of waste heat.

[0030] In this embodiment, the absorption heat pump used can utilize an external low-grade heat source such as power plant steam as a driving source. Through the thermodynamic cycle process, the low-grade heat energy in the sprayed water can be efficiently upgraded to a high grade to meet various heat energy utilization requirements. This method using a closed-loop system can reduce water consumption and pollution risks. Specifically, after the sprayed water absorbs heat in the spray waste heat recovery tower 200, it undergoes efficient heat exchange through the heat pump unit and is upgraded to high-grade heat energy, which is then transferred to the external network water through the heat network return pipe 310. Thus, the water temperature is significantly increased and can be used for heating, hot water supply, power generation, etc. After cooling, it can return to the spray tower for recycling, forming a stable heat energy recovery cycle.

[0031] Furthermore, the top of the tower body 210 is also provided with an exhaust pipe 250 connected to the chimney 400. The flue gas after heat exchange and recovery in the spray waste heat recovery tower 200 is at a relatively low temperature at this time and basically has no value for waste heat recovery. Therefore, this part of the flue gas can be discharged through the exhaust pipe 250 and the chimney 400. Of course, in practical applications, a corresponding filtration and purification unit can also be provided on the exhaust pipe 250 to filter out harmful substances in the flue gas at the end, thereby ensuring clean flue gas emissions.

[0032] In summary, for a wet desulfurization flue gas waste heat recovery and utilization device in this embodiment, during use, the desulfurization tower 100 can guide the desulfurized flue gas to the jet tray 230. In this process, the initial water sprayed by the multi-layer spray trays 220 in the upper part of the spray tower can come into full contact with the flue gas sprayed by the jet tray 230. By adopting a multi-layer spray structure and the countercurrent heat exchange principle, the heat and latent heat of water vapor in the flue gas can be maximally absorbed, reducing the flue gas emission temperature; at the same time, after the sprayed water absorbs heat in the spray waste heat recovery tower 200, it undergoes efficient heat exchange through the heat pump unit and is upgraded to high-grade heat energy, which is then transferred to the external network water through the heat network return pipe 310. Thus, the water temperature is significantly increased and can be used for heating, hot water supply, power generation, etc. After cooling, it can return to the spray tower for recycling, forming a stable heat energy recovery cycle.

[0033] Although the present utility model has been described above with reference to the embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present utility model. In particular, as long as there is no structural conflict, the various features in the disclosed embodiments of the present utility model can be combined with each other in any way. The reason for not exhaustively describing the situations of these combinations in this specification is only to save space and resources. Therefore, the present utility model is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A wet flue gas waste heat recovery and utilization device, characterized in that: It comprises a desulfurization tower (100), wherein a smoke discharge end of the desulfurization tower (100) is connected to a spray waste heat recovery tower (200); A spray waste heat recovery tower (200) comprises a tower body (210), wherein the lower end of the tower body (210) is provided with a horizontally placed jet disk (230) connected to a flue gas discharge end of a desulfurization tower (100), and the upper part of the jet disk (230) is provided with a plurality of nozzle units, and a plurality of spray disks (220) are arranged from top to bottom on the upper part of the tower body (210); An absorption heat pump unit (300) comprises a heat network return pipe (310) for initially supplying a pump unit, the heat network return pipe (310) comprising a water inlet pipe unit and a water outlet pipe unit, the absorption heat pump unit (300) transports water introduced from the heat network return pipe (310) to the spray disks (220) of each layer through a water control pipe unit (320), and the hot water after heat exchange in the spray waste heat recovery tower (200) is connected to the heat treatment unit of the absorption heat pump unit (300) through a return pipe (330); The flue gas after waste heat recovery in the spray waste heat recovery tower (200) is discharged through a chimney (400) arranged outside.

2. A wet flue gas waste heat recovery and utilization device according to claim 1, characterized in that: The output end of the desulfurization tower (100) is provided with a boiler flue gas pipeline (110) connected to the boiler, and the output end of the desulfurization tower (100) is provided with a smoke exhaust pipe (120) connected to the jet disc (230), and the boiler flue gas pipeline (110) and the smoke exhaust pipe (120) are also provided with corresponding control valves.

3. The device for recovering waste heat from wet flue gas desulfurization according to claim 1 is characterized in that: The bottom of the inner cabin of the tower body (210) is provided with a water collecting pool (240) which is connected to the return pipe (330).

4. The device for recovering waste heat from wet flue gas desulfurization according to claim 1 is characterized in that: The spray plate (220) is composed of multiple inner and outer loop pipes, and a connecting support (222) is fixed between the inner and outer pipes. The bottom of the spray plate (220) also has spray heads (221) that are evenly distributed and connected to the bottom of the pipes. The diameter of the nozzle of the spray head (221) at the bottom of the lowest spray plate (220) gradually decreases upwards, and the number of layers of the spray plate (220) is not less than three.

5. The device for recovering waste heat from wet flue gas desulfurization according to claim 1 is characterized in that: The top of the jet disc (230) is also provided with evenly distributed pressure relief valves (231).

6. The device for recovering waste heat from wet flue gas desulfurization according to claim 1 is characterized in that: The water control pipe group (320) comprises a water supply main pipe (321) one end of which is connected to the absorption heat pump unit (300), and a diaphragm metering pump (322) arranged on the water supply main pipe (321); a plurality of branch water pipes (323) are connected to the pipeline of the water supply main pipe (321); the other end of each branch water pipe (323) is connected to a corresponding spray plate (220); and an electromagnetic flow valve (324) is also arranged on the branch water pipe (323).

7. The device for recovering waste heat from wet flue gas desulfurization according to claim 1 is characterized in that: The top of the tower body (210) is also provided with an exhaust pipe (250) connected to the chimney (400).

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