Desulfurization waste heat recovery system

Abstract

The utility model discloses a desulfurization waste heat recovery system. The desulfurization waste heat recovery system comprises a desulfurization tower, heat exchange equipment and a circulation loop. The desulfurization tower is provided with a slurry inlet and a slurry outlet opposite to the slurry inlet; the heat exchange equipment is connected with the slurry inlet through a first pipeline and connected with the slurry outlet through a second pipeline; the circulation loop is connected with the heat exchange equipment; wherein the heat exchange equipment is used for enabling desulfurization slurry in the first pipeline to enter the desulfurization tower through the second pipeline after heat exchange with a heat exchange medium in the circulation loop, so that waste heat in the desulfurization tower can be extracted by utilizing the desulfurization slurry through the heat exchange equipment and the circulation loop, and the utilization rate of the waste heat of the desulfurization tower is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of desulfurization equipment, in particular to a desulfurization waste heat recovery system. Background Art

[0002] Wet desulfurization uses limestone or lime slurry to absorb sulfur dioxide in flue gas to generate calcium sulfite, which is further oxidized to calcium sulfate and recovered in the form of gypsum. It is the most mature and stable desulfurization process in the world, with a desulfurization effect of more than 90%. The desulfurization slurry pump sucks the slurry at the bottom of the desulfurization tower and pressurizes it, then sprays it into the desulfurization tower through the spray head. It reacts chemically with the flue gas in the tower to generate gypsum, and the sulfur dioxide in the flue gas solidifies in the gypsum and is discharged. However, the waste heat in the flue gas evaporates into the atmosphere in the form of water vapor, and the heat utilization rate is low. Utility Model Content

[0003] In view of this, the utility model aims to solve one of the problems in the related art at least to a certain extent. To this end, the purpose of the utility model is to provide a desulfurization waste heat recovery system.

[0004] The present application provides a desulfurization waste heat recovery system. The desulfurization waste heat recovery system includes a desulfurization tower, a heat exchange device and a circulation loop. The desulfurization tower is provided with a slurry inlet and a slurry outlet opposite to the slurry inlet; the heat exchange device is connected to the slurry inlet through a first pipeline, and is connected to the slurry outlet through a second pipeline; the circulation loop is connected to the heat exchange device; wherein the heat exchange device is used to allow the desulfurization slurry in the first pipeline to exchange heat with the heat exchange medium in the circulation loop and then enter the desulfurization tower through the second pipeline.

[0005] In certain embodiments, the slurry outlet in the desulfurization waste heat recovery system is arranged at the bottom of the desulfurization tower, the slurry inlet is arranged above the slurry outlet, and the desulfurization tower is also provided with a flue gas inlet located between the slurry inlet and the slurry outlet.

[0006] In certain embodiments, the desulfurization waste heat recovery system further includes a smoke inlet pipe connected to the smoke inlet and a fan disposed on the smoke inlet pipe, wherein the fan is used to introduce the smoke into the desulfurization tower.

[0007] In certain embodiments, the bottom of the desulfurization tower is in an inverted cone shape.

[0008] In certain embodiments, a first pump is disposed on the first pipeline, and the first pump is used to pump the desulfurization slurry flowing out of the heat exchange device into the desulfurization tower.

[0009] In certain embodiments, a second pump is provided on the second pipeline, and the second pump is used to pump the desulfurization slurry in the desulfurization tower into the heat exchange device.

[0010] In certain embodiments, the desulfurization waste heat recovery system further includes a third pipeline connecting the first pipeline and the second pipeline, and a switch is provided on the third pipeline, and the switch is used to control the on-off of the third pipeline.

[0011] In certain embodiments, the desulfurization waste heat recovery system further includes a heat pump heating device, which includes an evaporator and a condenser connected to the evaporator, the evaporator is connected to the circulation loop, and the condenser is connected to the pipeline to be heated.

[0012] In certain embodiments, the pipeline to be heated includes an input pipe and an output pipe, the input pipe is connected to the condenser and the shaft seal heater, and the output pipe is connected to the condenser and the deoxygenation tank.

[0013] In certain embodiments, the desulfurization waste heat recovery system further includes a chimney, and a flue gas outlet is disposed on the top of the desulfurization tower, and the flue gas outlet is connected to the chimney.

[0014] Thus, in the desulfurization waste heat recovery system of the embodiment of the present application, the heat exchange equipment is used to allow the desulfurization slurry in the first pipeline to exchange heat with the heat exchange medium in the circulation loop and then enter the desulfurization tower through the second pipeline, so that the desulfurization slurry can be used through the heat exchange equipment and the circulation loop to extract the waste heat in the desulfurization tower, thereby improving the utilization rate of the waste heat of the desulfurization tower.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0017] Figure 1 It is a schematic structural diagram of a desulfurization waste heat recovery system according to an embodiment of the present application.

[0018] Description of reference numerals:

[0019] Desulfurization waste heat recovery system 200;

[0020] Desulfurization tower 10, slurry inlet 11, slurry outlet 12, flue gas inlet 13, flue gas outlet 14; heat exchange equipment 20; circulation loop 30; first pipeline 40, first pump 41; second pipeline 50, second pump 51; third pipeline 60, switch 61; smoke inlet pipe 70, fan 71; chimney 80; heat pump heating device 90, evaporator 91, condenser 92; pipeline to be heated 100, input pipe 101, output pipe 102. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, and may refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection, or mutual communication; direct connection, indirect connection through an intermediate medium, internal connection between two elements, or interaction between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0024] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] See also Figure 1 The present application discloses a desulfurization waste heat recovery system 200. The desulfurization waste heat recovery system 200 includes a desulfurization tower 10, a heat exchange device 20, and a circulation loop 30. The desulfurization tower 10 is provided with a slurry inlet 11 and a slurry outlet 12 opposite to the slurry inlet 11; the heat exchange device 20 is connected to the slurry inlet 11 through a first pipeline 40, and is connected to the slurry outlet 12 through a second pipeline 50; the circulation loop 30 is connected to the heat exchange device 20; wherein the heat exchange device 20 is used to allow the desulfurization slurry in the second pipeline 50 to exchange heat with the heat exchange medium in the circulation loop 30 and then enter the desulfurization tower 10 through the first pipeline 40.

[0027] Specifically, the desulfurization tower 10 is a tower-type device for desulfurizing industrial waste gas, and is mainly used to treat sulfur dioxide in flue gas. The desulfurization tower 10 can remove sulfur dioxide from flue gas through a specific process and desulfurizer, thereby reducing the pollution of flue gas to the environment. The working principle of the desulfurization tower 10 of wet desulfurization is to convert sulfur dioxide in flue gas into sulfate by gas-liquid contact and chemical reaction between flue gas and desulfurization slurry with oxidizing effect.

[0028] In the wet desulfurization tower 10, the nozzle sprays a certain amount of desulfurization slurry (usually an alkaline solution, such as limestone slurry) into the tower in the form of mist to form a uniform spray layer. After the flue gas is discharged from the combustion equipment, it enters the desulfurization tower 10. In the desulfurization tower 10, the flue gas is fully in contact with the sprayed desulfurization slurry droplets to form a gas-liquid two-phase contact interface. In this process, sulfur dioxide is absorbed by the desulfurization slurry. This reaction is usually a redox reaction. Taking limestone as an example, the calcium carbonate reacts with sulfur dioxide and water to form calcium sulfite, which is then oxidized to calcium sulfate, and calcium sulfate combines with water to form gypsum.

[0029] The heat exchange device 20 is, for example, a direct heating machine, which is a device that can directly and efficiently heat the fluid. The working principle of the heat exchange device 20 is to directly heat the fluid flowing through it through a specific heating element or heat source (such as the desulfurization slurry mentioned above), so that the temperature of the fluid is quickly raised to a set value.

[0030] Specifically, in the above embodiment, the heat exchange device 20 heats the heat exchange medium (such as water) in the circulation loop 30 to a certain temperature before flowing out. The heat exchange device 20 can use the desulfurization slurry carrying heat as a heat source at one end, and heat the heat exchange medium flowing through the heat exchange device 20 to a preset temperature at the other end to achieve heat transfer.

[0031] When the desulfurization slurry is sprayed into the desulfurization tower 10, only a small amount of the desulfurization slurry may react to form gypsum, and most of it is discharged from the slurry outlet 12, flows into the heat exchange device 20 through the second pipeline 50, and after heat exchange with the heat exchange medium in the circulation loop 30 in the heat exchange device 20, enters the desulfurization tower 10 from the slurry inlet 11 through the first pipeline 40.

[0032] In summary, the desulfurized slurry after desulfurization treatment in the desulfurization tower 10 is used as the heat source of the heat exchange device 20, and the heat of the desulfurized slurry can be transferred to the water in the circulation loop 30 through the heat exchange effect of the heat exchange device 20. The heat that may have been wasted is recovered and converted into usable energy, reducing heat emissions, reducing environmental pollution, improving the utilization rate of the waste heat of the desulfurization tower 10, reducing dependence on traditional energy, reducing production costs, and improving the economic benefits of the enterprise.

[0033] like Figure 1 As shown, in some embodiments, the slurry outlet 12 in the desulfurization waste heat recovery system 200 is arranged at the bottom of the desulfurization tower 10, the slurry inlet 11 is arranged above the slurry outlet 12, and the desulfurization tower 10 is further provided with a flue gas inlet 13 located between the slurry inlet 11 and the slurry outlet 12. In this way, by arranging the slurry inlet 11 above the slurry outlet 12, the slurry can have sufficient contact area and contact time with the flue gas below when it is pressurized by a water pump and sprayed into the desulfurization tower 10 through a spray head, thereby improving the desulfurization efficiency.

[0034] In certain embodiments, the desulfurization waste heat recovery system 200 further includes a smoke inlet pipe 70 connected to the smoke inlet 13 and a fan 71 disposed on the smoke inlet pipe 70 , and the fan 71 is used to introduce the smoke into the desulfurization tower 10 .

[0035] Specifically, the smoke inlet pipe 70 may be connected to the boiler, and a fan 71 is disposed on the smoke inlet pipe 70 , and the fan 71 may introduce the smoke into the desulfurization tower 10 for desulfurization.

[0036] In certain embodiments, the bottom of the desulfurization tower 10 is in an inverted cone shape.

[0037] Specifically, after the slurry enters the desulfurization tower 10, it is sprayed to the bottom of the desulfurization tower 10 in the form of water drops through the nozzle. The bottom of the desulfurization tower 10 has a certain liquid level of about 0-200mm. The internal structure of the desulfurization tower 10 is an inverted cone, which can reduce the retention of slurry in the desulfurization tower 10 and prevent accumulation and precipitation during operation. Secondly, after the desulfurization tower 10 is shut down, in order to prevent the slurry from being retained in the desulfurization tower 10 from precipitating, the wall of the desulfurization tower 10 can be flushed and diluted from the inlet pipe flushing port to completely eliminate the retained liquid. Finally, if the slurry crystals are precipitated and attached to the wall of the desulfurization tower 10, during the operation process: the desulfurization tower 10 is a container of about 5m*4m*4m, and the slurry channel is wide, and the crystal attachment will not affect the slurry circulation in the short term. After the desulfurization tower 10 is shut down: because the desulfurization tower 10 is equipped with a manhole door, the internal space is sufficient, and the internal attachment can be checked through the manhole door after the shutdown, and acid washing, alkali washing or cleaning with tools inside can be performed.

[0038] In certain embodiments, a first pump 41 is disposed on the first pipeline 40 , and the first pump 41 is used to pump the desulfurization slurry flowing out of the heat exchange device 20 into the desulfurization tower 10 .

[0039] Specifically, the first pipeline 40 is connected to the slurry inlet 11 of the desulfurization tower 10, and the slurry inlet 11 is located above the slurry outlet 12 of the desulfurization tower 10. The desulfurization slurry flowing out of the heat exchange device 20 needs to overcome the natural gravity to complete the recovery of the desulfurization slurry and introduce it into the desulfurization tower 10. Therefore, a first pump 41 needs to be set on the first pipeline 40 connecting the heat exchange device 20 and the desulfurization tower 10 to provide power for the flow of the desulfurization slurry.

[0040] In some embodiments, a second pump 51 is provided on the second pipeline 50 , and the second pump 51 is used to pump the desulfurization slurry in the desulfurization tower 10 into the heat exchange device 20 .

[0041] Specifically, the desulfurization slurry after sufficient contact with the flue gas flows out from the slurry outlet 12 of the desulfurization tower 10. The slurry outlet 12 is located below the desulfurization tower 10. In order to pump it into the heat exchange device 20, a second pump 51 needs to be arranged on the second pipeline 50 to provide power for the desulfurization slurry.

[0042] See also Figure 1 In some embodiments, the desulfurization waste heat recovery system 200 further includes a third pipeline 60 connecting the first pipeline 40 and the second pipeline 50 . A switch 61 is provided on the third pipeline 60 . The switch 61 is used to control the on-off of the third pipeline 60 .

[0043] When the heat exchange device 20 is required to perform heat exchange, the switch 61 is closed, and the desulfurized slurry does not pass through the third pipeline 60. When heat exchange is not required, the switch 61 is opened, so that when the desulfurized slurry flows out from the slurry outlet 12 of the desulfurization tower 10 through the second pipeline 50, it no longer flows to the heat exchange device 20, but goes through the third pipeline 60, and then directly flows back to the slurry inlet 11 of the desulfurization tower 10 from the first pipeline 40, thereby directly recycling the desulfurized slurry without the heat exchange process.

[0044] In some embodiments, the desulfurization waste heat recovery system 200 also includes a heat pump heating device 90, which includes an evaporator 91 and a condenser 92 connected to the evaporator 91, the evaporator 91 is connected to the circulation loop 30, and the condenser 92 is connected to the pipeline 100 to be heated.

[0045] The heat obtained by the heat exchange device 20 from the desulfurized slurry through heat exchange can be applied to the heat pump heating device 90, which may include an evaporator 91, a condenser 92 and a compressor connected to the two. The evaporator 91 is a key component in the heat pump heating device 90, and its main function is to absorb heat. The evaporator 91 absorbs heat from a low-temperature heat source such as water by contacting and connecting with an external medium. In this process, the refrigerant in the evaporator 91 is converted from a liquid state to a gaseous state, completing the absorption of heat, and the refrigerant enters the compressor in a gaseous form. The compressor is the power source of the heat pump system, responsible for compressing the low-temperature and low-pressure gas in the evaporator 91 into a high-temperature and high-pressure gas, and the gas enters the condenser 92. The condenser 92 releases the heat in the compressed high-temperature and high-pressure refrigerant, so that the refrigerant changes from a gaseous state back to a liquid state, and heats the medium to be heated 100.

[0046] In this way, the heat pump heating device 90 can absorb the heat of the water in the circulation loop 30 for use in the pipeline 100 to be heated.

[0047] In certain embodiments, the pipeline 100 to be heated includes an input pipe 101 and an output pipe 102 , wherein the input pipe 101 connects the condenser 92 and the shaft seal heater, and the output pipe 102 connects the condenser 92 and the deoxygenation tank.

[0048] In one embodiment, the input of the condenser 92 is the outlet water of the shaft seal heater, which can have a temperature of about 35 degrees. At the same time, with a certain amount of electrical energy input from the heat pump heating device 90, water with a temperature of about 79.5 degrees can be output and used as the inlet water for deoxygenation in the deaerator tank.

[0049] Specifically, the shaft seal heater is a device that recovers the shaft seal leakage steam and uses its heat to heat the condensed water. The main function of the shaft seal heater is to heat the condensed water or desalted water, recover the heat of the shaft seal leakage steam, thereby reducing the shaft seal leakage steam and heat loss. The heated condensed water or desalted water will be discharged through the water outlet. In the above embodiment, the temperature can be about 35 degrees, which can be used as the input of the condenser 92 for the heat pump heating device 90.

[0050] The deaerator is a device used to remove dissolved oxygen from water in a water treatment system. It can prevent corrosion and other adverse reactions and improve the working efficiency and life of the equipment. The deaerator can use some chemical methods, such as passing the incoming water through a special sponge iron filter material to cause an oxidation reaction between the oxygen in the water and the iron to remove oxygen. The inlet water temperature should not be lower than 70 degrees, because too low a temperature may result in poor deoxygenation. The condenser 92 can heat the water output by the output pipe 102 at around 79.5 degrees by combining a certain amount of electrical energy input, meeting the inlet water temperature requirement of the deaerator.

[0051] In some embodiments, the desulfurization waste heat recovery system 200 further includes a chimney 80, and a flue gas outlet 14 is provided on the top of the desulfurization tower 10, and the flue gas outlet 14 is connected to the chimney 80. After the flue gas is desulfurized in the desulfurization tower 10, it is discharged into the chimney 80 again through the flue gas outlet 14 of the desulfurization tower 10. It not only utilizes the waste heat of the flue gas, but also absorbs the harmful gas sulfur dioxide in the flue gas, which has the significance of energy saving and environmental protection.

[0052] The above embodiments only express several implementation methods of the utility model, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A desulfurization waste heat recovery system, characterized in that: include: A desulfurization tower is provided with a slurry inlet and a slurry outlet opposite to the slurry inlet; a heat exchange device, the heat exchange device being connected to the slurry inlet through a first pipe and to the slurry outlet through a second pipe; and A circulation loop is connected to the heat exchange device; wherein the heat exchange device is used to allow the desulfurization slurry in the second pipeline to exchange heat with the heat exchange medium in the circulation loop and then enter the desulfurization tower through the first pipeline.

2. The desulfurization waste heat recovery system according to claim 1, characterized in that: The slurry outlet is arranged at the bottom of the desulfurization tower, the slurry inlet is arranged above the slurry outlet, and the desulfurization tower is further provided with a flue gas inlet located between the slurry inlet and the slurry outlet.

3. The desulfurization waste heat recovery system according to claim 2 is characterized in that: The desulfurization waste heat recovery system also includes a smoke inlet pipe connected to the smoke inlet and a fan arranged on the smoke inlet pipe, and the fan is used to introduce the smoke into the desulfurization tower.

4. The desulfurization waste heat recovery system according to claim 1, characterized in that: The bottom of the desulfurization tower is in an inverted cone shape.

5. The desulfurization waste heat recovery system according to claim 1, characterized in that: The first pipeline is provided with a first pump, and the first pump is used to pump the desulfurization slurry flowing out of the heat exchange device into the desulfurization tower.

6. The desulfurization waste heat recovery system according to claim 1, characterized in that: The second pipeline is provided with a second pump, and the second pump is used to pump the desulfurization slurry in the desulfurization tower into the heat exchange equipment.

7. The desulfurization waste heat recovery system according to claim 1, characterized in that: The desulfurization waste heat recovery system further includes a third pipeline connecting the first pipeline and the second pipeline. A switch is provided on the third pipeline, and the switch is used to control the on and off of the third pipeline.

8. The desulfurization waste heat recovery system according to claim 1, characterized in that: The desulfurization waste heat recovery system also includes a heat pump heating device, which includes an evaporator and a condenser connected to the evaporator. The evaporator is connected to the circulation loop, and the condenser is connected to the pipeline to be heated.

9. The desulfurization waste heat recovery system according to claim 8, characterized in that: The pipeline to be heated includes an input pipe and an output pipe, wherein the input pipe is connected to the condenser and the shaft seal heater, and the output pipe is connected to the condenser and the deaerator tank.

10. The desulfurization waste heat recovery system according to claim 1, characterized in that: The desulfurization waste heat recovery system also includes a chimney. A flue gas outlet is disposed on the top of the desulfurization tower, and the flue gas outlet is connected to the chimney.

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