Desulfurization slurry waste heat heating system

Abstract

The utility model relates to a desulfurization slurry waste heat heating system which comprises a desulfurization tower, a slurry heat exchanger is arranged on a desulfurization slurry spraying pipeline, the system is provided with a heating water return waste heat bypass, and the heating water return waste heat bypass is communicated with a heating water return main pipeline through a switching valve. After being introduced through the heating water return waste heat bypass, heating water return water directly or indirectly exchanges slurry waste heat in the slurry heat exchanger, and then the heating water return water return water is merged into the heating water return main pipeline through the heating water return waste heat bypass. Return heating water is heated through waste heat of desulfurized slurry, the working capacity of a heat supply network is improved, and the purposes of increasing the heating area, heating cleanly, reducing the enterprise energy cost and increasing the enterprise income are achieved.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery and utilization in wet desulfurization, specifically to a desulfurization slurry waste heat heating system. Background Technology

[0002] The limestone-gypsum wet desulfurization process is the most widely used desulfurization process in thermal power plants. After the high-temperature flue gas of 120℃-150℃ is washed by the desulfurization slurry in the desulfurization tower, the temperature drops to 50℃ and then it is discharged from the chimney. The waste heat in the flue gas is not effectively recovered and utilized, resulting in energy waste.

[0003] With the increasing demand for heating in winter, many heating companies are facing a heating shortage and are looking for more heat sources to meet the demand.

[0004] Against this backdrop, how to utilize the waste heat from desulfurization slurry in heating systems is one of the issues that heating companies are considering. However, due to the presence of a large amount of solid particles in the desulfurization slurry and its strong corrosiveness, coupled with constraints imposed by complex factors such as the spatial location of the desulfurization unit, water balance, and heat balance, applying the waste heat from the desulfurization slurry to heating systems remains a challenge, despite its substantial volume.

[0005] Currently, the main technology for applying waste heat from desulfurization slurry to the heating sector is flash evaporation combined with a heat pump. The basic principle is to flash-evaporate the water in the slurry into steam, extracting the waste heat to supply the heating water return system. While this technology can extract heat completely, the technical route is complex, requires a large area for modification, and the flash evaporation causes slurry concentration, necessitating additional water replenishment. This results in high operating costs, extensive maintenance, and substantial initial investment, making it less practical.

[0006] Therefore, developing a desulfurization slurry waste heat heating system with high waste heat utilization rate, simple process route, low cost and strong practicality remains the goal pursued in this field. Utility Model Content

[0007] This utility model aims to address the problems existing in the prior art by providing a desulfurization slurry waste heat heating system. It utilizes the waste heat of the desulfurization slurry to heat the heating water return, thereby improving the working capacity of the heating network, increasing the heating area, providing clean heating, reducing enterprise energy costs, and increasing enterprise profits.

[0008] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows:

[0009] A desulfurization slurry waste heat heating system includes a desulfurization tower and a slurry heat exchanger installed on the spray pipe of the desulfurization slurry, characterized in that...

[0010] The system is equipped with a heating water return waste heat bypass, which is connected to the heating water return main pipeline via a switching valve.

[0011] After the heating water return water is introduced through the heating water return water waste heat bypass, it directly or indirectly exchanges the waste heat of the slurry in the slurry heat exchanger, and then connects to the heating water return water main pipeline through the heating water return water waste heat bypass.

[0012] According to the technical solution of this utility model, the desulfurization tower is equipped with multiple slurry spraying pipelines, and slurry heat exchangers are installed on some or all of the slurry spraying pipelines.

[0013] This invention does not impose any particular restrictions on the slurry heat exchanger; any slurry heat exchanger commonly used in the field can be used. Preferably, a plate heat exchanger is used, and even more preferably, a straight-channel plate heat exchanger is used.

[0014] According to the technical solution of this utility model, after the heating water return absorbs heat, it is pumped into the main heating water return pipeline.

[0015] According to the technical solution of this utility model, the direct exchange of slurry waste heat in the slurry heat exchanger means that the heating water return water is introduced into the slurry heat exchanger after passing through the heating water return water waste heat bypass, and then enters the heating water return water main pipeline after exchanging for slurry waste heat, and then passes through the heating water return water waste heat bypass to enter the heating water return water main pipeline.

[0016] According to one embodiment of the present invention, before the heating water return water enters the slurry heat exchanger, it is first subjected to heat exchange and cooling treatment in the form of full or partial heat exchange, then enters the slurry heat exchanger to exchange for slurry waste heat, and finally enters the heating water return water main pipeline via the heating water return water waste heat bypass.

[0017] By performing heat exchange and cooling treatment on all or part of the heating water return water, the heat extraction of the slurry is no longer limited by the temperature of the heating water return water, allowing for deeper extraction of waste heat from the slurry. Furthermore, while implementing waste heat heating from the slurry, it can also simultaneously meet the heating needs of other cold-end parts of the plant, achieving comprehensive utilization of waste heat. Utilizing the waste heat of the slurry to heat the heating water return water increases the return water temperature, enhances the heating network's working capacity, reduces energy costs, and increases enterprise profits. Cooling the slurry lowers the flue gas temperature, reducing nitrogen oxide emissions and desulfurization water consumption, resulting in certain environmental benefits. It effectively solves the problem of high heating water return water temperature and limited or no heat exchange space for the desulfurization slurry.

[0018] Preferably, the heat exchange and cooling treatment is performed by a refrigerant regulator. The refrigerant regulator is connected in series or parallel with the slurry heat exchanger, and performs heat exchange and cooling treatment on the entire or a portion of the heating water return water through the refrigerant regulator.

[0019] This invention does not impose any particular restrictions on the refrigerant regulator.

[0020] According to another embodiment of this utility model, the heat exchange and cooling process is completed by a heat pump. Before the heating water return water is introduced into the slurry heat exchanger via the heating water return water waste heat bypass, it first enters the heat pump for cooling, then enters the slurry heat exchanger to absorb the waste heat of the slurry, flows out of the slurry heat exchanger, enters the heat pump again to absorb waste heat, and finally returns to the heating water return main pipeline via the heating water return water waste heat bypass.

[0021] Furthermore, according to another embodiment of this utility model, when a heat pump is used to perform heat exchange and cooling treatment on the heating water return water, a refrigerant regulator is installed on the heating water return water waste heat bypass to perform dual cooling treatment on the heating water return water. The refrigerant regulator can be installed before or after the heat pump. The heating water return water is introduced into the slurry heat exchanger through the heating water return water waste heat bypass, and is cooled by both the heat pump and the refrigerant regulator. Then it enters the slurry heat exchanger to absorb the waste heat of the slurry. After flowing out of the slurry heat exchanger, it re-enters the heat pump to absorb waste heat, and finally returns to the heating water return water main pipeline through the heating water return water waste heat bypass.

[0022] According to the technical solution of this utility model, the indirect exchange of waste heat in the slurry heat exchanger refers to using a heat transfer water device to exchange the waste heat of the slurry within the heat exchanger, with the heat transfer water forming a closed loop between the slurry heat exchanger and the heat pump. Heating water return water is introduced into the heat pump via a heating water return water waste heat bypass to absorb heat, and after flowing out of the heat pump, it returns to the main heating water return water pipeline via the heating water return water waste heat bypass. The heating water return water only circulates within the heat pump to absorb waste heat. The heat transfer water from the heat pump enters the slurry heat exchanger to exchange heat with the slurry and absorb waste heat, then enters the heat pump, where the waste heat is transferred to the heating water return water.

[0023] Installing a heat transfer water device can prevent the desulfurization slurry from coming into direct contact with the heating water return, thus avoiding problems caused by leakage.

[0024] According to one embodiment of this utility model, before the heating water return water enters the heat pump, it first undergoes heat exchange and cooling treatment in its entirety or in part, then enters the heat pump to absorb heat. After flowing out of the heat pump, it flows through the heating water return water waste heat bypass and into the main heating water return water pipeline. Performing heat exchange and cooling treatment on the entirety or in part of the heating water return water effectively solves the problem of high heating water return water temperature and small or no heat exchange space in the heat pump, enabling deep extraction of waste heat from the desulfurization slurry.

[0025] Preferably, the heat exchange and cooling treatment is performed by a refrigerant regulator. The refrigerant regulator is connected in series or parallel with the slurry heat exchanger, and performs heat exchange and cooling treatment on the entire or a portion of the heating water return water through the refrigerant regulator.

[0026] According to one embodiment of this utility model, while performing deep recovery of waste heat from the slurry, a demister water collection and reuse system is set up for the desulfurization tower to solve the problem of reduced evaporation and water balance imbalance caused by slurry cooling and flue gas temperature reduction.

[0027] A demister is installed above the spray pipe inside the desulfurization tower, and a water collector is installed below the demister. The water collector collects the flushing water after the demister has worked and outputs it to the outside of the desulfurization tower.

[0028] This utility model does not have any particular restrictions on the water collector. Any container that can hold water, such as a tray, water trough, water pan, or a modified bottom demister into a water-collecting demister, can be used as the water collector.

[0029] In a further preferred embodiment, the water collector collects the flushing water from the demister and outputs it to a clarifier located outside the desulfurization tower. The treated flushing water is then buffered in a process water tank and pumped back to the demister via a demister flushing water pump, thus creating a cyclical process. A drain valve is located below the clarifier to remove residue from it.

[0030] Technical effects of this utility model:

[0031] Utilizing the waste heat from the slurry to heat the heating water return water increases the return water temperature, enhances the heating network's capacity, reduces energy costs, and increases enterprise profits. Cooling the slurry lowers the flue gas temperature, reducing nitrogen oxide emissions and desulfurization water consumption, offering environmental benefits. By performing heat exchange and cooling treatment on all or part of the heating water return water, the heat extraction from the slurry is no longer limited by the temperature of the heating water return water, allowing for deeper extraction of waste heat. Furthermore, while implementing slurry waste heat heating, it can also meet the heating needs of other cold-end components within the plant, achieving comprehensive utilization of waste heat. This effectively solves the problem of high heating water return water temperatures and limited or no heat exchange space for the desulfurization slurry.

[0032] A demister water collection and reuse system is added to the desulfurization tower to maximize the recovery of slurry waste heat, increasing the waste heat recovery by about 50%-100%, and solving the problem of not being able to deeply recover slurry waste heat due to the limited water balance of the desulfurization tower. Attached Figure Description

[0033] Figure 1 The schematic diagram of the desulfurization slurry waste heat heating system shown in Embodiment 1 of this utility model.

[0034] Figure 2 The schematic diagram of the desulfurization slurry waste heat heating system shown in Embodiment 2 of this utility model.

[0035] Figure 3 The schematic diagram of the desulfurization slurry waste heat heating system shown in Embodiment 3 of this utility model.

[0036] Figure 4 The schematic diagram of the desulfurization slurry waste heat heating system shown in Embodiment 4 of this utility model.

[0037] Figure 5 The schematic diagram of the desulfurization slurry waste heat heating system shown in Embodiment 5 of this utility model.

[0038] Figure 6 The schematic diagram of the desulfurization slurry waste heat heating system shown in Embodiment 6 of this utility model.

[0039] Figure 7 Another embodiment of the desulfurization tower used in the desulfurization slurry waste heat heating system described in this utility model.

[0040] Figure 8 This utility model is based on Figure 7 The diagram shows the structure of the waste heat heating system for the desulfurization slurry in the desulfurization tower design.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Desulfurization tower, 2. Slurry spray pipeline, 3. Slurry pump, 4. Slurry heat exchanger, 5. Heating water return waste heat bypass, 6. Switching valve, 7. Booster pump, 8. Refrigerant regulator, 9. Heat pump, 10. Heat medium water device, 11. Demister, 12. Water collector, 13. Clarifier, 14. Drain valve, 15. Demister flushing water pump, 16. Process water tank, 17. Demister spray pipeline. Detailed Implementation

[0043] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0044] Example 1

[0045] Figure 1 A schematic diagram of the structure of a desulfurization slurry waste heat heating system provided by this utility model is shown.

[0046] The desulfurization slurry waste heat heating system includes:

[0047] The desulfurization tower 1 is equipped with multiple slurry spraying pipelines 2. The desulfurization slurry is transported from the bottom of the desulfurization tower 1 to the upper part of the desulfurization tower 1 via the slurry pump 3 and the slurry spraying pipelines 2 for spraying operation. One or more slurry heat exchangers 4 are installed on part or all of the slurry spraying pipelines 2. The system also includes a heating water return waste heat bypass 5, which is connected to the heating water return main pipeline via a switching valve 6.

[0048] After the heating water return water is introduced through the heating water return water waste heat bypass 5, it enters the heat exchange slurry heat exchanger 4 to exchange for slurry waste heat. After flowing out of the slurry heat exchanger 4, it flows through the heating water return water waste heat bypass 5 and into the heating water return water main pipeline.

[0049] This invention does not impose any particular restrictions on the slurry heat exchanger 4; any slurry heat exchanger commonly used in the field can be used. Preferably, a plate heat exchanger is used, and even more preferably, a straight-channel plate heat exchanger is used.

[0050] After absorbing the heat from the slurry, the heating water return water is pumped into the main heating water return water pipeline via booster pump 7.

[0051] Example 2

[0052] Figure 2 A schematic diagram of another desulfurization slurry waste heat heating system of this utility model is shown.

[0053] Compared with Example 1, the difference between the two is that: before the heating water return water enters the slurry heat exchanger 4, it undergoes heat exchange and cooling treatment in full or in part. After the heat exchange and cooling treatment, it enters the slurry heat exchanger 4 to absorb the residual heat of the slurry. After flowing out of the slurry heat exchanger 4, it flows through the heating water return water waste heat bypass 5 and into the heating water return water main pipeline.

[0054] By performing heat exchange and cooling treatment on all or part of the heating water return water, the heat extraction from the slurry is no longer limited by the temperature of the heating water return water, allowing for deeper extraction of waste heat from the slurry. Furthermore, while implementing waste heat heating from the slurry, it can also meet the heating needs of other cold ends within the plant, achieving comprehensive utilization of waste heat.

[0055] Utilizing the waste heat of the slurry to heat the heating water return water increases the return water temperature, enhances the heating network's operational capacity, reduces enterprise energy costs, and increases enterprise profits. Slurry cooling lowers the flue gas temperature, reducing nitrogen oxide emissions and desulfurization water consumption, thus offering certain environmental benefits. It effectively solves the problem of high heating water return water temperature and limited or nonexistent heat exchange space for the desulfurization slurry.

[0056] In this embodiment, a refrigerant regulator 8 is used to complete the heat exchange and cooling operation of the heating water return water. The refrigerant regulator 8 is connected in series or parallel with the slurry heat exchanger 4, and the refrigerant regulator 8 pre-cools the entire or a portion of the heating water return water.

[0057] This invention does not impose any particular restrictions on the refrigerant regulator 8, and adopts a refrigerant regulator commonly used in the field.

[0058] Example 3

[0059] Figure 3 A schematic diagram of the structure of a desulfurization slurry waste heat heating system provided by this utility model is shown.

[0060] Compared with Example 1, the difference between the two is that: before the heating water return water enters the slurry heat exchanger 4, it undergoes heat exchange and cooling treatment in full or in part. After cooling treatment, it enters the slurry heat exchanger 4 to exchange the residual heat of the slurry, and finally enters the heating water return water main pipeline via the heating water return water waste heat bypass 5.

[0061] In this embodiment, the heat exchange and cooling process is completed by the heat pump 9. Before the heating water return water is introduced into the slurry heat exchanger 4 via the heating water return water waste heat bypass 5, it first enters the heat pump 9 for cooling, then enters the slurry heat exchanger 4 to absorb the waste heat of the slurry, and after flowing out of the slurry heat exchanger 4, it enters the heat pump 9 again to absorb waste heat, and finally returns to the heating water return main pipeline via the heating water return water waste heat bypass 5.

[0062] Example 4

[0063] Figure 4 A schematic diagram of the structure of a desulfurization slurry waste heat heating system provided by this utility model is shown.

[0064] Compared with Example 3, the difference is that a refrigerant regulator 8 is installed on the heating water return waste heat bypass 5 to perform double cooling treatment on the heating water return. The refrigerant regulator 8 is set before or after the heat pump 9. The heating water return is introduced into the slurry heat exchanger 4 through the heating water return waste heat bypass 5. After being cooled by the heat pump 9 and the refrigerant regulator 8, it enters the slurry heat exchanger 4 to absorb the waste heat of the slurry. After flowing out of the slurry heat exchanger 4, it enters the heat pump 9 again to absorb the waste heat. Finally, it is led back to the heating water return main pipeline through the heating water return waste heat bypass 5.

[0065] Example 5

[0066] Figure 5 A schematic diagram of the structure of a desulfurization slurry waste heat heating system provided by this utility model is shown.

[0067] The desulfurization slurry waste heat heating system includes a desulfurization tower 1, which is equipped with multiple slurry spraying pipelines 2. The desulfurization slurry is transported from the bottom of the desulfurization tower 1 to the upper part of the desulfurization tower 1 via a slurry pump 3 and the slurry spraying pipelines 2 for spraying. One or more slurry heat exchangers 4 are installed on part or all of the slurry spraying pipelines 2. The system also includes a heating water return waste heat bypass 5, which is connected to the heating water return main pipeline via a switching valve 6.

[0068] This embodiment also includes a heat transfer water device 10, which exchanges the waste heat of the slurry in the slurry heat exchanger 4. The heat transfer water forms a closed loop between the slurry heat exchanger 4 and the heat pump 9. The heating water return water is introduced through the heating water return water waste heat bypass 5, enters the heat pump 9 to absorb heat, and flows out of the heat pump 9, then flows through the heating water return water waste heat bypass 5 and into the main heating water return water pipeline.

[0069] The heating water return water circulates only within the heat pump 9 to absorb waste heat. The heat transfer medium water enters the slurry heat exchanger 4 to exchange heat with the slurry and absorb waste heat, and then enters the heat pump 9, through which the waste heat is transferred to the heating water return water.

[0070] The installation of the heat transfer water device 10 can prevent the desulfurization slurry from coming into direct contact with the heating water return water, thus avoiding problems caused by leakage.

[0071] Example 6

[0072] Figure 6 A schematic diagram of the structure of a desulfurization slurry waste heat heating system provided by this utility model is shown.

[0073] Compared with Example 5, the difference is that a refrigerant regulator 8 is installed on the heating water return waste heat bypass 5 to cool the heating water return. Before the heating water return is introduced into the heat pump 9 through the heating water return waste heat bypass 5, it is cooled by the refrigerant regulator 8, and then enters the heat pump 9 to absorb heat. After flowing out of the heat pump 9, it is led back to the heating water return main pipeline through the heating water return waste heat bypass 5.

[0074] Example 7

[0075] Figure 7 , Figure 8 This invention illustrates a schematic diagram of a desulfurization tower structure used in the desulfurization slurry waste heat heating system provided by this utility model. Figure 1 Compared to the desulfurization towers shown, the difference lies in:

[0076] The desulfurization tower 1 is equipped with a demister 11 and a demister spray pipe 17. The demister 11 is located below the demister spray pipe 17, and a water collector 12 is located below the demister 11. The water collector 12 collects the flushing water from the demister 11 after its operation and outputs it to the outside of the desulfurization tower 1. Preferably, the water collector 12 collects the flushing water from the demister 11 and outputs it to a clarifier 13 located outside the desulfurization tower 1. The treated flushing water is buffered in a process water tank 15 and then pumped back to the demister 11 by a demister flushing water pump 16, circulating continuously. A drain valve 14 is located below the clarifier 13 for removing residue from the clarifier 13.

[0077] Figure 8 The desulfurization tower shown is applied in the desulfurization slurry waste heat heating system of this utility model. The slurry spraying pipeline 2 is located below the demister 11, and the other settings are the same as in Embodiment 1.

[0078] The technical solution of this utility model has been described in detail above, and the principle and implementation method of this utility model have been explained through specific embodiments. However, the embodiments are only used to help understand this utility model and should not be construed as limiting this utility model.

Claims

1. A desulfurization slurry waste heat heating system, comprising a desulfurization tower, wherein a slurry heat exchanger is installed on the slurry spray pipeline of the desulfurization tower, characterized in that: The system is equipped with a heating water return waste heat bypass, which is connected to the heating water return main pipeline via a switching valve. After the heating water return water is introduced through the heating water return water waste heat bypass, it directly or indirectly exchanges the waste heat of the slurry in the slurry heat exchanger, and then connects to the heating water return water main pipeline through the heating water return water waste heat bypass.

2. The desulfurization slurry waste heat heating system as described in claim 1, characterized in that: The direct exchange of slurry waste heat in the slurry heat exchanger refers to the process where heating water return water is introduced through the heating water return water waste heat bypass, enters the slurry heat exchanger to exchange for slurry waste heat, and then flows out of the slurry heat exchanger and merges into the heating water return water main pipeline through the heating water return water waste heat bypass.

3. The desulfurization slurry waste heat heating system as described in claim 2, characterized in that: Before the heating water return water enters the slurry heat exchanger, it first undergoes heat exchange and cooling treatment in the form of full or partial flow. Then it enters the slurry heat exchanger to exchange for residual heat from the slurry. After flowing out of the slurry heat exchanger, it flows through the heating water return water residual heat bypass and into the heating water return water main pipeline.

4. The desulfurization slurry waste heat heating system as described in claim 3, characterized in that: The heat exchange and cooling process is completed by a refrigerant regulator, which is connected in series or in parallel with the slurry heat exchanger.

5. The desulfurization slurry waste heat heating system as described in claim 3, characterized in that: The heat exchange and cooling process is completed by a heat pump. Before the heating water return water is introduced into the slurry heat exchanger via the heating water return water waste heat bypass, it first enters the heat pump for cooling, then enters the slurry heat exchanger to absorb the waste heat of the slurry, flows out of the slurry heat exchanger, enters the heat pump again to absorb waste heat, and finally returns to the heating water return main pipeline via the heating water return water waste heat bypass.

6. The desulfurization slurry waste heat heating system as described in claim 5, characterized in that: When a heat pump is used to exchange heat and cool the heating water return water, a refrigerant regulator is installed on the heating water return water waste heat bypass to perform dual cooling treatment on the heating water return water. The refrigerant regulator is installed before or after the heat pump. The heating water return water is introduced into the slurry heat exchanger before passing through the heating water return water waste heat bypass. It is then cooled by both the heat pump and the refrigerant regulator before entering the slurry heat exchanger to absorb the waste heat of the slurry.

7. The desulfurization slurry waste heat heating system as described in claim 1, characterized in that: The indirect exchange of waste heat in the slurry heat exchanger refers to the use of a heat transfer water device to exchange the waste heat of the slurry within the heat exchanger. The heat transfer water forms a closed loop between the heat exchanger and the heat pump. The heat transfer water enters the heat exchanger to absorb the waste heat of the slurry, and then enters the heat pump for circulation. The heating water return water is introduced through the heating water return water waste heat bypass and then enters the heat pump to absorb heat. The heating water return water only circulates in and out of the heat pump to absorb waste heat. The heat pump transfers the waste heat to the heating water return water. After flowing out of the heat pump, the heating water return water is connected to the main heating water return water pipeline through the heating water return water waste heat bypass.

8. The desulfurization slurry waste heat heating system as described in claim 7, characterized in that: Before the heating water return enters the heat pump, it first undergoes heat exchange and cooling treatment in full or partial form, then enters the heat pump to absorb heat, and after flowing out of the heat pump, it flows through the heating water return waste heat bypass and into the heating water return main pipeline.

9. The desulfurization slurry waste heat heating system as described in claim 8, characterized in that: The heat exchange and cooling process is completed by a refrigerant regulator.

10. The desulfurization slurry waste heat heating system according to any one of claims 1-9, characterized in that: A demister is installed inside the desulfurization tower, and a water collector is installed below the demister. The water collector collects the flushing water after the demister spray pipeline has been working and outputs it to a clarifier installed outside the desulfurization tower. Then, the treated flushing water is transported to the demister spray pipeline for circulation.

Images