Flue gas waste heat recovery system

Abstract

The utility model discloses a flue gas waste heat recovery system which comprises a flue gas heat exchanger which comprises a shell, a heat exchange cavity is formed in the shell, a heat exchange plate is arranged in the heat exchange cavity, and first cooling liquid in the heat exchange plate can cool high-temperature flue gas; and the lithium bromide absorption type unit is connected with the flue gas heat exchanger, the lithium bromide absorption type unit can cool the first cooling liquid in the heat exchange plate, and meanwhile, the lithium bromide absorption type unit can cool the second cooling liquid used by a cooling liquid demand end. According to the technical scheme, the flue gas heat exchanger and the lithium bromide absorption type unit are combined for use, the flue gas is cooled through the flue gas heat exchanger so that the flue gas can reach the emission standard, and meanwhile, the lithium bromide absorption type unit and the second cooling liquid in the lithium bromide absorption type unit are cooled through the heat of the flue gas so that the cooling liquid demand end can use the cooling liquid. And full utilization of energy is realized, and great economic benefits are generated.

Description

Technical Field

[0001] This utility model relates to a waste heat recovery system, specifically a flue gas waste heat recovery system. Background Technology

[0002] Graphite anodes are currently the primary anode material in new energy vehicle batteries. Their production process involves high-temperature calcination to remove volatile components and increase carbon purity. Typically, the calcination temperature is 1200-1500℃, and the exhaust gas temperature reaches 600-800℃, containing a large amount of tar. This exhaust gas contains a significant amount of heat energy; direct release into the atmosphere would result in enormous energy waste and severe environmental impact, disrupting the local climate balance. Therefore, how to recover waste heat from the high-temperature exhaust gas and reduce energy consumption remains a key technical challenge. Utility Model Content

[0003] To overcome the above-mentioned shortcomings, the purpose of this utility model is to provide a flue gas waste heat recovery system for recovering waste heat from high-temperature flue gas.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a flue gas waste heat recovery system, comprising:

[0005] A flue gas heat exchanger includes a shell, inside which a heat exchange cavity is formed. A heat exchange plate is provided in the heat exchange cavity. A first coolant in the heat exchange plate can cool down the high-temperature flue gas. High-temperature flue gas refers to flue gas with a temperature higher than the emission standard. In this solution, high-temperature flue gas is flue gas with a temperature higher than 100°C.

[0006] A lithium bromide absorption chiller is provided, which is connected to the flue gas heat exchanger. The lithium bromide absorption chiller can cool the first coolant in the heat exchange plate and simultaneously cool the second coolant supplied to the coolant demand side.

[0007] This technical solution combines a flue gas heat exchanger and a lithium bromide absorption chiller. The flue gas heat exchanger cools the flue gas to meet emission standards, while the heat from the flue gas is used to cool the lithium bromide absorption chiller and the secondary coolant within the chiller for use by the coolant demand side. This achieves full utilization of energy and generates significant economic benefits.

[0008] Furthermore, an inspection port is provided on the upper side of the housing, the area of ​​which is not less than half the area of ​​the upper side of the housing, and the inspection port is located near the center of the upper side of the housing. A drain port is provided on the lower side of the housing.

[0009] Furthermore, an inspection cover is provided above the inspection port, and the inspection cover is hinged to the housing.

[0010] Furthermore, the heat exchange plate includes S-shaped hot water channels, with the inlet of the hot water channels located on the lower side of the shell and the outlet of the hot water channels located on the upper side of the shell, and the first coolant flows in a bottom-in, top-out direction.

[0011] Furthermore, the heat exchange chamber is provided with multiple heat exchange plates arranged side by side, and water distributors are provided at the liquid inlet and liquid outlet of the heat exchange plates respectively.

[0012] Furthermore, the distance between two adjacent heat exchange plates is 20-30mm, and the distance between two adjacent hot water channels is 30-40mm.

[0013] Furthermore, a flue gas inlet and a flue gas outlet are respectively provided at the left and right ends of the heat exchange chamber. A flue gas inlet flange is provided at the flue gas inlet for connecting to equipment that generates high-temperature flue gas during production, and a flue gas outlet flange is provided at the flue gas outlet for connecting to flue gas emission equipment.

[0014] Furthermore, a detection port is provided at the flue gas inlet and / or the flue gas outlet, and the detection port is connected to the flue gas outlet and / or the flue gas outlet.

[0015] Furthermore, the lithium bromide absorption chiller includes a first coolant inlet and a first coolant outlet. The first coolant outlet is connected to the inlet of the flue gas heat exchanger, and the first coolant inlet is connected to the outlet of the flue gas heat exchanger. The lithium bromide absorption chiller can cool the first coolant.

[0016] Furthermore, the lithium bromide absorption chiller includes a second coolant inlet and a second coolant outlet, which are respectively connected to the coolant demand side. The lithium bromide absorption chiller can cool the second coolant.

[0017] The beneficial effects of this utility model are:

[0018] 1) By using a flue gas heat exchanger and a lithium bromide absorption chiller in combination, the flue gas is cooled by the flue gas heat exchanger to meet emission standards. At the same time, the heat of the flue gas is used to cool the lithium bromide absorption chiller and the secondary coolant in the lithium bromide absorption chiller for use by the coolant demand side. This achieves full utilization of energy and generates great economic benefits.

[0019] 2) By setting up detection ports at the flue gas inlet and / or flue gas outlet to detect the flue gas at the flue gas inlet and / or flue gas outlet, the flue gas entering the flue gas heat exchanger can be monitored in real time to ensure that the cooled flue gas meets the emission standards.

[0020] 3) By setting inspection ports and drain ports on the shell, the heat exchange plates can be cleaned when tar condensation occurs and affects the heat exchange effect of the heat exchanger, so as to ensure the cooling effect of the flue gas heat exchanger. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments 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.

[0023] Figure 1 This is a perspective view of a flue gas heat exchanger according to an embodiment of the present invention;

[0024] Figure 2 This is a front view of a flue gas heat exchanger according to an embodiment of the present invention;

[0025] Figure 3 This is a side view of a flue gas heat exchanger according to an embodiment of the present invention;

[0026] Figure 4 This is a front view of a heat exchange plate according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the connection of a flue gas waste heat recovery system according to an embodiment of the present invention.

[0028] In the diagram: 1. Flue gas heat exchanger; 11. Flue gas inlet; 111. Flue gas inlet flange; 112. Inspection port; 12. Flue gas outlet; 121. Flue gas outlet flange; 13. Maintenance port; 14. Drain port; 15. Liquid inlet; 16. Liquid outlet; 17. Shell; 18. Heat exchange chamber; 19. Heat exchange plate; 2. Lithium bromide absorption chiller; 21. First coolant inlet; 22. First coolant outlet; 23. Second coolant inlet; 24. Second coolant outlet; 3. Coolant demand side; 4. Circulation pump. Detailed Implementation

[0029] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0030] See appendix Figure 1-4 As shown in this embodiment, a flue gas waste heat recovery system is used to cool the high-temperature flue gas generated during the production of graphite anodes, ensuring it meets emission standards. It can also cool high-temperature flue gas generated during other industrial production processes; this application does not specifically limit its application. The flue gas waste heat recovery system includes a flue gas heat exchanger 1 and a cooling device. The flue gas heat exchanger 1 cools the high-temperature flue gas.

[0031] In some embodiments, the flue gas heat exchanger 1 includes a rectangular shell 17, inside which a heat exchange chamber 18 is formed, and a heat exchange plate 19 is disposed within the heat exchange chamber 18. A flue gas inlet 11 and a flue gas outlet 12 are respectively disposed at the left and right ends of the heat exchange chamber 18. A flue gas inlet flange 111 is provided at the flue gas inlet 11 for connecting to equipment that generates high-temperature flue gas during production. The high-temperature flue gas enters the heat exchange chamber 18 through the flue gas inlet 11, is cooled by the heat exchange plate 19, and is discharged through the flue gas outlet 12. A flue gas outlet flange 121 is also provided at the flue gas outlet 12 for connecting to flue gas emission equipment.

[0032] In some embodiments, a detection port 112 is provided at the flue gas inlet 11 and the flue gas outlet 12, respectively. The detection port 112 is connected to the flue gas outlet 12 or the flue gas inlet 11 and is used to detect the flue gas at the flue gas inlet 11 and the flue gas outlet 12, so as to monitor the flue gas entering the flue gas heat exchanger 1 in real time and ensure that the cooled flue gas meets the emission standards.

[0033] In some embodiments, the heat exchange plate 19 includes S-shaped hot water channels. The inlet 15 of the hot water channels is located on the lower side of the housing 17, and the outlet 16 of the hot water channels is located on the upper side of the housing 17. The water flow direction is bottom inlet and top outlet, which is beneficial to the exhaust function of vaporization under high temperature conditions and prevents cavitation damage to local parts of the heat exchange plate 19.

[0034] In some embodiments, a plurality of heat exchange plates 19 are provided in the heat exchange chamber 18, and the plurality of heat exchange plates 19 are arranged side by side. A water distributor is provided at the liquid inlet 15 and liquid outlet 16 of the heat exchange plates 19 respectively, and the water flow of each heat exchange plate 19 is distributed through the water distributor to maintain the heat exchange plates 19 being able to cool the high-temperature flue gas evenly.

[0035] In some embodiments, the distance between two adjacent heat exchange plates 19 is 24 mm, and the distance between two adjacent hot water channels is 35 mm. By accurately controlling the distance between adjacent heat exchange plates 19 and the distance between adjacent hot water channels, the cooling effect of the heat exchange plates on the flue gas is ensured.

[0036] In some embodiments, an inspection port 13 is provided on the upper side of the housing 17, and an inspection cover is provided on the upper side after inspection. The inspection cover is connected by a flange. When tar condensation occurs and affects the heat exchange effect of the heat exchanger, the cover can be opened to clean the heat exchange plate 19. At the same time, a drain port 14 is provided on the lower side of the housing 17 to discharge the waste liquid generated from cleaning the flue gas heat exchanger.

[0037] In some embodiments, the area of ​​the access port 13 is not less than half the area of ​​the upper side surface of the housing 17, and the access port 13 is located near the center of the upper side surface of the housing 17 to facilitate maintenance operations.

[0038] See appendix Figure 5 As shown, in some embodiments, the cooling device includes a lithium bromide absorption chiller 2. The first coolant outlet 22 of the lithium bromide absorption chiller 2 is connected to the inlet 15 of the flue gas heat exchanger 1, and the first coolant inlet 21 of the lithium bromide absorption chiller 2 is connected to the outlet 16 of the flue gas heat exchanger 1. The flue gas heat exchanger 1 cools the 600°C high-temperature flue gas to 100°C before discharging it into the atmosphere. The high-temperature flue gas raises the temperature of the first coolant from 80°C to 87°C. The 87°C first coolant enters the lithium bromide chiller 3 via a circulation pump 4, generating a 7°C second coolant. The second coolant enters the coolant demand side via the second coolant outlet 23, and then circulates back into the lithium bromide chiller 3 via the second coolant inlet 24. The second coolant can be used by the coolant demand side 3, for example, for use in the summer air conditioning of the office area, reducing summer power consumption. It can also be used as process water in other process workshops that require chilled water. In this application, both the first and second coolants are water, but other coolants can also be used; this application does not limit the specific coolant used.

[0039] Based on the actual project operating parameters, the flue gas volume of a single roasting furnace is 2500 m³ / h, the flue gas inlet and outlet temperatures are 600 / 100℃, the flue gas load of a single roasting furnace is about 170 kW, and there are a total of 8 roasting furnaces. The heat load is 1360 kW. The hot water (first coolant) supply and return water temperatures are 80 / 87℃, the hot water flow rate is 152 m³ / h, the 87℃ hot water enters the lithium bromide absorption chiller unit 2 to produce 7℃ chilled water (second coolant) with a flow rate of 180 m³ / h, the chilled water return water temperature is 12℃, and the chilled water load is 1050 kW. Considering the total power consumption of the circulating water pump and lithium bromide absorption chiller is approximately 50kW, the net recovered heat is 1050-50=1000kW. Assuming a COP (coefficient of performance) of 5 for conventional chillers, this translates to a saving of 200kW in electricity. With an industrial electricity price of 1 yuan / kWh and 300 operating days per year, this results in annual electricity cost savings of 1.44 million yuan, generating significant economic benefits. Furthermore, the cooled, low-temperature flue gas meets environmental emission standards, reducing environmental pollution.

[0040] Therefore, this application uses a combination of flue gas heat exchanger 1 and lithium bromide absorption chiller 2. The flue gas heat exchanger 1 cools the flue gas to meet emission standards, while the heat from the flue gas is used to cool the lithium bromide absorption chiller 2, generating cooling water for use by the coolant demand side 3. This achieves full utilization of energy and generates significant economic benefits.

[0041] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0042] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A flue gas heat recovery system, characterized by, include: A flue gas heat exchanger (1) includes a shell (17), a heat exchange chamber (18) is formed inside the shell (17), a heat exchange plate (19) is provided inside the heat exchange chamber (18), and a first coolant in the heat exchange plate (19) can cool down the high-temperature flue gas. A lithium bromide absorption chiller (2) is connected to the flue gas heat exchanger (1). The lithium bromide absorption chiller (2) can cool the first coolant in the heat exchange plate (19) and cool the second coolant used by the coolant demand end (3).

2. The flue gas heat recovery system of claim 1, wherein, An inspection port (13) is provided on the upper side of the housing (17). The area of ​​the inspection port (13) is not less than half of the area of ​​the upper side of the housing (17), and the inspection port (13) is located close to the center of the upper side of the housing (17). A drain port (14) is provided on the lower side of the housing (17).

3. The flue gas heat recovery system of claim 2, wherein, An inspection cover is provided above the inspection port (13), and the inspection cover is hinged to the housing.

4. The flue gas heat recovery system of claim 1, wherein, The heat exchange plate (19) includes S-shaped hot water channels. The inlet (15) of the hot water channel is located on the lower side of the shell (17), and the outlet (16) of the hot water channel is located on the upper side of the shell (17). The first coolant flows from bottom to top.

5. The flue gas heat recovery system of claim 4, wherein, The heat exchange chamber (18) is provided with multiple heat exchange plates (19), which are arranged side by side. A water distributor is provided at the liquid inlet (15) and liquid outlet (16) of the heat exchange plates (19).

6. The flue gas heat recovery system of claim 5, wherein, The distance between two adjacent heat exchange plates (19) is 20~30mm, and the distance between two adjacent hot water channels is 30~40mm.

7. The flue gas heat recovery system of claim 1, wherein, A flue gas inlet (11) and a flue gas outlet (12) are respectively provided at the left and right ends of the heat exchange chamber (18). A flue gas inlet flange (111) is provided at the flue gas inlet (11) for connecting to equipment that generates high-temperature flue gas during production. A flue gas outlet flange (121) is provided at the flue gas outlet (12) for connecting to flue gas emission equipment.

8. The flue gas waste heat recovery system according to claim 7, characterized in that, A detection port (112) is provided at the flue gas inlet (11) and / or the flue gas outlet (12), and the detection port (112) is connected to the flue gas outlet (12) and / or the flue gas outlet (12).

9. The flue gas heat recovery system of claim 1, wherein, The lithium bromide absorption chiller (2) includes a first coolant inlet (21) and a first coolant outlet (22). The first coolant outlet (22) is connected to the inlet (15) of the flue gas heat exchanger (1), and the first coolant inlet (21) is connected to the outlet (16) of the flue gas heat exchanger (1). The lithium bromide absorption chiller (2) can cool the first coolant.

10. The flue gas waste heat recovery system according to any one of claims 1-9, characterized in that, The lithium bromide absorption chiller (2) includes a second coolant inlet (23) and a second coolant outlet (24). The second coolant inlet (23) and the second coolant outlet (24) are respectively connected to the coolant demand end (3). The lithium bromide absorption chiller (2) can cool the second coolant.

Images