Waste heat recovery equipment and natural gas hydrogen-doped combustion system

Abstract

The invention relates to waste heat recovery equipment and a natural gas hydrogen-doped combustion system. The waste heat recovery equipment comprises a first heat exchanger, a second heat exchanger and a spray tower, the first heat exchanger is provided with a first heat absorption side and a first heat release side, an outlet of the first heat absorption side is communicated with a combustion-supporting gas inlet of the combustor, the second heat exchanger is provided with a second heat absorption side and a second heat release side, and an inlet of the second heat release side is connected with a high-temperature flue gas outlet of the combustor. The spray tower is provided with a cooling water inlet, a smoke inlet, a smoke outlet and a spray water outlet, the smoke inlet is communicated with the outlet of the second heat release side, the spray water outlet is communicated with the inlet of the second heat absorption side, and the outlet of the second heat absorption side is communicated with the inlet of the first heat release side. According to the waste heat recovery equipment, two-stage waste heat recovery of high-temperature flue gas is achieved, the waste heat recovery efficiency is remarkably improved, combustion-supporting gas can be heated, accordingly, other combustion efficiency is improved, natural gas consumption and carbon emission are reduced, and the requirements for energy conservation and carbon reduction in the industrial high-temperature combustion process are met.

Description

Technical Field

[0001] This invention relates to the field of industrial kiln waste heat recovery technology, specifically to a waste heat recovery device and a natural gas hydrogen-blended combustion system. Background Technology

[0002] In the industrial sector, especially in high-energy-consuming industries such as glass, ceramics, and metallurgy, natural gas is often used as fuel. Combustion produces high-temperature flue gas. However, gas-fired kilns often use single-stage heat exchange or decentralized hot water recovery, which are complex in structure, have low heat exchange efficiency, and do not fully utilize the latent heat in the flue gas. The system integration needs to be improved. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a waste heat recovery device with a reasonable system design and simple structure. It realizes two-stage waste heat recovery of high-temperature flue gas, which significantly improves the waste heat recovery efficiency. At the same time, the first heat exchanger facilitates the heating of the combustion-supporting gas by the water after secondary heating, thereby improving the combustion efficiency of other combustion processes, reducing natural gas consumption and carbon emissions, meeting the energy-saving and carbon-reduction requirements of industrial high-temperature combustion processes, and has good engineering feasibility and industrial adaptability.

[0005] An embodiment of the present invention provides a natural gas hydrogen-blended combustion system.

[0006] The waste heat recovery device according to an embodiment of the present invention includes a first heat exchanger, a second heat exchanger, and a spray tower. The first heat exchanger has a first heat-absorbing side and a first heat-releasing side. The inlet of the first heat-absorbing side is used to introduce combustion-supporting gas, and the outlet of the first heat-absorbing side is used to connect to the combustion-supporting gas inlet of a burner. The second heat exchanger has a second heat-absorbing side and a second heat-releasing side. The inlet of the second heat-releasing side is used to connect to the high-temperature flue gas outlet of the burner. The spray tower has a cooling water inlet, a flue gas inlet, a flue gas outlet, and a spray water outlet. The cooling water inlet is used to introduce cooling water. The flue gas inlet is connected to the outlet of the second heat-releasing side, the spray water outlet is connected to the inlet of the second heat-absorbing side, and the outlet of the second heat-absorbing side is connected to the inlet of the first heat-releasing side.

[0007] The waste heat recovery equipment of this invention forms a combined heat exchange path of "two-stage indirect heat exchange + one-stage direct contact heat exchange" through a first heat exchanger, a second heat exchanger, and a spray tower. This not only efficiently recovers the sensible heat from the high-temperature flue gas, but also further recovers the latent heat of water vapor in the flue gas through the spray tower, achieving deep recovery of waste heat from the flue gas and significantly improving the overall thermal efficiency of the system. Furthermore, the recovered high-temperature hot water heat is effectively transferred to the combustion-supporting gas through the first heat exchanger, achieving efficient preheating of the combustion-supporting gas, increasing the initial combustion temperature, and optimizing the combustion conditions. This enhances the thermal intensity and stability of the mixed combustion of natural gas and hydrogen, thereby improving the combustion efficiency of the combustion gas in the burner, reducing natural gas consumption, and fully utilizing the waste heat from the flue gas to reduce energy loss and carbon emissions per unit output. It has good energy-saving and emission-reduction effects and meets the current green and low-carbon development needs of industrial kilns.

[0008] In some embodiments, the first heat exchanger is a first shell-and-tube heat exchanger, and the tube side of the first shell-and-tube heat exchanger is the first heat absorption side.

[0009] In some embodiments, the second heat exchanger is a second shell-and-tube heat exchanger, and the tube side of the second shell-and-tube heat exchanger is the second heat release side.

[0010] In some embodiments, the spray tower is equipped with a multi-stage spraying device.

[0011] In some embodiments, the waste heat recovery device further includes a control group, which includes a first temperature sensor, a valve, a first circulating pump, a second temperature sensor, and a third temperature sensor. The first temperature sensor, the valve, and the first circulating pump are connected in series and disposed at the cooling water inlet. The second temperature sensor is disposed at the inlet of the second heat release side, and the third temperature sensor is disposed at the spray water outlet.

[0012] In some embodiments, the waste heat recovery device further includes a second circulation pump, the inlet of which is connected to the spray water outlet, and the outlet of which is connected to the second heat absorption side inlet.

[0013] The natural gas hydrogen-blended combustion system of the present invention includes a burner and a waste heat recovery device. The burner has a combustion gas inlet, a combustion-supporting gas inlet and a high-temperature flue gas outlet. The combustion gas inlet is used to introduce natural gas and hydrogen. The outlet on the first heat-absorbing side is connected to the combustion-supporting gas inlet, and the inlet on the second heat-releasing side is connected to the high-temperature flue gas outlet of the burner.

[0014] In some embodiments, the burner is a roller kiln.

[0015] In some embodiments, the volume percentage of hydrogen is less than or equal to 25%. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a natural gas hydrogen-blended combustion system according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the temperature at various points in the natural gas hydrogen-blended combustion system of Embodiment 1 of the present invention;

[0018] Figure 3 This is a schematic diagram of the temperature at various points in the natural gas hydrogen-blended combustion system of Embodiment 2 of the present invention;

[0019] Figure label:

[0020] 1000. Natural gas hydrogen-blended combustion system;

[0021] 100. Waste heat recovery equipment;

[0022] 1. First heat exchanger; 11. Inlet of the first heat absorption side; 12. Outlet of the first heat absorption side; 13. Inlet of the first heat release side; 14. Outlet of the first heat release side.

[0023] 2. Second heat exchanger; 21. Inlet of the second heat absorption side; 22. Outlet of the second heat absorption side; 23. Inlet of the second heat release side; 24. Outlet of the second heat release side.

[0024] 3. Spray tower; 31. Cooling water inlet; 32. Smoke inlet; 33. Smoke outlet; 34. Spray water outlet; 4. Demisting device;

[0025] 200. Burner; 2001. Combustion gas inlet; 2002. Combustion-supporting gas inlet; 2003. High-temperature flue gas outlet. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following is a reference to the appendix. Figure 1 The waste heat recovery device 100 and the natural gas hydrogen-blended combustion system 1000 of the present invention are described in detail in the embodiments of the present invention.

[0028] The natural gas hydrogen-blended combustion system 1000 of this invention includes a burner 200 and a waste heat recovery device 100.

[0029] The burner 200 has a combustion gas inlet 2001, a combustion-supporting gas inlet 2002, and a high-temperature flue gas outlet 2003. The combustion gas inlet 2001 is used to introduce natural gas and hydrogen.

[0030] The waste heat recovery device 100 of this embodiment includes a first heat exchanger 1, a second heat exchanger 2, and a spray tower 3. The first heat exchanger 1 has a first heat-absorbing side and a first heat-releasing side. The inlet 11 of the first heat-absorbing side is used to introduce combustion gas, and the outlet 12 of the first heat-absorbing side is connected to the combustion gas inlet 2002 of the burner 200. The second heat exchanger 2 has a second heat-absorbing side and a second heat-releasing side. The inlet 23 of the second heat-releasing side is connected to the high-temperature flue gas outlet 2003 of the burner 200. The spray tower 3 has a cooling water inlet 31, a flue gas inlet 32, a flue gas outlet 33, and a spray water outlet 34. The cooling water inlet 31 is used to introduce cooling water. The flue gas inlet 32 ​​is connected to the outlet 24 of the second heat-releasing side. The spray water outlet 34 is connected to the inlet 21 of the second heat-absorbing side, and the outlet 22 of the second heat-absorbing side is connected to the inlet 13 of the first heat-releasing side.

[0031] In the operating state of the natural gas-hydrogen blending combustion system 1000 of this embodiment of the invention, combustion-supporting gas is introduced into the inlet 11 of the first heat exchanger 1 on the first heat absorption side, natural gas and hydrogen are introduced into the combustion gas inlet 2001 of the burner 200, and high-temperature flue gas is generated by the combustion of natural gas and hydrogen in the burner 200. Cooling water is introduced into the cooling water inlet 31 of the spray tower 3. The combustion-supporting gas is air, and the cooling water is room temperature water at 25°C.

[0032] The natural gas hydrogen-blended combustion system 1000 of this embodiment of the invention has a flue gas flow path and a heat exchanger flow path. The flue gas flow path is as follows: the high-temperature flue gas generated by the burner 200 flows sequentially through a high-temperature flue gas outlet 2003, an inlet 23 on the second heat-exerting side, the second heat-exerting side, an outlet 24 on the second heat-exerting side, a flue gas inlet 32, and a flue gas outlet 33. The heat exchanger flow path is as follows: a cooling water inlet 31, a spray tower 3, a spray water outlet 34, an inlet 21 on the second heat-absorbing side, the second heat-absorbing side, an outlet 22 on the second heat-absorbing side, an inlet 13 on the first heat-exerting side, and an outlet 14 on the first heat-exerting side.

[0033] Inside the second heat exchanger 2, the high-temperature flue gas generated by the burner 200 exchanges heat with the sprayed hot water discharged from the spray tower 3. The temperature of the high-temperature flue gas decreases, while the temperature of the hot water increases, achieving primary heat exchange and cooling of the high-temperature flue gas and recovering its sensible heat. Inside the spray tower 3, the flue gas discharged from the second heat exchanger 2 enters the spray tower 3. Cooling water is sprayed from top to bottom inside the spray tower 3, directly contacting the rising flue gas. The cooling water and flue gas exchange heat, further reducing the flue gas temperature and increasing the cooling water temperature, achieving secondary heat exchange and cooling of the flue gas and recovering the latent heat and residual sensible heat of the water vapor in the flue gas.

[0034] After being heated once by the spray tower 3 and then twice by the second heat exchanger 2, the water has a high temperature. The high-temperature water enters the first heat-releasing side of the first heat exchanger 1. Inside the first heat exchanger 1, the high-temperature water on the first heat-releasing side exchanges heat with the combustion gas on the first heat-absorbing side. The temperature of the water decreases and the temperature of the combustion gas increases, thereby increasing the initial temperature of the combustion gas entering the burner 200, which in turn enhances the combustion efficiency of the combustion gas.

[0035] Therefore, the waste heat recovery device 100 of this embodiment of the invention recovers the sensible heat of high-temperature flue gas through heat exchange between the second heat exchanger 2 and the wall, and recovers the latent heat and residual sensible heat of the flue gas by direct contact between water and flue gas through the spray tower 3, thus realizing two-stage waste heat recovery of high-temperature flue gas, significantly improving the waste heat recovery efficiency. At the same time, the first heat exchanger 1 facilitates the heating of the combustion-supporting gas by the water after secondary heating, thereby improving the combustion efficiency of other combustion processes, reducing natural gas consumption and carbon emissions, and meeting the energy-saving and carbon-reduction requirements of industrial high-temperature combustion processes.

[0036] Furthermore, the burner 200 is a roller kiln with an operating temperature range of 800-1100℃.

[0037] In the combustion gas formed by natural gas and hydrogen, the volume percentage of hydrogen is less than or equal to 25%. The combustion gas is composed of a mixture of natural gas and hydrogen, with the hydrogen component accounting for no more than 25% of the combustion gas, to ensure the safety and stability of combustion.

[0038] The first heat exchanger 1 is a first shell-and-tube heat exchanger, with the tube side of the first shell-and-tube heat exchanger being the first heat-absorbing side. The combustion-supporting gas is on the tube side of the first shell-and-tube heat exchanger, while high-temperature water from the second heat-absorbing side of the second heat exchanger 2 is on the shell side of the first shell-and-tube heat exchanger. The combustion-supporting gas and the high-temperature water exchange heat through the indirect wall, and after absorbing heat, the combustion-supporting gas enters the roller kiln.

[0039] The second heat exchanger 2 is a second shell-and-tube heat exchanger, with the tube side of the second shell-and-tube heat exchanger being the second heat release side. The high-temperature flue gas discharged from the burner 200 is on the tube side of the second shell-and-tube heat exchanger, while the hot water from the spray tower 3 is on the shell side of the second shell-and-tube heat exchanger. The high-temperature flue gas and water undergo indirect heat exchange, resulting in a cooling of the high-temperature flue gas and a further increase in the temperature of the hot water.

[0040] Both the first heat exchanger 1 and the second heat exchanger 2 are shell-and-tube heat exchangers. The use of a shell-and-tube structure can improve heat exchange efficiency and structural stability, thereby further improving the waste heat recovery efficiency of the waste heat recovery device 100 for high-temperature flue gas in this embodiment of the invention.

[0041] The spray tower 3 is equipped with a multi-stage spraying device, which can increase the contact area between flue gas and cooling water, improve the condensation heat absorption efficiency of flue gas, enhance the recovery efficiency of latent heat and residual sensible heat of flue gas, and further improve the waste heat recovery efficiency of the waste heat recovery device 100 of this embodiment of the invention for high-temperature flue gas.

[0042] Specifically, spray tower 3 is equipped with a three-stage spraying device.

[0043] The exhaust port 33 of the spray tower 3 is connected to a demister 4, and the flue gas after spraying is discharged into the atmosphere after passing through the demister 4.

[0044] In some embodiments, the waste heat recovery device 100 further includes a control group (not shown in the figure), which includes a first temperature sensor, a valve, a first circulating pump, a second temperature sensor and a third temperature sensor. The first temperature sensor, the valve and the first circulating pump are connected in series and disposed at the cooling water inlet 31. The second temperature sensor is disposed at the inlet 23 on the second heat release side, and the third temperature sensor is disposed at the spray water outlet 34.

[0045] The first circulating pump pumps cooling water into the spray tower 3. A first temperature sensor detects the temperature of the cooling water, and a valve controls the flow rate. A second temperature sensor detects the temperature of the high-temperature flue gas generated by the burner 200, and a third temperature sensor detects the temperature of the warm water entering the inlet 21 of the second heat absorption side after spraying. Therefore, based on the temperature of the high-temperature flue gas from the burner 200, the flow rate of the cooling water entering the spray tower 3 is adjusted in real time to control the water temperature after heat exchange, ensuring efficient temperature operation of the system.

[0046] In some embodiments, the waste heat recovery device 100 further includes a second circulation pump (not shown in the figure), the inlet of which is connected to the spray water outlet 34, and the outlet of which is connected to the inlet of the second heat absorption side. The second circulation pump pumps the hot water collected at the bottom of the spray tower 3 to the second heat absorption side of the second heat exchanger 2, providing power for water circulation.

[0047] The operation of the natural gas hydrogen-blended combustion system 1000 according to a specific embodiment of the present invention will be described below.

[0048] Example 1: See Figure 2 The specific temperatures of the gas and cooling water entering the natural gas hydrogen-blended combustion system 1000 of this embodiment of the invention are as follows: the combustion-supporting gas is air, the air temperature is 25°C, the combustion gas temperature is 25°C, the composition of the combustion gas is methane, the hydrogen blending ratio is 0, and the cooling water temperature is 25°C.

[0049] Inside the first heat exchanger 1, the water entering the first heat-releasing side has a temperature of 76.43°C, while the air entering the first heat-absorbing side has a temperature of 25°C. Heat exchange occurs between the air and the hot water. After heat exchange, the air temperature is 54.15°C, increasing the temperature at which the air enters the burner 200. The water temperature after heat exchange is 70.22°C, still retaining some thermal energy. The water, after being discharged from the outlet 14 of the first heat-releasing side, can be sent to downstream users, for example, for heating.

[0050] Inside the burner 200, methane and hydrogen are burned to produce high-temperature flue gas at 250°C. The high-temperature flue gas enters the second heat release side of the second heat exchanger 2 from the high-temperature flue gas outlet 2003.

[0051] Inside the second burner 2, the water entering the second heat-absorbing side is at a temperature of 51.04℃. The warm water undergoes heat exchange with the high-temperature flue gas through a partition wall, achieving primary waste heat recovery from the high-temperature flue gas. After heat exchange in the second heat exchanger 2, the temperature of the flue gas discharged drops to 148.97℃, and then it enters the spray tower 3. The water discharged after heat exchange in the second heat exchanger 2 rises to a temperature of 76.43℃, and then enters the first heat-releasing side of the first heat exchanger 1.

[0052] Inside spray tower 3, 25°C cooling water sprays onto flue gas at 148.97°C, directly exchanging heat to achieve secondary waste heat recovery. After spraying and heat exchange, the water temperature rises to 51.04°C and, after exiting spray tower 3, enters the second heat absorption side of the second heat exchanger 2. The flue gas temperature drops to 51.04°C after spraying, meeting environmental emission requirements, and is then discharged into the atmosphere after being demisted by a demister.

[0053] Example 2: See Figure 3 The specific temperatures of the gas and cooling water entering the natural gas hydrogen-blended combustion system 1000 of this embodiment of the invention are as follows: the combustion gas is air, the air temperature is 25°C, the combustion gas temperature is 25°C, the composition of the combustion gas is methane and hydrogen, the hydrogen blending ratio is 10%, that is, the volume ratio of hydrogen to the volume of combustion gas (methane and hydrogen) is 10%, and the cooling water temperature is 25°C.

[0054] Inside the first heat exchanger 1, the water entering the first exothermic side has a temperature of 75.85°C, while the air entering the first absorbent side has a temperature of 25°C. Heat exchange occurs between the air and the hot water. The air temperature after heat exchange is 53.97°C, increasing the temperature of the air entering the burner 200. The water temperature after heat exchange is 69.85°C, and the water is discharged from the outlet 14 of the first exothermic side.

[0055] Inside the burner 200, methane and hydrogen are burned to produce high-temperature flue gas at 250°C. The high-temperature flue gas enters the second heat release side of the second heat exchanger 2 from the high-temperature flue gas outlet 2003.

[0056] Inside the second burner 2, the water entering the second heat-absorbing side is at a temperature of 51.05℃. The warm water exchanges heat with the high-temperature flue gas through a partition wall, achieving primary waste heat recovery from the high-temperature flue gas. After heat exchange in the second heat exchanger 2, the temperature of the flue gas discharged drops to 148.52℃, and then it enters the spray tower 3. After heat exchange in the second heat exchanger 2, the temperature of the water discharged rises to 75.85℃, and then it enters the first heat-releasing side of the first heat exchanger 1.

[0057] Inside spray tower 3, 25°C cooling water sprays onto flue gas at 148.52°C, directly exchanging heat to achieve secondary waste heat recovery. After spraying and heat exchange, the water temperature rises to 51.05°C and, after exiting spray tower 3, enters the second heat absorption side of the second heat exchanger 2. The flue gas temperature drops to 51.05°C after spraying, meeting environmental emission requirements, and is then discharged into the atmosphere after being demisted by a demister.

[0058] Therefore, the natural gas hydrogen-blended combustion system of the present invention has the following beneficial effects:

[0059] 1. By constructing two shell-and-tube heat exchangers, a spray tower, and a glass kiln in series, a combined heat exchange path of "two-stage indirect heat exchange + one-stage direct contact heat exchange" is formed. This not only enables efficient recovery of sensible heat from high-temperature flue gas, but also further recovery of latent heat of water vapor in the flue gas through the spray tower, achieving deep recovery of waste heat from the flue gas and significantly improving the overall thermal efficiency of the system.

[0060] 2. The combustion air is set to pass through the first heat exchanger, which effectively transfers the heat from the recovered high-temperature hot water to the combustion gas, thereby achieving efficient preheating of the combustion gas, increasing the initial combustion temperature, optimizing combustion conditions, and thus enhancing the thermal intensity and stability of the natural gas and hydrogen mixture combustion.

[0061] 3. It can improve combustion efficiency, reduce natural gas consumption, and make full use of flue gas waste heat, thereby reducing energy loss and carbon emission levels per unit output. It has good energy-saving and emission-reduction effects and meets the current green and low-carbon development needs of industrial kilns.

[0062] 4. It uses a mixture of natural gas and hydrogen for combustion in a certain proportion, with the hydrogen component not exceeding 25%, effectively balancing calorific value enhancement and combustion safety. It is suitable for various industrial high-temperature heating processes and expands the application space of clean energy gas in the field of industrial kilns.

[0063] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0065] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0067] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0068] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A waste heat recovery device (100), characterized in that, include: The first heat exchanger (1) has a first heat absorption side and a first heat release side. The inlet (11) of the first heat absorption side is used to introduce combustion gas, and the outlet (12) of the first heat absorption side is used to connect to the combustion gas inlet (2002) of the burner (200). The second heat exchanger (2) has a second heat absorption side and a second heat release side, and the inlet (23) of the second heat release side is used to connect to the high-temperature flue gas outlet (2003) of the burner (200). and The spray tower (3) has a cooling water inlet (31), a flue gas inlet (32), a flue gas outlet (33), and a spray water outlet (34). The cooling water inlet (31) is used to introduce cooling water. The flue gas inlet (32) is connected to the outlet (24) of the second heat-releasing side. The spray water outlet (34) is connected to the inlet (21) of the second heat-absorbing side. The outlet (22) of the second heat-absorbing side is connected to the inlet (13) of the first heat-releasing side.

2. The waste heat recovery equipment (100) according to claim 1, characterized in that, The first heat exchanger (1) is a first shell-and-tube heat exchanger, and the tube side of the first shell-and-tube heat exchanger is the first heat absorption side.

3. The waste heat recovery equipment (100) according to claim 1, characterized in that, The second heat exchanger (2) is a second shell-and-tube heat exchanger, and the tube side of the second shell-and-tube heat exchanger is the second heat release side.

4. The waste heat recovery equipment (100) according to claim 1, characterized in that, The spray tower (3) is equipped with a multi-stage spraying device.

5. The waste heat recovery equipment (100) according to claim 1, characterized in that, The system further includes a control group, which includes a first temperature sensor, a valve, a first circulating pump, a second temperature sensor, and a third temperature sensor. The first temperature sensor, the valve, and the first circulating pump are connected in series and located at the cooling water inlet (31). The second temperature sensor is located at the inlet (23) on the second heat release side, and the third temperature sensor is located at the spray water outlet (34).

6. The waste heat recovery equipment (100) according to claim 1, characterized in that, It further includes a second circulation pump, the inlet of which is connected to the spray water outlet (34), and the outlet of which is connected to the second heat absorption side inlet.

7. A natural gas hydrogen-blended combustion system (1000), characterized in that, include: A burner (200) having a combustion gas inlet (2001), a combustion-supporting gas inlet (2002), and a high-temperature flue gas outlet (2003), wherein the combustion gas inlet (2001) is used to introduce natural gas and hydrogen; and Waste heat recovery device (100), wherein the waste heat recovery device (100) is the waste heat recovery device (100) according to any one of claims 1 to 6, wherein the outlet (12) of the first heat absorption side is connected to the combustion gas inlet (2002), and the inlet (23) of the second heat release side is connected to the high temperature flue gas outlet (2003) of the burner (200).

8. The natural gas hydrogen-blended combustion system (1000) according to claim 7, characterized in that, The burner (200) is a roller kiln.

9. The natural gas hydrogen-blended combustion system (1000) according to claim 7, characterized in that, The volume percentage of hydrogen is less than or equal to 25%.

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