Sintering flue gas waste heat utilization system and method of using same

Abstract

The application provides a sintering flue gas waste heat utilization system and a use method thereof, wherein the sintering flue gas waste heat utilization system comprises a flue gas pipeline arranged between a sintering main exhaust fan and a desulfurization tower; an air-water heat exchanger is arranged on the flue gas pipeline, the air-water heat exchanger is provided with a circulating water pipeline, a water-water heat exchanger and a circulating pump group are arranged on the circulating water pipeline; first and second temperature detectors are arranged on the flue gas pipeline and located on the front and back sides of the air-water heat exchanger, and the temperature of sintering flue gas entering the desulfurization tower is controlled through the first and second temperature detectors and the circulating pump group. The sintering flue gas waste heat utilization system can solve the problem that the waste heat of sintering flue gas of an existing sintering machine cannot be effectively utilized.

Description

Technical Field

[0001] This invention relates to the field of sintering flue gas technology in the steel industry, and more specifically, to a sintering flue gas waste heat utilization system and its application method. Background Technology

[0002] The sintering process in the steel industry generates a large amount of sintering flue gas. The flue gas produced by the sintering machine is characterized by its large volume, complex composition, and high temperature. The temperature of the sintering flue gas at the outlet of the main sintering exhaust fan varies depending on the sintering machine. Under normal circumstances, the temperature of the sintering flue gas is between 150 and 160°C, but it can reach 180°C under emergency conditions.

[0003] In addition, the state has also imposed restrictions on the emission concentration of pollutants in sintering flue gas. Therefore, all enterprises currently have desulfurization facilities installed to support sintering flue gas. At present, there are three desulfurization technologies used at home and abroad: dry desulfurization, semi-dry desulfurization, and wet desulfurization. Each desulfurization technology has strict temperature limits for sintering flue gas. Specifically, the dry desulfurization process requires the sintering flue gas temperature at the inlet tower to not exceed 135℃, the semi-dry desulfurization process requires the sintering flue gas temperature to not be lower than 120℃, and the wet desulfurization process requires the sintering flue gas temperature to not be lower than 90℃. Therefore, the sintering flue gas has a certain amount of waste heat that can be utilized before entering the desulfurization system.

[0004] Currently, the waste heat of sintering flue gas is not effectively utilized in various desulfurization processes. Dry desulfurization uses cold air or heat exchangers to reduce the flue gas temperature to below 135°C, but the waste heat of the flue gas is not only not effectively utilized, but also increases the load on the desulfurization tower. In addition, the heat before semi-dry desulfurization and wet desulfurization is also not effectively utilized.

[0005] Therefore, there is an urgent need for a method that can effectively utilize the waste heat of sintering flue gas before it enters the desulfurization system. Summary of the Invention

[0006] In view of the above problems, the purpose of this invention is to provide a sintering flue gas waste heat utilization system and its usage method, so as to solve the problem that the waste heat of sintering flue gas in existing sintering machines cannot be effectively utilized.

[0007] The sintering flue gas waste heat utilization system provided by the present invention includes a flue gas duct installed between the sintering main exhaust fan and the desulfurization tower; a gas-water heat exchanger is installed on the flue gas duct, the gas-water heat exchanger is configured with a circulating water pipeline, and a water-to-water heat exchanger and a circulating pump set are installed on the circulating water pipeline; furthermore...

[0008] A first temperature detector and a second temperature detector are installed on the flue gas duct, located on the front and rear sides of the gas-water heat exchanger. The temperature of the sintering flue gas introduced into the desulfurization tower is controlled by the first temperature detector, the second temperature detector, and the circulating pump group.

[0009] Furthermore, in a preferred embodiment, the water-to-water heat exchanger is equipped with a first cold source pipeline, and a cooling tower is installed on the cold source pipeline; and,

[0010] A first pressurizing pump is installed on the cold source inlet side of the water-to-water heat exchanger. A first shut-off valve and a second shut-off valve are installed before and after the first pressurizing pump. A third temperature detector is installed after the first pressurizing pump.

[0011] A second pressurizing pump is installed on the cold source outlet side of the water-to-water heat exchanger. A third shut-off valve and a fourth shut-off valve are installed before and after the second pressurizing pump. A fourth temperature detector is installed after the second pressurizing pump.

[0012] Furthermore, a preferred embodiment includes a waste heat recovery heat exchanger and a fifth and sixth shut-off valve located on either side of the waste heat recovery heat exchanger on the circulating water pipeline; wherein the waste heat recovery heat exchanger is connected to an external domestic hot water pipeline via a second cold source pipeline; and...

[0013] A third pressurizing pump is installed on the cold source inlet side of the waste heat utilization heat exchanger. A seventh shut-off valve and an eighth shut-off valve are installed before and after the third pressurizing pump. A fifth temperature detector is installed after the third pressurizing pump.

[0014] A fourth pressurizing pump is installed on the cold source outlet side of the waste heat utilization heat exchanger. A ninth shut-off valve and a tenth shut-off valve are installed before and after the fourth pressurizing pump. A sixth temperature detector is installed after the fourth pressurizing pump.

[0015] In addition, a preferred embodiment is to provide a first bypass corresponding to the waste heat utilization heat exchanger on the circulating water pipeline, and to provide a first shut-off valve group on the first bypass.

[0016] Furthermore, a preferred embodiment includes a heating heat exchanger and eleventh and twelfth shut-off valves located on either side of the heating heat exchanger on the circulating water pipeline; wherein the heating heat exchanger is equipped with a third cold source pipeline, and a heating radiator is installed on the third cold source pipeline; and...

[0017] A fifth pressurizing pump is installed on the cold source inlet side of the heating heat exchanger. A thirteenth shut-off valve and a fourteenth shut-off valve are installed before and after the fifth pressurizing pump. A seventh temperature detector is installed after the fifth pressurizing pump.

[0018] A sixth pressurizing pump is installed on the cold source outlet side of the heating heat exchanger. A fifteenth shut-off valve and a sixteenth shut-off valve are installed before and after the sixth pressurizing pump. An eighth temperature detector is installed after the sixth pressurizing pump.

[0019] In addition, a preferred embodiment is to provide a second bypass corresponding to the heating heat exchanger on the circulating water pipeline, and to provide a second shut-off valve assembly on the second bypass.

[0020] Furthermore, a preferred embodiment is to install a ninth temperature detector and a tenth temperature detector, respectively, on the inlet and outlet sides of the gas-water heat exchanger, on the circulating water pipeline.

[0021] In addition, a preferred embodiment is to install a water replenishment tank on the circulating water pipeline and install a water replenishment and pressure pump on the front side of the water replenishment tank.

[0022] In addition, a preferred embodiment is to install a sewage valve at the lower position of the circulating water pipeline.

[0023] On the other hand, the present invention also provides a method for using the sintering flue gas waste heat utilization system as described above, the method comprising:

[0024] A portion of the gas heat in the flue gas duct is converted into corresponding water heat in the circulating water duct through a gas-water heat exchanger, and the temperature difference in the flue gas duct is measured by a first temperature detector and a second temperature detector.

[0025] The heat in the circulating water pipeline is absorbed and utilized through water-to-water heat exchangers, waste heat utilization heat exchangers, and heating heat exchangers.

[0026] The circulating pump group controls the flow of water in the circulating water pipeline, thereby controlling the heat absorption of the flue gas pipeline by the gas-water heat exchanger, so that the temperature difference of the flue gas pipeline reaches the preset temperature reduction target value.

[0027] By utilizing the sintering flue gas waste heat utilization system and its usage method according to the present invention, the waste heat from the flue gas after the main sintering exhaust fan can be used to meet the sintering plant's year-round hot water and winter heating needs without affecting the normal operation of the main sintering process and the supporting desulfurization process. Furthermore, the amount of hot water generated by the sintering flue gas waste heat utilization system provided by the present invention (corresponding to the heat absorption of the flue gas waste heat) can vary according to changes in the sintering plant's hot water demand, exhibiting strong adaptability. Additionally, the sintering flue gas waste heat utilization system provided by the present invention can serve as a winter heating circulation branch; during the non-heating season, the heating heat exchanger can serve as a backup heat exchanger for other heat exchangers; and, all heat exchangers can be maintained without shutting down the plant.

[0028] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below and particularly pointed out in the claims. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to include all such aspects and their equivalents. Attached Figure Description

[0029] Other objects and results of the invention will become more apparent and readily understood upon reference to the following description taken in conjunction with the accompanying drawings and the contents of the claims, and with a more complete understanding of the invention. In the drawings:

[0030] Figure 1 A logic diagram of the sintering flue gas waste heat utilization system according to the present invention is shown.

[0031] Figure reference numerals: 1. Sintering main exhaust fan; 2. Desulfurization tower; 3. Gas-water heat exchanger; 6. Water-water heat exchanger; 11. Circulating pump group; 12. First temperature detector t1; 13. Second temperature detector t2; 14. Cooling tower S2; 15. First shut-off valve a15; 16. Second shut-off valve a16; 17. Third shut-off valve a17; 18. Fourth shut-off valve a18; 19. Fourth temperature detector t7; 20. Waste heat recovery heat exchanger; 11. Fifth shut-off valve a1; 12. Sixth shut-off valve a2; 13. Third shut-off valve a7; 18. Eighth shut-off valve a8; 19. Fifth temperature detector t3; 10. Fourth pressurizing pump t4; 11. Ninth shut-off valve a9, tenth shut-off valve a10, sixth temperature detector t4, first bypass 8, first shut-off valve group a3, heating heat exchanger 5, eleventh shut-off valve a4, twelfth shut-off valve a5, heating radiator S1, fifth pressurizing pump 15, thirteenth shut-off valve a13, fourteenth shut-off valve a14, seventh temperature detector t5, sixth pressurizing pump 16, fifteenth shut-off valve a11, sixteenth shut-off valve a12, eighth temperature detector t6, second bypass 9, second shut-off valve group a6, ninth temperature detector t9, tenth temperature detector t10, water supply tank 7, water supply pressurizing pump 12, sewage valve 10.

[0032] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0033] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0034] It should be noted that in the technical description of this invention, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 the invention and for simplifying the description, and do not 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 the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Figure 1 A logic diagram of the sintering flue gas waste heat utilization system according to the present invention is shown.

[0037] Depend on Figure 1 As can be seen, the sintering flue gas waste heat utilization system provided by the present invention includes a flue gas pipeline installed between the sintering main exhaust fan 1 and the desulfurization tower 2, through which the sintering flue gas enters the desulfurization tower 2 from the sintering main exhaust fan 1.

[0038] To utilize the residual heat of the sintering flue gas, a gas-water heat exchanger 3 (a heat exchange device that converts gas heat into water heat) is installed on the flue gas duct. The gas-water heat exchanger 3 is equipped with a circulating water pipeline, on which a water-water heat exchanger 6 (exchanging heat between two different water paths) and a circulating pump group 11 are installed. The circulating pump group 11 can control the flow rate of the circulating water pipeline, thereby controlling the heat exchange rate of the gas-water heat exchanger 3. Furthermore, a first temperature detector t1 and a second temperature detector t2 are installed on the flue gas duct, located on both sides of the gas-water heat exchanger 3.

[0039] In actual use, the temperature of the sintering flue gas introduced into the desulfurization tower is controlled by the heat absorption rate of the gas-water heat exchanger 3, and is detected by the first temperature detector t1 and the second temperature detector t2. The heat absorption rate of the gas-water heat exchanger 3 is controlled by the circulating pump group 11. Therefore, the circulating pump group 11 can control the temperature of the sintering flue gas introduced into the desulfurization tower 2 (corresponding to the temperature drop difference in the flue gas pipeline), so that the required temperature of the sintering flue gas in the desulfurization tower 2 is achieved. At the same time, the gas-water heat exchanger 3, in conjunction with the water-water heat exchanger 6, can convert part of the residual heat generated by the sintering flue gas into water temperature for external use.

[0040] Specifically, the water-to-water heat exchanger 6 is equipped with a first cold source pipeline, on which a cooling tower S2 is installed; and a first pressurizing pump 18 is installed on the cold source inlet side of the water-to-water heat exchanger 6, with a first shut-off valve a15 and a second shut-off valve a16 installed before and after the first pressurizing pump 18, and a third temperature detector t8 installed after the first pressurizing pump 18; a second pressurizing pump 17 is installed on the cold source outlet side of the water-to-water heat exchanger 6, with a third shut-off valve a17 and a fourth shut-off valve a18 installed before and after the second pressurizing pump 17, and a fourth temperature detector t7 installed after the second pressurizing pump 17.

[0041] For the water-to-water heat exchanger 6, by setting a cooling tower S2 in the first cold source pipeline of the water-to-water heat exchanger 6, the temperature of the circulating water pipeline can be effectively absorbed and stored for subsequent use; by setting a first pressurizing pump 18 and a second pressurizing pump 17, the flow rate of the first cold source pipeline can be controlled; by setting a first shut-off valve a15, a second shut-off valve a16, a third shut-off valve a17, and a fourth shut-off valve a18, the flow of the first cold source pipeline can be cut off in time, which facilitates the maintenance of the first pressurizing pump 18, the second pressurizing pump 17, and the cooling tower S2; by setting a third temperature detector t8 and a fourth temperature detector t7, the heat absorbed by the cooling tower S2 can be observed in time.

[0042] In addition, a waste heat utilization heat exchanger 4 can be installed to heat the domestic hot water pipeline of the entire sintering plant area. Specifically, a waste heat utilization heat exchanger 4 and a fifth shut-off valve a1 and a sixth shut-off valve a2 are installed on the circulating water pipeline. The waste heat utilization heat exchanger 4 is connected to the external domestic hot water pipeline through a second cold source pipeline. A third pressurizing pump 13 is installed on the cold source inlet side of the waste heat utilization heat exchanger 4. A seventh shut-off valve a7 and an eighth shut-off valve a8 are installed before and after the third pressurizing pump 13. A fifth temperature detector t3 is installed after the third pressurizing pump 13. A fourth pressurizing pump 14 is installed on the cold source outlet side of the waste heat utilization heat exchanger 4. A ninth shut-off valve a9 and a tenth shut-off valve a10 are installed before and after the fourth pressurizing pump 14. A sixth temperature detector t4 is installed after the fourth pressurizing pump 14.

[0043] For the waste heat recovery heat exchanger 4, the flow rate of the second cold source pipeline can be controlled by setting the third pressurizing pump 13 and the fourth pressurizing pump 14; the flow of the second cold source pipeline can be cut off in time by setting the fifth shut-off valve a1, the sixth shut-off valve a2, the seventh shut-off valve a7, the eighth shut-off valve a8, the ninth shut-off valve a9 and the tenth shut-off valve a10, which facilitates the maintenance of the third pressurizing pump 13, the fourth pressurizing pump 14 and the waste heat recovery heat exchanger 4; the heat exchange quantity of the waste heat recovery heat exchanger 4 can be observed in time by setting the fifth temperature detector t3 and the sixth temperature detector t4.

[0044] In addition, a first bypass 8 corresponding to the waste heat utilization heat exchanger 4 can be installed on the circulating water pipeline, and a first shut-off valve group a3 is installed on the first bypass; when the waste heat utilization heat exchanger 4 is shut off through the fifth shut-off valve and the sixth shut-off valve, the entire circulating water pipeline can be closed through the first bypass a3.

[0045] Alternatively, heating can be provided to the entire sintering plant area by installing a heating heat exchanger 5. Specifically, the heating heat exchanger 5 and the eleventh shut-off valve a4 and twelfth shut-off valve a5 located on both sides of the heating heat exchanger 5 can be installed on the circulating water pipeline. The heating heat exchanger 5 is equipped with a third cold source pipeline, and a heating radiator S1 is installed on the third cold source pipeline to provide heating to the entire sintering plant area. Furthermore, a fifth pressurizing pump 15 is installed on the cold source inlet side of the heating heat exchanger 5, and a thirteenth shut-off valve a13 and a fourteenth shut-off valve a14 are installed before and after the fifth pressurizing pump 15. A seventh temperature detector t5 is installed after the fifth pressurizing pump 15. A sixth pressurizing pump 16 is installed on the cold source outlet side of the heating heat exchanger 5, and a fifteenth shut-off valve a11 and a sixteenth shut-off valve a12 are installed before and after the sixth pressurizing pump 16. An eighth temperature detector t6 is installed after the sixth pressurizing pump 16.

[0046] For the heating heat exchanger 5, the flow rate of the third cold source pipeline can be controlled by setting the fifth pressurizing pump 15 and the sixth pressurizing pump 16; the flow of the third cold source pipeline can be cut off in a timely manner by setting the eleventh shut-off valve a4, the twelfth shut-off valve a5, the thirteenth shut-off valve a13, the fourteenth shut-off valve a14, the fifteenth shut-off valve a11 and the sixteenth shut-off valve a12, which facilitates the maintenance of the fifth pressurizing pump 15, the sixth pressurizing pump 16 and the heating heat exchanger 5; the heat exchange quantity of the heating heat exchanger 5 can be observed in a timely manner by setting the seventh temperature detector t5 and the eighth temperature detector t6.

[0047] In addition, a second bypass 9 corresponding to the heating heat exchanger 5 can be installed on the circulating water pipeline, and a second shut-off valve group a6 is installed on the second bypass; when the heating heat exchanger 5 is shut off by the eleventh shut-off valve a4 and the twelfth shut-off valve a5, the entire circulating water pipeline can be closed through the second bypass 9.

[0048] In addition, a ninth temperature detector t9 and a tenth temperature detector t10 can be installed on the circulating water pipeline, located on the inlet and outlet sides of the gas-water heat exchanger 3, respectively. In actual use, the heat exchange of the entire circulating water pipeline can be calculated through the ninth temperature detector t9 and the tenth temperature detector t10.

[0049] In addition, to facilitate the replenishment of water to the entire circulating water pipeline, a water replenishment tank 7 can be installed on the circulating water pipeline, and a water replenishment and pressurization pump 12 is installed in front of the water replenishment tank 7. The water replenishment and pressurization pump 12 works in conjunction with the water replenishment tank 7 to replenish water to the entire circulating water pipeline.

[0050] In addition, to facilitate the discharge of sewage from the circulating water pipeline, a sewage valve 10 can be installed at the lower position of the circulating water pipeline to discharge sewage from the circulating water pipeline.

[0051] To explain in detail the working principle of the sintering flue gas waste heat utilization system provided by the present invention, the present invention also provides a method for using the sintering flue gas waste heat utilization system, the method comprising:

[0052] A portion of the gas heat in the flue gas duct is converted into corresponding water heat in the circulating water duct through a gas-water heat exchanger, and the temperature difference in the flue gas duct is measured by a first temperature detector and a second temperature detector.

[0053] The heat in the circulating water pipes is absorbed and utilized through water-to-water heat exchangers, waste heat utilization heat exchangers, and heating heat exchangers.

[0054] By controlling the water flow in the circulating water pipeline through the circulating pump set, the heat absorption of the flue gas pipeline by the gas-water heat exchanger is controlled, so that the temperature difference of the flue gas pipeline reaches the preset temperature reduction target value.

[0055] Furthermore, the method of using the sintering flue gas waste heat utilization system provided by the present invention achieves the utilization of sintering flue gas waste heat in the following manner:

[0056] (1) Under normal operating conditions, the sintering flue gas at temperature T1 (measured by the first temperature detector) exchanges heat with the circulating water pumped by the circulating pump group through the gas-water heat exchanger. The sintering flue gas at temperature T2 (measured by the second temperature detector) after heat exchange enters the downstream desulfurization system (desulfurization tower). The temperature T2 is controlled by the circulating water volume of the circulating pump group. The system circulating water is replenished by the water replenishment tank and the water replenishment pressurization pump. The system circulating water wastewater is discharged periodically through the low-level wastewater valve.

[0057] (2) The waste heat of the sintering flue gas is transferred to the circulating water through the gas-water heat exchanger. The waste heat utilization heat exchanger heats the cold water at temperature T3 (measured by the fifth temperature detector) required by the sintering plant to temperature T4 (measured by the sixth temperature detector). The water is then returned to the sintering plant for use by the fourth pressurization pump. When there is no hot water requirement in the sintering plant, the first shut-off valve group on the first bypass is opened.

[0058] (3) When heating is required in winter, the heating circulating water at temperature T5 (measured by the seventh temperature detector) in the sintering plant area is transferred to temperature T6 (measured by the eighth temperature detector) through the heating heat exchanger and returned to the heating radiator S1 through the sixth pressurization pump 16; when there is no heating requirement, the second shut-off valve group on the second bypass is opened.

[0059] (4) The remaining heat of the circulating water system is transferred by the water-to-water heat exchanger. The circulating cooling water with temperature T7 (measured by the fourth temperature detector) is heated by the water-to-water heat exchanger 6 and then heated to temperature T8 (measured by the third detector). It is then pumped back to the cooling tower S2 by the second pressurization pump 17 for cooling and reuse.

[0060] (5) During the non-heating season, close the first shut-off valve group a6 on the second bypass 9, open the bypass of the heat exchanger to be repaired, and connect the cold side water pipe of the heat exchanger to be repaired to the cold side water pipe of the heating heat exchanger 5 to realize the repair of the heat exchanger.

[0061] The sintering flue gas waste heat utilization system and its method of use according to the present invention have been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the sintering flue gas waste heat utilization system and its method of use proposed in the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A sintering flue gas waste heat utilization system, comprising a flue gas pipeline arranged between a sintering main exhaust fan and a desulfurization tower; characterized in that, A gas-water heat exchanger is installed on the flue gas duct, and the gas-water heat exchanger is equipped with a circulating water pipeline. A water-to-water heat exchanger and a circulating pump set are installed on the circulating water pipeline. A first temperature detector and a second temperature detector are installed on the flue gas duct, located on opposite sides of the gas-water heat exchanger. The temperature of the sintering flue gas introduced into the desulfurization tower is controlled by the first temperature detector, the second temperature detector, and the circulating pump group. The water-to-water heat exchanger is equipped with a first cold source pipeline, and a cooling tower is installed on the first cold source pipeline; and... A first pressurizing pump is installed on the cold source inlet side of the water-to-water heat exchanger. A first shut-off valve and a second shut-off valve are installed before and after the first pressurizing pump. A third temperature detector is installed after the first pressurizing pump. A second booster pump is installed on the cold source outlet side of the water-to-water heat exchanger. A third and fourth shut-off valves are installed before and after the second booster pump, and a fourth temperature detector is installed after the second booster pump. A waste heat recovery heat exchanger is also installed on the circulating water pipeline, along with a fifth and sixth shut-off valve located on both sides of the waste heat recovery heat exchanger. The waste heat recovery heat exchanger is connected to an external domestic hot water pipeline via a second cold source pipeline. A third pressurizing pump is installed on the cold source inlet side of the waste heat utilization heat exchanger. A seventh shut-off valve and an eighth shut-off valve are installed before and after the third pressurizing pump. A fifth temperature detector is installed after the third pressurizing pump. A fourth pressurizing pump is installed on the cold source outlet side of the waste heat utilization heat exchanger. A ninth shut-off valve and a tenth shut-off valve are installed before and after the fourth pressurizing pump. A sixth temperature detector is installed after the fourth pressurizing pump. A first bypass corresponding to the waste heat utilization heat exchanger is provided on the circulating water pipeline, and a first shut-off valve group is provided on the first bypass. A heating heat exchanger and eleventh and twelfth shut-off valves located on the front and rear sides of the heating heat exchanger are also installed on the circulating water pipeline; wherein, the heating heat exchanger is equipped with a third cold source pipeline, and a heating radiator is installed on the third cold source pipeline; and, A fifth pressurizing pump is installed on the cold source inlet side of the heating heat exchanger. A thirteenth shut-off valve and a fourteenth shut-off valve are installed before and after the fifth pressurizing pump. A seventh temperature detector is installed after the fifth pressurizing pump. A sixth booster pump is installed on the cold source outlet side of the heating heat exchanger. A fifteenth shut-off valve and a sixteenth shut-off valve are installed before and after the sixth booster pump. An eighth temperature detector is installed after the sixth booster pump. A second bypass corresponding to the heating heat exchanger is installed on the circulating water pipeline. A second shut-off valve group is installed on the second bypass.

2. The sintering flue gas waste heat utilization system as described in claim 1, characterized in that, A ninth temperature detector and a tenth temperature detector are respectively installed on the inlet side and outlet side of the gas-water heat exchanger on the circulating water pipeline.

3. The sintering flue gas waste heat utilization system as described in claim 1, characterized in that, A water replenishment tank is installed on the circulating water pipeline, and a water replenishment and pressurization pump is installed in front of the water replenishment tank.

4. The sintering flue gas waste heat utilization system according to any one of claims 1 to 3, characterized in that, A sewage valve is installed at the lower position of the circulating water pipeline.

5. A method of using the sintering flue gas waste heat utilization system as described in any one of claims 1 to 4, characterized in that, The method includes: A portion of the gas heat in the flue gas duct is converted into corresponding water heat in the circulating water duct through a gas-water heat exchanger, and the temperature difference in the flue gas duct is measured by a first temperature detector and a second temperature detector. The heat in the circulating water pipeline is absorbed and utilized through water-to-water heat exchangers, waste heat utilization heat exchangers, and heating heat exchangers. By controlling the water flow in the circulating water pipeline through the circulating pump group, the heat absorption of the flue gas pipeline by the gas-water heat exchanger is controlled, so that the temperature difference of the flue gas pipeline reaches the preset temperature reduction index value.

Images