Blast furnace slag flushing water waste heat utilization system and its control method

Abstract

This invention discloses a blast furnace slag flushing waste heat utilization system and its control method. The system includes: a target device with an inlet and an outlet; a blast furnace with at least two slag outlets; and multiple heat exchange stations connected one-to-one with the at least two slag outlets. Each heat exchange station has a hot inlet, a hot outlet, a cold inlet, and a cold outlet. The hot inlet and the hot outlet are connected to the slag outlets. The multiple heat exchange stations are connected in series through the cold inlet and the cold outlet. The cold inlet of the heat exchange station at the beginning of the series connection is controllably connected to the outlet, and the cold outlet of the heat exchange station at the end of the series connection is controllably connected to the inlet. By connecting the heat exchange stations corresponding to the slag outlets in series, this invention ensures that heat from the slag flushing water can be continuously extracted for waste heat utilization during alternating slag discharge from the blast furnace slag outlets, while reducing the impact of slag flushing water temperature changes on the target device during alternating slag discharge.

Description

Technical Field

[0001] This invention relates to the field of blast furnace waste heat utilization technology, and in particular to a blast furnace slag flushing water waste heat utilization system and its control method. Background Technology

[0002] The steel industry generates a large amount of waste heat during production. Driven by energy conservation, emission reduction and improving corporate economic efficiency, medium and high temperature waste heat has been basically recovered. However, low temperature waste heat media are mostly ignored and wasted due to their low quality, complex composition, high impurity content, corrosiveness, poor recovery efficiency and current limitations in recovery technology and material performance. Specific examples include blast furnace slag flushing water, process circulating cooling water and industrial wastewater with a certain amount of waste heat.

[0003] From the perspective of the steel production process, blast furnace ironmaking is currently the most energy-intensive process, accounting for approximately 70% to 80% of the total energy consumption in the entire steel production process. Producing 1 ton of pig iron generates about 0.3 to 0.6 tons of blast furnace slag, with a temperature reaching 1450℃ to 1500℃. Each ton of blast furnace slag contains approximately (1.26 to 1.88) × 10⁶ kJ of sensible heat, equivalent to 0.04 to 0.06 tons of standard coal. The hydraulic slag flushing process generates flushing water at 70℃ to 90℃. This water is pressurized and cooled in a cooling tower before being reused, resulting in a significant waste of waste heat resources.

[0004] Currently, slag flushing water waste heat recovery systems recover waste heat from slag flushing water by installing waste heat recovery devices and then supply it to heating network users. However, large blast furnaces typically employ two or more slag outlets. During continuous operation, slag outlets are usually used for slag discharge, meaning that slag is discharged from one outlet while the other outlet is not in use during this period. Furthermore, the slag outlets need to be switched approximately every two hours, with a 40-minute alternation period. Consequently, the temperature of the slag flushing water at each outlet changes. The temperature of the slag flushing water in the used outlet gradually increases after the switch, while the temperature in the unused outlet gradually decreases. As a result, the temperature fluctuations of the slag flushing water caused by the alternating discharge from multiple outlets lead to temperature fluctuations at the heating network users.

[0005] Therefore, how to reduce the impact of slag water temperature changes caused by intermittent operation of slag flushing water due to slag outlet switching on the temperature fluctuations at the heating network users, while recovering and utilizing the waste heat of blast furnace slag flushing water, is a technical problem faced by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a blast furnace slag flushing water waste heat utilization system and its control method, which improves the problem of temperature fluctuation at the heating network user caused by slag outlet switching in the prior art.

[0007] The above-mentioned objectives of the present invention can be achieved by the following technical solutions:

[0008] This invention provides a blast furnace slag flushing water waste heat utilization system, comprising: a target device having an inlet and an outlet; a blast furnace having at least two slag outlets; and multiple heat exchange stations connected one-to-one with the at least two slag outlets. Each heat exchange station has a hot inlet, a hot outlet, a cold inlet, and a cold outlet. The hot inlet and the hot outlet are connected to the slag outlets. The multiple heat exchange stations are connected in series through the cold inlet and the cold outlet. The cold inlet of the heat exchange station at the beginning of the series connection is controllably connected to the outlet, and the cold outlet of the heat exchange station at the end of the series connection is controllably connected to the inlet.

[0009] Specifically, the flushing water circulates between the slag outlet and the corresponding heat exchange station, and exchanges heat in the circulating medium of the heat exchange station and the target equipment; the circulating medium of the target equipment flows through all the heat exchange stations in sequence, and exchanges heat with the flushing water in the heat exchange station corresponding to the slag outlet of the blast furnace when it is in the slag discharge state.

[0010] Furthermore, the blast furnace slag flushing water waste heat utilization system also includes a chiller, which has a driving heat source inlet, a driving heat source outlet, a target medium inlet, and a target medium outlet. The driving heat source inlet is controllably connected to the cold outlet of the heat exchange station located at the end of the series connection, the driving heat source outlet is controllably connected to the cold inlet of the heat exchange station located at the beginning of the series connection, the target medium inlet is controllably connected to the flow outlet, and the target medium outlet is controllably connected to the flow inlet.

[0011] Preferably, the blast furnace has a first slag outlet and a second slag outlet. A heat exchange station connected to the first slag outlet is a first heat exchange station, and a heat exchange station connected to the second slag outlet is a second heat exchange station. The cold inlet of the first heat exchange station is controllably connected to the outlet, the cold inlet of the second heat exchange station is connected to the cold outlet of the first heat exchange station, and the cold outlet of the second heat exchange station is controllably connected to the inlet. The target medium inlet is controllably connected to the outlet, the driving heat source inlet is controllably connected to the cold outlet of the second heat exchange station, the driving heat source outlet is controllably connected to the cold inlet of the first heat exchange station, and the target medium outlet is controllably connected to the inlet.

[0012] Preferably, the target device has a cold source demand state and a heat source demand state. In the heat source demand state, the chiller is in a closed state, the cold inlet of the first heat exchange station is connected to the outlet, and the cold outlet of the second heat exchange station is connected to the inlet. In the cold source demand state, the chiller is in a turned-on state, the target medium inlet is connected to the outlet, the driving heat source inlet is connected to the cold outlet of the second heat exchange station, the driving heat source outlet is connected to the cold inlet of the first heat exchange station, and the target medium outlet is connected to the inlet.

[0013] Preferably, an outflow pipe connects the cold inlet and the outlet of the first heat exchange station, an inflow pipe connects the cold outlet and the inflow inlet of the second heat exchange station, the target medium inlet is connected to the outflow pipe via an outflow branch pipe, the driving heat source inlet is connected to the cold outlet of the second heat exchange station via a first connecting pipe, the driving heat source outlet is connected to the outflow pipe via a second connecting pipe, and the target medium outlet is connected to the inflow pipe via an inflow branch pipe; a first cutting-off mechanism is provided on the outflow pipe between the outflow branch pipe and the second connecting pipe, a second cutting-off mechanism is provided on the inflow pipe between the inflow branch pipe and the cold outlet of the second heat exchange station, a third cutting-off mechanism is provided on the first connecting pipe, a fourth cutting-off mechanism is provided on the second connecting pipe, a fifth cutting-off mechanism is provided on the outflow branch pipe, and a sixth cutting-off mechanism is provided on the inflow branch pipe.

[0014] Preferably, the first, second, third, fourth, fifth, and sixth cutting-off mechanisms are all manually operated valves. When the target equipment is in a cold source demand state, the first and second cutting-off mechanisms are in an open state, and the third, fourth, fifth, and sixth cutting-off mechanisms are in a closed state; when the target equipment is in a heat source demand state, the first and second cutting-off mechanisms are in a closed state, and the third, fourth, fifth, and sixth cutting-off mechanisms are in an open state.

[0015] Preferably, the first, second, third, fourth, fifth, and sixth cutting-off mechanisms are all electrically operated switching valves. After acquiring the cold source demand status signal of the target equipment, the first and second cutting-off mechanisms enter the open state, and the third, fourth, fifth, and sixth cutting-off mechanisms enter the closed state; after acquiring the heat source demand status signal of the target equipment, the first and second cutting-off mechanisms enter the closed state, and the third, fourth, fifth, and sixth cutting-off mechanisms enter the open state.

[0016] Preferably, the outer walls of the outflow pipe, the inflow pipe, the outflow branch pipe, the inflow branch pipe, the first connecting pipe, and the second connecting pipe are all provided with a fire-resistant and heat-insulating material layer.

[0017] Preferably, the fire-resistant and heat-insulating material layer is a fire-resistant and heat-insulating coating applied to the outer wall of the pipe, or the fire-resistant and heat-insulating material layer is fire-resistant and heat-insulating cotton covering the outer wall of the pipe.

[0018] Another object of the present invention is to provide a control method for a blast furnace slag flushing water waste heat utilization system as described above, comprising: acquiring a demand status signal of the target equipment; sending a corresponding action signal to each electric switching valve based on the demand status signal of the target equipment; each electric switching valve performing a corresponding action based on the received action signal to enter a closed state or an open state; wherein, the demand status signal of the target equipment includes a heat source demand status signal and a cold source demand status signal, and the action signal includes a closing action signal and an opening action signal; when the acquired demand status signal of the target equipment is a cold source demand status signal, an opening action signal is sent to the first cutting-off mechanism and the second cutting-off mechanism, and a closing action signal is sent to the third cutting-off mechanism, the fourth cutting-off mechanism, the fifth cutting-off mechanism, and the sixth cutting-off mechanism; when the acquired demand status signal of the target equipment is a heat source demand status signal, a closing action signal is sent to the first cutting-off mechanism and the second cutting-off mechanism, and an opening action signal is sent to the third cutting-off mechanism, the fourth cutting-off mechanism, the fifth cutting-off mechanism, and the sixth cutting-off mechanism.

[0019] The features and advantages of this invention are as follows: The blast furnace slag flushing water waste heat utilization system provided by this invention sets up heat exchange stations connected in series with each slag outlet, so that the circulating medium of the target equipment flows through all heat exchange stations in sequence. This allows heat exchange with the blast furnace slag flushing water in the heat exchange station connected to the slag outlet when the blast furnace is in the slag discharge state. This ensures that the heat of the slag water can be continuously extracted for waste heat utilization when the blast furnace slag outlets are alternately discharging slag. At the same time, it reduces the impact of slag water temperature changes on the target equipment when the blast furnace slag outlets are alternately discharging slag, and improves the waste heat utilization rate of the blast furnace slag flushing water. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the composition of the blast furnace slag flushing water waste heat utilization system provided in the embodiment of the present invention.

[0022] Explanation of icon numbers:

[0023] 1. Blast furnace; 11. First slag outlet; 12. Second slag outlet;

[0024] 2. First heat exchange station;

[0025] 3. Second heat exchange station;

[0026] 4. Target equipment;

[0027] 5. Refrigeration unit;

[0028] 10. Outflow pipe;

[0029] 20. Inflow into the pipeline;

[0030] 30. Outflow branch pipe;

[0031] 40. First connecting pipe;

[0032] 50. Second connecting pipe;

[0033] 60. Flowing into the branch pipe;

[0034] K1, First cutting mechanism;

[0035] K2, Second Cutting Mechanism;

[0036] K3, the third cutting mechanism;

[0037] K4, the fourth cutting mechanism;

[0038] K5, the fifth cutting mechanism;

[0039] K6, the sixth cutting mechanism. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] like Figure 1 As shown, this invention provides a blast furnace slag flushing water waste heat utilization system, including a blast furnace 1, a heat exchange station, and a target device 4. The heat exchange station is connected between the blast furnace 1 and the target device 4. The target device 4 has an inlet and an outlet. The blast furnace 1 has at least two slag outlets. Multiple heat exchange stations are connected to each of the at least two slag outlets. Each heat exchange station has a hot inlet, a hot outlet, a cold inlet, and a cold outlet. The hot inlet and hot outlet are connected to the slag outlets. Multiple heat exchange stations are connected in series via cold inlets and cold outlets. That is, from the beginning to the end of the series connection, the cold outlet of the preceding heat exchange station is connected to the cold inlet of the following heat exchange station. The cold inlet of the heat exchange station at the beginning of the series connection is controllably connected to the outlet, and the cold outlet of the heat exchange station at the end of the series connection is controllably connected to the inlet. Specifically, the blast furnace flushing water circulates between the slag outlet and the corresponding heat exchange station. After exchanging heat and cooling in the heat exchange station and the circulating medium of target device 4, it returns to the flushing outlet for the next flushing cycle. The circulating medium of target device 4 flows sequentially through multiple heat exchange stations connected in series. In the heat exchange station corresponding to the slag outlet of blast furnace 1 at the current slag discharge stage, it exchanges heat with the blast furnace flushing water and heats up before returning to target device 4. In this way, the waste heat of the flushing water is used to heat the circulating medium of target device 4, thereby supplying heat to users. Preferably, the heat exchange station is equipped with at least one plate heat exchanger. Specifically, blast furnace slag flushing water flows into the hot inlet of the plate heat exchanger through the slag water outlet pipe 10, and the circulating medium of the target device 4 flows into the cold inlet of the plate heat exchanger. After the two exchange heat in the plate heat exchanger, the blast furnace slag flushing water returns to the slag flushing port from the hot outlet of the plate heat exchanger through the slag water return pipe, and the circulating medium of the target device 4 returns to the target device 4 from the cold outlet of the plate heat exchanger. This cycle is repeated to realize the utilization of waste heat from blast furnace slag flushing water.

[0042] The target device 4 can be a multi-attribute device with both cold source demand and heat source demand states, or a single-attribute device with only either a cold source demand state or a heat source demand state. When the target device 4 is in a heat source demand state, the waste heat obtained by the heat exchange station is directly supplied to the target device 4. When the target device 4 is in a cold source demand state, the waste heat obtained by the heat exchange station can be used as the driving heat source to drive the operation of the chiller 5, and the cold source produced by the operation of the chiller 5 can be supplied to the target device 4, thereby realizing the full utilization of the waste heat of the blast furnace slag flushing water.

[0043] The blast furnace slag flushing water waste heat utilization system provided by the present invention sets up heat exchange stations connected in series with each slag outlet, so that the circulating medium of the target device 4 flows through all heat exchange stations in sequence. This allows the heat exchange station connected to the slag outlet of the blast furnace 1 at the time of slag discharge to exchange heat with the blast furnace slag flushing water. This ensures that the heat of the slag water can be continuously extracted for waste heat utilization when the blast furnace 1 slag outlets are alternately discharging slag. At the same time, it reduces the impact of slag water temperature changes on the target device 4 when the blast furnace 1 slag outlets are alternately discharging slag, and improves the waste heat utilization rate of the blast furnace slag flushing water.

[0044] According to a preferred embodiment of the present invention, such as Figure 1 As shown, the blast furnace slag flushing water waste heat utilization system also includes a chiller 5. The chiller 5 has a driving heat source inlet, a driving heat source outlet, a target medium inlet, and a target medium outlet. The driving heat source inlet is controllably connected to the cold outlet of the heat exchange station located at the end of the series connection, and the driving heat source outlet is controllably connected to the cold inlet of the heat exchange station located at the beginning of the series connection. The target medium inlet is controllably connected to the flow outlet, and the target medium outlet is controllably connected to the flow inlet. By setting up the chiller 5 and selectively diverting the heat extracted from the slag water to the chiller 5 as a driving heat source, the chiller 5 produces a low-temperature target medium, i.e., a cold source, which is then supplied to users. Thus, through the selective connection of the chiller 5, the blast furnace slag flushing water waste heat utilization system provided by this invention has a combined cooling and heating function, thereby meeting the user's summer cooling and winter heating needs. The chiller 5 can be a single unit or multiple units can be configured as needed; this application does not impose any restrictions on this.

[0045] According to one embodiment of the present invention, a blast furnace 1 has a first slag outlet 11 and a second slag outlet 12. A heat exchange station connected to the first slag outlet 11 is a first heat exchange station 2, and a heat exchange station connected to the second slag outlet 12 is a second heat exchange station 3. The cold inlet and outlet of the first heat exchange station 2 are controllably connected, the cold inlet of the second heat exchange station 3 is connected to the cold outlet of the first heat exchange station 2, and the cold outlet of the second heat exchange station 3 is controllably connected to the inlet. The inlet of the target medium is controllably connected to the outlet, the inlet of the driving heat source is controllably connected to the cold outlet of the second heat exchange station 3, the outlet of the driving heat source is controllably connected to the cold inlet of the first heat exchange station 2, and the outlet of the target medium is controllably connected to the inlet.

[0046] Specifically, such as Figure 1 As shown, the first heat exchange station 2 is located near the first slag outlet 11, and the second heat exchange station 3 is located near the second slag outlet 12, in order to shorten the circulation process of the flushing water as much as possible and to take into account the special properties of the slag water. In summer, the heat extracted from the slag water by the heat exchange stations is diverted to the chiller 5 as a driving heat source to drive the chiller 5 to work and produce a cold source for users to use for cooling; in winter, the heat extracted from the slag water by the heat exchange stations is directly delivered to users to provide them with heating.

[0047] According to one embodiment of the present invention, the target device 4 has a cold source demand state and a heat source demand state. In the heat source demand state, the chiller 5 is in the off state, the cold inlet of the first heat exchange station 2 is connected to the outlet, and the cold outlet of the second heat exchange station 3 is connected to the inlet. The heat extracted from the sludge by the heat exchange stations is directly sent to the target device 4 for use. In the cold source demand state, the chiller 5 is in the on state, the target medium inlet is connected to the outlet, the driving heat source inlet is connected to the cold outlet of the second heat exchange station 3, the driving heat source outlet is connected to the cold inlet of the first heat exchange station 2, and the target medium outlet is connected to the inlet. The heat extracted from the sludge by the heat exchange stations is used to drive the chiller 5 to work and deliver the cold source to the target device 4 for use.

[0048] Specifically, under heat source demand conditions, after the target equipment 4 at the user's location completes heat exchange, it produces heating water return water. This heating water return water absorbs heat sequentially through the first heat exchange station 2 and the second heat exchange station 3, raising its temperature to form heating water supply water, which is then sent to the user for heating use. After heat exchange, the heating water return water returns to the first heat exchange station 2, thus completing one heat source cycle. Under cold source demand conditions, the driving heat source water return water on the hot side of the chiller 5 absorbs heat sequentially through the first heat exchange station 2 and the second heat exchange station 3, raising its temperature to form driving heat source water, which is then sent to the chiller 5 to drive its operation. After use, the driving heat source water return water returns to the first heat exchange station 2, thus completing one chiller 5 hot-side cycle. The chilled water produced by the chiller 5 is sent to the target equipment 4 at the user's location for heat exchange, forming chilled water return water, which is then sent back to the chiller 5, thus completing one chiller 5 cold-side cycle. That is, the driving heat source water serves as an intermediate medium between the heat exchange station and the chiller 5, carrying the heat from the slag water obtained by the heat exchange station to the chiller 5 and finally converting it for application in the target equipment 4.

[0049] According to one embodiment of the present invention, such as Figure 1 As shown, an outflow pipe 10 connects the cold inlet and outlet of the first heat exchange station 2, and an inflow pipe 20 connects the cold outlet and inlet of the second heat exchange station 3. The target medium inlet is connected to the outflow pipe 10 through an outflow branch pipe 30. The driving heat source inlet is connected to the cold outlet of the second heat exchange station 3 through a first connecting pipe 40, and the driving heat source outlet is connected to the outflow pipe 10 through a second connecting pipe 50. The target medium outlet is connected to the inflow pipe 20 through an inflow branch pipe 60. A first cutting-off mechanism K1 is provided on the outflow pipe 10 between the outflow branch pipe 30 and the second connecting pipe 50. A second cutting-off mechanism K2 is provided on the inflow pipe 20 between the inflow branch pipe 60 and the cold outlet of the second heat exchange station 3. A third cutting-off mechanism K3 is provided on the first connecting pipe 40. A fourth cutting-off mechanism K4 is provided on the second connecting pipe 50. A fifth cutting-off mechanism K5 is provided on the outflow branch pipe 30, and a sixth cutting-off mechanism K6 is provided on the inflow branch pipe 60. By installing a shut-off mechanism on the corresponding pipeline, the switching control between cooling and heating outputs of the blast furnace slag flushing water waste heat utilization system can be achieved. Furthermore, by leading an inflow branch pipe 60 from the inflow pipe 20 to the target medium outlet and an outflow branch pipe 30 from the outflow pipe 10 to the target medium inlet, system optimization and investment savings are achieved.

[0050] According to one embodiment of the present invention, the first cutting-off mechanism K1, the second cutting-off mechanism K2, the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 are all manually operated valves. When the target device 4 is in a cold source demand state, the first cutting-off mechanism K1 and the second cutting-off mechanism K2 are in an open state, while the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 are in a closed state. When the target device 4 is in a heat source demand state, the first cutting-off mechanism K1 and the second cutting-off mechanism K2 are in a closed state, while the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 are in an open state. By setting the first cutting-off mechanism K1, the second cutting-off mechanism K2, the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 as manually operated valves, the switching control requirements for summer cooling output and winter heating output can be met while saving costs and energy consumption.

[0051] According to one embodiment of the present invention, the first cutting-off mechanism K1, the second cutting-off mechanism K2, the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 are all electrically operated switching valves. After acquiring the cold source demand status signal of the target device 4, the first cutting-off mechanism K1 and the second cutting-off mechanism K2 enter the open state, and the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 enter the closed state. After acquiring the heat source demand status signal of the target device 4, the first cutting-off mechanism K1 and the second cutting-off mechanism K2 enter the closed state, and the third cutting-off mechanism K3, the fourth cutting-off mechanism K4, the fifth cutting-off mechanism K5, and the sixth cutting-off mechanism K6 enter the open state. This facilitates real-time and rapid switching control response between cooling output and heating output according to the usage requirements of the target device 4.

[0052] According to one embodiment of the present invention, the outer walls of the outflow pipe 10, inflow pipe 20, outflow branch pipe 30, inflow branch pipe 60, first connecting pipe 40, and second connecting pipe 50 are all provided with a refractory insulation material layer. By providing a refractory insulation material layer on the outside of the connecting pipes, the heat exchange between the medium inside the pipe and the external environment is reduced, further improving the efficiency of waste heat utilization of slag and water.

[0053] According to one embodiment of the present invention, the fire-resistant and heat-insulating material layer is a fire-resistant and heat-insulating coating applied to the outer wall of the pipe.

[0054] According to one embodiment of the present invention, the fire-resistant insulation material layer is fire-resistant insulation cotton covering the outer wall of the pipe.

[0055] This invention also provides a control method applied to the above-mentioned blast furnace slag flushing water waste heat utilization system, comprising: acquiring a demand status signal of the target equipment; sending a corresponding action signal to each electric switching valve based on the demand status signal of the target equipment; each electric switching valve performing a corresponding action based on the received action signal to enter a closed state or an open state; wherein, the demand status signal of the target equipment includes a heat source demand status signal and a cold source demand status signal, and the action signal includes a closing action signal and an opening action signal; when the acquired demand status signal of the target equipment is a cold source demand status signal, an opening action signal is sent to the first cutting-off mechanism and the second cutting-off mechanism, and a closing action signal is sent to the third cutting-off mechanism, the fourth cutting-off mechanism, the fifth cutting-off mechanism, and the sixth cutting-off mechanism; when the acquired demand status signal of the target equipment is a heat source demand status signal, a closing action signal is sent to the first cutting-off mechanism and the second cutting-off mechanism, and an opening action signal is sent to the third cutting-off mechanism, the fourth cutting-off mechanism, the fifth cutting-off mechanism, and the sixth cutting-off mechanism.

[0056] Specifically, the blast furnace slag flushing water waste heat utilization system also includes a controller. The controller is electrically connected to the target equipment and each electric switching valve. The controller receives the demand status signal of the target equipment and sends corresponding action signals to each electric switching valve, so that each electric switching valve performs the corresponding action. Thus, based on the usage requirements of the target equipment 4, a closed-loop control of cooling output and heating output is realized, which not only improves the waste heat utilization rate of slag flushing water, but also meets the needs of the target equipment.

[0057] Based on the above description, the blast furnace slag flushing water waste heat utilization system provided in the embodiments of the present invention has the following beneficial effects:

[0058] The blast furnace slag flushing water waste heat utilization system provided in this embodiment of the invention connects heat exchange stations connected in series with each slag outlet to continuously extract heat from the slag water for waste heat utilization during alternating slag discharge from the blast furnace 1 slag outlet. This reduces the impact of slag water temperature changes during alternating slag discharge from the blast furnace 1 slag outlet on the target equipment 4 and improves the waste heat utilization rate of the blast furnace slag flushing water. Furthermore, through the selective connection of the chiller 5, the blast furnace slag flushing water waste heat utilization system provided in this invention has a combined cooling and heating function, thereby meeting the user's summer cooling and winter heating needs.

[0059] The above descriptions are merely a few embodiments of the present invention. Those skilled in the art can make various modifications or variations to the embodiments of the present invention based on the content disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A blast furnace slag flushing water waste heat utilization system, characterized in that, include: Target equipment having an inlet and an outlet; A blast furnace with at least two slag outlets; Multiple heat exchange stations are connected in a one-to-one correspondence with at least two of the slag outlets. Each heat exchange station has a hot inlet, a hot outlet, a cold inlet, and a cold outlet. The hot inlet and the hot outlet are connected to the slag outlets. The multiple heat exchange stations are connected in series through the cold inlet and the cold outlet. The cold inlet of the heat exchange station at the beginning of the series is controllably connected to the outlet, and the cold outlet of the heat exchange station at the end of the series is controllably connected to the inlet.

2. The blast furnace slag flushing water waste heat utilization system according to claim 1, characterized in that, The blast furnace slag flushing water waste heat utilization system also includes a chiller, which has a driving heat source inlet, a driving heat source outlet, a target medium inlet, and a target medium outlet. The driving heat source inlet is controllably connected to the cold outlet of the heat exchange station located at the end of the series connection, the driving heat source outlet is controllably connected to the cold inlet of the heat exchange station located at the beginning of the series connection, the target medium inlet is controllably connected to the flow outlet, and the target medium outlet is controllably connected to the flow inlet.

3. The blast furnace slag flushing water waste heat utilization system according to claim 2, characterized in that, The blast furnace has a first slag outlet and a second slag outlet. A heat exchange station connected to the first slag outlet is a first heat exchange station, and a heat exchange station connected to the second slag outlet is a second heat exchange station. The cold inlet of the first heat exchange station is controllably connected to the outlet, the cold inlet of the second heat exchange station is connected to the cold outlet of the first heat exchange station, and the cold outlet of the second heat exchange station is controllably connected to the inlet. The target medium inlet is controllably connected to the outlet, the driving heat source inlet is controllably connected to the cold outlet of the second heat exchange station, the driving heat source outlet is controllably connected to the cold inlet of the first heat exchange station, and the target medium outlet is controllably connected to the inlet.

4. The blast furnace slag flushing water waste heat utilization system according to claim 3, characterized in that, The target equipment has a cold source demand state and a heat source demand state. In the heat source demand state, the chiller is in the off state, the cold inlet of the first heat exchange station is connected to the outlet, and the cold outlet of the second heat exchange station is connected to the inlet. In the cold source demand state, the chiller is in the on state, the target medium inlet is connected to the outlet, the driving heat source inlet is connected to the cold outlet of the second heat exchange station, the driving heat source outlet is connected to the cold inlet of the first heat exchange station, and the target medium outlet is connected to the inlet.

5. The blast furnace slag flushing water waste heat utilization system according to claim 4, characterized in that, An outflow pipe connects the cold inlet and the outlet of the first heat exchange station, and an inflow pipe connects the cold outlet and the inlet of the second heat exchange station. The target medium inlet is connected to the outflow pipe via an outflow branch pipe. The driving heat source inlet is connected to the cold outlet of the second heat exchange station via a first connecting pipe, and the driving heat source outlet is connected to the outflow pipe via a second connecting pipe. The target medium outlet is connected to the inflow pipe via an inflow branch pipe. A first cutting-off mechanism is provided on the outflow pipe between the outflow branch pipe and the second connecting pipe. A second cutting-off mechanism is provided on the inflow pipe between the inflow branch pipe and the cold outlet of the second heat exchange station. A third cutting-off mechanism is provided on the first connecting pipe, a fourth cutting-off mechanism is provided on the second connecting pipe, a fifth cutting-off mechanism is provided on the outflow branch pipe, and a sixth cutting-off mechanism is provided on the inflow branch pipe.

6. The blast furnace slag flushing water waste heat utilization system according to claim 5, characterized in that, The first, second, third, fourth, fifth, and sixth cutting-off mechanisms are all manually operated on / off valves. When the target equipment is in a cold source demand state, the first and second cutting-off mechanisms are in an open state, and the third, fourth, fifth, and sixth cutting-off mechanisms are in a closed state. When the target equipment is in a heat source demand state, the first and second cutting-off mechanisms are in a closed state, and the third, fourth, fifth, and sixth cutting-off mechanisms are in an open state.

7. The blast furnace slag flushing water waste heat utilization system according to claim 5, characterized in that, The first, second, third, fourth, fifth, and sixth cutting-off mechanisms are all electrically operated switching valves. After acquiring the cold source demand status signal of the target equipment, the first and second cutting-off mechanisms enter the open state, and the third, fourth, fifth, and sixth cutting-off mechanisms enter the closed state. After acquiring the heat source demand status signal of the target equipment, the first and second cutting-off mechanisms enter the closed state, and the third, fourth, fifth, and sixth cutting-off mechanisms enter the open state.

8. The blast furnace slag flushing water waste heat utilization system according to claim 5, characterized in that, The outer walls of the outflow pipe, the inflow pipe, the outflow branch pipe, the inflow branch pipe, the first connecting pipe, and the second connecting pipe are all provided with a fire-resistant and heat-insulating material layer.

9. The blast furnace slag flushing water waste heat utilization system according to claim 8, characterized in that, The fire-resistant and heat-insulating material layer is a fire-resistant and heat-insulating coating applied to the outer wall of the pipe, or the fire-resistant and heat-insulating material layer is fire-resistant and heat-insulating cotton covering the outer wall of the pipe.

10. The blast furnace slag flushing water waste heat utilization system according to claim 1, characterized in that, The flushing water circulates between the slag outlet and the corresponding heat exchange station, and exchanges heat with the circulating medium of the heat exchange station and the target equipment. The circulating medium of the target equipment flows through all the heat exchange stations in sequence, and exchanges heat with the flushing water in the heat exchange station corresponding to the slag outlet of the blast furnace when it is in the slag discharge state.

11. A control method applied to the blast furnace slag flushing water waste heat utilization system as described in claim 7, characterized in that, include: Obtain the demand status signal of the target device; Based on the demand status signal of the target device, send corresponding action signals to each electric switching valve; Each electrically operated valve performs a corresponding action based on the received action signal, entering either a closed or open state. The target device's demand status signal includes a heat source demand status signal and a cold source demand status signal. The action signal includes a closing action signal and a closing action signal. When the target device's demand status signal is a cold source demand status signal, a closing action signal is sent to the first cutting mechanism and the second cutting mechanism, and a closing action signal is sent to the third cutting mechanism, the fourth cutting mechanism, the fifth cutting mechanism, and the sixth cutting mechanism. When the target device's demand status signal is a heat source demand status signal, a closing action signal is sent to the first cutting mechanism and the second cutting mechanism, and a closing action signal is sent to the third cutting mechanism, the fourth cutting mechanism, the fifth cutting mechanism, and the sixth cutting mechanism.

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