Industrial kiln wide temperature range waste heat stable steam generating device and process thereof

Abstract

This invention discloses a wide-temperature-range waste heat stabilization steam generation device and its process for industrial kilns, comprising: a heat extraction circulation component for heat extraction from a heat source, having a liquid circulation medium capable of being vaporized by heat extraction and a gas channel for conveying the gaseous circulation medium; and a buffer circulation component connected to the heat extraction circulation component, capable of exchanging heat with the liquid circulation medium within the heat extraction circulation component, and connected to a circulation medium source to replenish the liquid circulation medium. The process can store some heat when the heat extraction load is high and release some heat when the heat extraction load is low, thereby stabilizing steam generation over a wide temperature range. This invention has applications in the field of waste heat utilization.

Description

Technical Field

[0001] This invention relates to the field of waste heat utilization, and in particular to a device for stabilizing steam generation from waste heat in industrial kilns over a wide temperature range. Background Technology

[0002] In industrial kilns with internal temperatures exceeding 600℃, such as graphitization furnaces, carbon furnaces, calcining furnaces, pre-carbonization kilns, ceramic kilns, and aluminum alloy melting furnaces, there is a high-temperature cooling process for finished products or waste residue. This cooling process is characterized by periodic occurrence, high initial temperature, rapid heat extraction rate, and high heat extraction pressure, followed by low temperature, slow heat extraction rate, continuous load decrease, and a wide temperature range throughout the process. Currently, the utilization of waste heat from high-temperature kilns in various industries mainly focuses on the stable utilization of waste heat, or only utilizes waste heat from the high-temperature stage. The utilization of waste heat from the low-temperature stage, which constitutes the majority of the cooling process in the aforementioned processes, is relatively low. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a wide-temperature-range waste heat stabilization steam generation device for industrial kilns, which can stably generate steam within a wide temperature range using waste heat.

[0004] A process for stabilizing steam production from waste heat in an industrial kiln using the aforementioned wide-temperature-range waste heat stabilization steam production device is also proposed.

[0005] An industrial kiln wide-temperature-range waste heat stabilization steam generation device according to a first aspect embodiment of the present invention includes:

[0006] A heat extraction circulation assembly for extracting heat from a heat source, having a liquid circulation medium capable of being vaporized by heat extraction and a gas channel for conveying the gaseous circulation medium;

[0007] The buffer circulation component is connected to the heat extraction circulation component and can exchange heat with the liquid circulation medium in the heat extraction circulation component. It can also be connected to the circulation medium source to replenish the liquid circulation medium.

[0008] The industrial kiln wide-temperature-range waste heat stabilization steam generation device according to the first aspect of the present invention has at least the following beneficial effects:

[0009] 1. In the initial stage when the kiln temperature is high, the heat extraction circulation component extracts heat. After heat extraction, part of the liquid circulation medium vaporizes into a gaseous state. The high-temperature gaseous circulation medium then flows through the gas channel into other devices that can utilize heat energy, where the heat from the gaseous circulation medium is utilized. After heat extraction, some liquid circulation medium still contains heat. This heat-containing liquid circulation medium is exchanged through a buffer circulation component. The buffer circulation component is replenished with an equal amount of liquid circulation medium to the vaporized circulation medium through a circulation medium source, thus maintaining the temperature of the liquid circulation medium in the heat extraction circulation component. Compared to the initial temperature of the liquid circulating medium to be heated, the temperature rises slowly. Consequently, during each heat extraction cycle, the temperature of the liquid circulating medium rises slowly with minimal temperature difference changes. Ultimately, under the same heat extraction load, the temperature change of the liquid circulating medium to be heated is small, making it convenient to control its overall vaporization rate by controlling the heat extraction flow rate. This achieves the goal of avoiding excessive vaporization of the liquid circulating medium in the initial stage when the kiln temperature is high, and enabling a continuous output of a stable flow rate of gaseous circulating medium to other external devices that can utilize thermal energy.

[0010] 2. When the kiln temperature drops to a point where the heat available to the heat extraction circulation component decreases, the reduced heat extraction hinders the vaporization of the liquid circulating medium at normal temperature, leading to a decrease in the vaporization rate of the liquid circulating medium. However, when using the circulating medium that has passed through the high-temperature stage of the kiln for heat extraction, the buffer circulation component no longer replenishes the liquid circulating medium through the circulating medium source. At the same time, the buffer circulation component no longer exchanges heat with the heat extraction circulation component. The buffer circulation component only inputs the circulating medium into the heat extraction circulation component, allowing the overall temperature of the liquid circulating medium in both the buffer circulation component and the heat extraction circulation component to remain at the increased state. The heat extraction load required for the vaporization of the increased-temperature circulating medium decreases, and the liquid circulating medium can still maintain a certain vaporization rate and be output through the gas channel. This achieves the goal of avoiding insufficient vaporization of the liquid circulating medium in the later stages when the kiln temperature is low, and continuously outputting a stable flow rate of gaseous circulating medium to other external devices that can utilize thermal energy.

[0011] 3. It can stably provide gaseous circulating medium in a wide temperature range, from high temperature in the early stage to low temperature in the later stage of the kiln. Its temperature range is more applicable, and it is especially suitable for situations where there is a large temperature difference when the kiln dissipates heat.

[0012] According to some embodiments of the present invention, the buffer loop component includes:

[0013] Buffer storage;

[0014] The first buffer pipe connects the buffer storage unit and the heat extraction circulation assembly, and is capable of delivering the liquid circulation medium into the heat extraction circulation assembly;

[0015] The second buffer pipe connects the buffer storage unit and the heat extraction circulation assembly, and is capable of delivering the liquid circulation medium into the buffer storage unit.

[0016] According to some embodiments of the present invention, the buffer circulation component can be connected to the circulation medium source via a preprocessing component, the preprocessing component being used to preprocess the circulation medium.

[0017] According to some embodiments of the present invention, the heat extraction circulation assembly includes:

[0018] The medium storage unit has the gas passage connected to it and is connected to the buffer circulation assembly;

[0019] The heat extraction pipeline forms a circulation loop with the medium storage container, enabling it to transport the circulating medium and connect to an external heat source for heat conduction.

[0020] According to some embodiments of the present invention, the medium storage device is provided with a gas-liquid separator.

[0021] According to the second aspect of the present invention, the industrial kiln wide-temperature-range waste heat stabilization steam generation process uses the industrial kiln wide-temperature-range waste heat stabilization steam generation device described in the first aspect of the present invention.

[0022] The industrial kiln wide-temperature-range waste heat stable steam generation process according to the second aspect of the present invention has at least the following beneficial effects: it can make the vaporization rate of the circulating medium in the heat extraction circulation component more stable, facilitate stable steam output, and adapt to a wider temperature range, thereby improving the applicability.

[0023] According to some embodiments of the present invention, the heat extraction vaporization rate of the liquid circulating medium in the heat extraction circulation component is controlled to be lower than a preset value.

[0024] According to some embodiments of the present invention, the flow rate of the liquid circulating medium to be heated in the heat extraction circulation assembly is adjusted according to the temperature of the heat source, the flow rate of the gas channel, and the flow rate of the liquid circulating medium to be heated in the heat extraction circulation assembly, so as to drive a dynamic balance between the flow rate of the liquid circulating medium to be heated and the flow rate of the gas circulating medium.

[0025] The buffer circulation component replenishes liquid circulation medium from the circulation medium source and adds a liquid circulation medium flow rate equal to the flow rate of the vaporized circulation medium to the heat extraction circulation component.

[0026] According to some embodiments of the present invention, multiple cooling stages are divided according to the ratio range of the heat extraction load to the system design output load X. In different cooling stages, the buffer circulation component controls the temperature of the liquid circulating medium to be extracted within the heat extraction circulation component within a preset range.

[0027] According to some embodiments of the present invention, there are two cooling stages: a high-speed cooling stage corresponding to the high temperature of the heat source and a low-speed cooling stage corresponding to the low temperature of the heat source.

[0028] If X is within the ratio range corresponding to the high-speed cooling stage, the buffer circulation component and the heat extraction circulation component undergo liquid circulation medium heat exchange circulation. The flow rate of the buffer circulation component into the heat extraction circulation component is adjusted according to the flow rate of the gas channel and the flow rate of the liquid circulation medium input into the buffer circulation component by the heat extraction circulation component.

[0029] If X is within the ratio range corresponding to the low-speed cooling stage, the buffer circulation component stops replenishing liquid circulation medium from the circulation medium source, the buffer circulation component continues to supply circulation medium to the heat extraction circulation component, and the liquid circulation medium heat exchange circulation between the heat extraction circulation components is reduced to the minimum or shut down until the liquid level of the liquid circulation medium in the buffer circulation component drops to the minimum, and then the liquid circulation medium is replenished to the buffer circulation component again.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0032] Figure 1 This is a schematic diagram of the structure of an industrial kiln wide-temperature-range waste heat stabilization steam generation device according to an embodiment of the present invention;

[0033] Figure 2 This is a control principle diagram of the buffer water tank in the wide temperature range waste heat stabilization steam generation process of an industrial kiln according to an embodiment of the present invention, at different cooling stages.

[0034] Figure 3 This is a control principle diagram of the circulating pump in a wide-temperature-range waste heat stabilization steam generation process of an industrial kiln according to an embodiment of the present invention, at different cooling stages.

[0035] Figure 4 This is a schematic diagram of the structure of a wide-temperature-range waste heat stabilization steam generation process for an industrial kiln according to an embodiment of the present invention, showing the control principle of the buffer water pump at different cooling stages.

[0036] Icon labels:

[0037] Heat extraction circulation component 100; gas passage 110; medium storage container 120; heat extraction pipeline 130; buffer circulation component 200; buffer storage container 210; first buffer pipeline 220; first valve 221; second buffer pipeline 230; second valve 222; pretreatment component 240; heat source 300; temperature detection component 310; circulating medium source 400. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 limiting this invention.

[0040] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or the order in which the indicated technical features are presented.

[0041] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0042] Reference Figures 1 to 4 As shown, an embodiment of the present invention provides a wide-temperature-range waste heat stabilization steam generation device for industrial kilns, comprising:

[0043] The heat extraction circulation assembly 100 is used to extract heat from the heat source 300, and has a liquid circulation medium that can be vaporized by heat extraction and a gas channel 110 for conveying the gaseous circulation medium.

[0044] The buffer circulation component 200 is connected to the heat extraction circulation component 100 and can exchange heat with the liquid circulation medium inside the heat extraction circulation component 100. It can also be connected to the circulation medium source 400 to replenish the liquid circulation medium.

[0045] It is understandable that in the initial stage when the kiln temperature is high, heat is extracted through the heat extraction circulation component 100. After heat extraction, part of the liquid circulation medium vaporizes into a gaseous state. The high-temperature gaseous circulation medium will enter other devices that can utilize heat energy through the gas channel 110, where the heat of the gaseous circulation medium is utilized. After heat extraction, some liquid circulation medium still contains some heat. The buffer circulation component 200 exchanges heat with the liquid circulation medium containing heat. The buffer circulation component 200 is replenished with an equal amount of liquid circulation medium to the vaporized circulation medium through the circulation medium source 400, so that the heat extraction circulation component... The temperature of the liquid circulating medium in component 100 rises slowly compared to the initial temperature of the liquid circulating medium to be heated. Consequently, during each heat extraction process, the temperature of the liquid circulating medium that has undergone multiple heat extraction cycles rises slowly, with minimal temperature difference changes. Ultimately, when the heat extraction load is the same, the temperature change of the liquid circulating medium to be heated is small, making it convenient to control its overall vaporization rate by controlling the heat extraction flow rate of the liquid circulating medium to be heated. This achieves the goal of avoiding excessive vaporization of the liquid circulating medium in the initial stage when the kiln temperature is high, and enabling the continuous output of a stable flow rate of gaseous circulating medium to other external devices that can utilize thermal energy.

[0046] Other devices that can utilize thermal energy may be boilers or steam power generation equipment, or multiple devices that share thermal energy through a steam network.

[0047] It is understandable that when the kiln temperature drops to the point where the heat that the heat recovery circulation component 100 can obtain decreases, the reduced heat recovery is not conducive to the vaporization of the liquid circulating medium at normal temperature, resulting in a decrease in the vaporization rate of the liquid circulating medium. However, when using the circulating medium that has passed through the high-temperature stage of the kiln for heat recovery, the buffer circulation component 200 no longer replenishes the liquid circulating medium through the circulating medium source 400. At the same time, the buffer circulation component 200 no longer exchanges heat with the heat recovery circulation component 100. The buffer circulation component 200 only inputs the circulating medium into the heat recovery circulation component, so that the overall temperature of the liquid circulating medium in the buffer circulation component 200 and the heat recovery circulation component 100 can be maintained at the increased state. The heat recovery load required for the vaporization of the increased temperature circulating medium is reduced, and the liquid circulating medium can still maintain a certain vaporization rate and be output through the gas channel 110. This achieves the goal of avoiding insufficient vaporization of the liquid circulating medium in the later stage when the kiln temperature is low, and continuously outputting a stable flow rate of gaseous circulating medium to other external devices that can utilize heat energy.

[0048] It can stably provide gaseous circulating medium in a wide temperature range, from high temperature in the early stage to low temperature in the later stage of the kiln. Its temperature range is more applicable, and it is especially suitable for situations where there is a large temperature difference when the kiln is dissipating heat.

[0049] Reference Figure 1 As shown, the buffer loop component 200 includes:

[0050] Buffer storage component 210;

[0051] The first buffer pipe 220 connects the buffer storage 210 and the heat extraction circulation component 100, and can transport liquid circulation medium into the heat extraction circulation component 100.

[0052] The second buffer pipe 230 connects the buffer storage unit 210 and the heat extraction circulation component 100, and can transport liquid circulating medium into the buffer storage unit 210.

[0053] It is understandable that the buffer storage unit 210, through the first buffer pipe 220, transports the circulating medium replenished by the circulating medium source 400 to the heat-extracting circulation component 100, causing the ambient temperature circulating medium provided by the circulating medium source 400 to mix with the higher temperature circulating medium in the heat-extracting circulation component 100, thus lowering the temperature of the circulating medium in the heat-extracting circulation component 100. The heat-extracting circulation component 100, through the second buffer pipe 230, transports the higher temperature circulating medium to the buffer component, where it mixes with the ambient temperature circulating medium replenished in the buffer storage unit 210, thus raising the temperature of the circulating medium in the buffer storage unit 210. At high temperatures in the kiln, this facilitates heat exchange between the heat-extracting circulation component 100 and the buffer circulation component 200, enabling stable control of the vaporization rate of the liquid circulating medium. When the kiln is at a low temperature, the buffer circulation component 200 stores the excess heat from the high temperature of the kiln. When the kiln is at a low temperature, the stored heat is used to facilitate the vaporization of the liquid circulation medium, so as to balance the heat load of the kiln at high and low temperatures. The excess heat at high temperature is stored for use at low temperature, so as to continuously output a stable flow of gaseous circulation medium without wasting heat and with high energy utilization.

[0054] Specifically, a first valve 221 is provided on the first buffer pipe 220 to control the input of liquid circulating medium into the heat extraction circulation component 100, and a second valve 222 is provided on the second buffer pipe 230 to control the input of liquid circulating medium into the buffer storage component 210.

[0055] Reference Figure 1 As shown, the buffer circulation component 200 can be connected to the circulation medium source 400 through the preprocessing component 240, which is used to preprocess the circulation medium.

[0056] In this embodiment, the circulating medium is water, and the circulating medium source 400 is a tap water network. The tap water in the tap water network has not been softened and is prone to scale buildup after heating, which affects the normal use of the workpiece.

[0057] Specifically, the pretreatment component 240 pre-treats the tap water, making it soft and convenient to put the softened tap water into the heat exchange circulation component 100 and the buffer circulation component 200 for use. This also extends the service life of the heat exchange circulation component 100 and the buffer circulation component 200, prevents them from being blocked by scale, and makes tap water inexpensive and convenient to use.

[0058] Among them, the pretreatment component 240 is a tap water softening and desalination device.

[0059] Reference Figure 1 As shown, the heat extraction circulation assembly 100 includes:

[0060] The medium storage unit 120 has a connected gas passage 110 and is connected to the buffer circulation assembly 200;

[0061] The heat extraction pipe 130 forms a circulation loop with the medium storage device 120, which can transport the circulating medium and is thermally connected to the external heat source 300.

[0062] It is understandable that the gas is connected to the medium storage unit 120. After heat extraction in the heat extraction pipe 130, the gaseous circulating medium and the liquid circulating medium are separated in the medium storage unit 120. The gaseous circulating medium storage unit 120 leaves the medium storage unit 120 through the gas channel 110. The liquid circulating medium mixes with the original liquid circulating medium in the medium storage unit 120. Most of the heat after heat extraction leaves with the gaseous circulating medium through the gas channel 110 and is utilized in the subsequent heat utilization device. A small amount of heat remains in the liquid circulating medium, mixes with the original liquid circulating medium, and can be transferred to the buffer storage unit 210 through the buffer circulation component 200 to store the small amount of heat. This achieves the temporary storage of excess heat in the high-temperature kiln, so that only a portion of the liquid circulating medium is heated and vaporized, thereby continuously outputting a stable flow of gaseous circulating medium.

[0063] It is worth understanding that the heat extraction pipe 130 can be connected to the kiln through direct or indirect heat conduction. In the case of direct heat conduction, the heat extraction pipe 130 is directly installed in the heat source 300 of the kiln; in the case of indirect heat conduction, the heat extraction pipe 130 is connected to the heat source 300 through a heat transfer medium.

[0064] It is worth understanding that the gas channel 110 can also be directly installed on the heat extraction pipe 130, located in the part of the heat extraction pipe 130 between the heat source 300 and the medium storage device 120. The connection between the gas channel 110 and the heat extraction pipe 130 is provided with a waterproof and breathable component, which allows gas to enter the gas channel 110 only from this point.

[0065] It is understandable that the increase in temperature of the liquid circulating medium inside the medium storage device 120 reduces the temperature difference between the liquid circulating medium and the gaseous circulating medium, thereby reducing the temperature difference load that the medium storage device 120 can withstand. This makes the selection of materials for the medium storage device 120 more convenient and lower in cost.

[0066] In this embodiment, a gas-liquid separator is provided inside the medium storage container 120. The gas-liquid separator completely separates the gaseous circulating medium and the liquid circulating medium inside the medium storage container 120, preventing some of the gaseous circulating medium from condensing and causing excessive heat in the medium storage container 120.

[0067] Among them, the medium storage device 120 is a steam drum.

[0068] Reference Figures 1 to 4 As shown, the industrial kiln wide-temperature-range waste heat stabilization steam generation process according to the second aspect embodiment of the present invention uses the industrial kiln wide-temperature-range waste heat stabilization steam generation device according to the first aspect embodiment of the present invention.

[0069] It is worth understanding that by using a wide-temperature-range waste heat stabilization steam generation device for industrial kilns, the vaporization rate of the circulating medium within the heat extraction circulation component 100 can be made more stable, facilitating stable steam output and adapting to a wider temperature range, thus improving the applicability.

[0070] In this embodiment, the heat extraction vaporization rate of the liquid circulating medium in the heat extraction circulation component 100 is controlled to be lower than a preset value.

[0071] It is worth understanding that the preset value is determined in advance by comprehensively considering the operating temperature range of the kiln, the heat extraction range of the heat extraction circulation component 100, and the heat exchange range of the buffer circulation component 200.

[0072] It is understandable that when the kiln is at high temperature, the buffer circulation component 200 exchanges heat with the liquid circulating medium in the heat extraction circulation component 100, reducing the temperature of the liquid circulating medium and maintaining it at a low temperature. Each heat extraction only involves a portion of the liquid circulating medium vaporizing, reducing the heat extraction vaporization rate of the liquid circulating medium in the circulation component to below a preset value. This allows for a continuous and stable output of gaseous circulating medium to the gas channel 110. Furthermore, the overall temperature of the liquid circulating medium in the buffer circulation component 200 and the heat extraction circulation component 100 gradually increases. Conversely, when the kiln is at low temperature, heat is extracted through the overall liquid circulating medium at a higher temperature. The higher temperature of the liquid circulating medium requires less heat for vaporization, ensuring that the vaporization rate does not decrease. This increases the heat extraction vaporization rate of the liquid circulating medium in the circulation component to near a preset value, allowing for a continuous and stable output of gaseous circulating medium to the gas channel 110.

[0073] In this embodiment, the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component 100 is adjusted according to the temperature of the heat source 300, the flow rate of the gas channel 110, and the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component 100, so as to drive a dynamic balance between the flow rate of the liquid circulating medium to be heated and the flow rate of the gas circulating medium.

[0074] The buffer circulation component 200 replenishes the liquid circulation medium from the circulation medium source 400, and replenishes the liquid circulation medium flow rate to the heat extraction circulation component 100 with an amount equal to the flow rate of the vaporized circulation medium.

[0075] The liquid circulating medium to be heated refers to the liquid circulating medium contained in the portion of the heat extraction pipe 130 located between the medium storage container 120 and the heat source 300 along its flow direction. The flow rate of the liquid circulating medium to be heated refers to the flow rate of the circulating medium that exchanges heat with the heat source 300 per unit time.

[0076] The gaseous circulating medium flow rate refers to the flow rate of the gaseous circulating medium passing through the gas channel 110 per unit time.

[0077] The heat extraction vaporization rate of the liquid circulating medium refers to the ratio of the flow rate of the gaseous circulating medium to the flow rate of the liquid circulating medium to be extracted in the heat extraction cycle that generates this gaseous circulating medium flow rate.

[0078] In this embodiment, a temperature detection element 310 is provided in the heat source 300, the heat source 300 is a kiln, a first flow meter is provided in the gas channel 110, and a second flow meter is provided in the heat extraction pipe 130.

[0079] It is understandable that when the kiln temperature is too high, the heat load is large. The flow rate in the gas channel 110 and the flow rate of the liquid circulating medium to be heated in the heat exchange circulation component 100 are monitored. When the flow rate of the gaseous circulating medium in the gas channel 110 is large, the flow rate of the liquid circulating medium to be heated in the heat exchange circulation component 100 is increased so that more liquid circulating medium can exchange heat, thereby reducing the vaporization rate of the liquid circulating medium, so as to continuously output a stable gaseous circulating medium and store the excess heat through the liquid circulating medium. When the kiln temperature is low, the flow rate in the gas channel 110 and the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component 100 are detected. When the flow rate of the gaseous circulating medium in the gas channel 110 decreases, the buffer circulation component 200 stops replenishing the liquid circulating medium from the circulating medium source 400, so that the temperature of the buffer circulation medium and the liquid circulating medium in the heat extraction circulation component 100 are maintained at the state after the temperature rise, so as to utilize the heat stored at high temperature, reduce the heat load required for the vaporization of the liquid circulating medium, and reduce the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component 100, so that less liquid circulating medium is exchanged for heat, improve the vaporization rate of the liquid circulating medium, and continuously output a stable gaseous circulating medium.

[0080] In this embodiment, the preset value of the heat extraction vaporization rate of the circulating medium is 20%, so the ratio of the flow rate of the heat extraction circulation component 100 to the flow rate of the gas channel 110 is controlled to be 5 or more.

[0081] Specifically, a circulation pump is installed on the part of the heat-extracting liquid circulating medium in the heat-extracting pipeline. The flow rate of the heat-extracting liquid circulating medium in the heat-extracting pipeline is controlled by the circulation pump. The specific flow rate can be controlled by controlling the flow velocity of the heat-extracting liquid circulating medium through the circulation pump.

[0082] In this embodiment, multiple cooling stages are divided according to the ratio range of the heat extraction load to the system design output load X. In different cooling stages, the buffer circulation component 200 controls the temperature of the liquid circulating medium to be extracted within the heat extraction circulation component 100 within a preset range.

[0083] The kiln is equipped with a temperature detection device 310. The real-time heat load can be calculated by processing the detected kiln temperature using a formula. The gas channel 110 is equipped with a first flow meter, which calculates the output load based on the flow rate of the gaseous circulating medium.

[0084] It is worth understanding that by selecting one or more output loads as the system design output load, the cooling stages are distinguished by the flow rate of the gaseous circulating medium. After detecting the real-time temperature of the kiln, the specific value of X is calculated and compared with the range corresponding to different cooling stages to determine the current cooling stage. Then, the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component 100 is controlled accordingly. This allows for real-time control based on the kiln temperature and the flow rate of the gas channel 110, facilitating the dynamic balance between the flow rate of the liquid circulating medium to be heated and the flow rate of the gaseous circulating medium.

[0085] In this embodiment, there are two cooling stages: a high-speed cooling stage corresponding to the high temperature of the heat source 300 and a low-speed cooling stage corresponding to the low temperature of the heat source 300.

[0086] If X is within the ratio range corresponding to the high-speed cooling stage, the buffer circulation component 200 and the heat extraction circulation component 100 perform liquid circulation medium heat exchange circulation. The flow rate of the liquid circulation medium input into the buffer circulation component 200 is adjusted according to the flow rate of the gas channel 110 and the flow rate of the liquid circulation medium input into the buffer circulation component 200 of the heat extraction circulation component 100.

[0087] If X is within the ratio range corresponding to the low-speed cooling stage, the buffer circulation component 200 stops replenishing liquid circulation medium from the circulation medium source 400, the buffer circulation component 200 continues to supply circulation medium to the heat extraction circulation component 100, and the heat exchange circulation of liquid circulation medium between the heat extraction circulation components 100 is reduced to the minimum or shut down until the liquid level of the liquid circulation medium in the buffer circulation component 200 drops to the minimum, and then the liquid circulation medium is replenished to the buffer circulation component 200.

[0088] It is understandable that the high temperature of the kiln corresponds to the high-speed cooling stage. At this time, the heat load is large, and the liquid circulating medium in the heat extraction circulation component 100 needs to extract heat at high speed to avoid excessive vaporization of the liquid circulating medium and the storage of more heat in the liquid circulating medium. At this time, the buffer circulation component 200 exchanges heat with the liquid circulating medium in the heat extraction circulation component 100, so that the heat is transferred to the buffer circulation component 200. At the same time, the buffer circulation component 200 introduces new room temperature circulating medium through the circulating medium source 400, further reducing the overall temperature of the liquid circulating medium in the heat extraction circulation component 100 and the buffer circulation component 200. Furthermore, the flow rate of the buffer circulation component 200 input to the heat extraction circulation component 100 is equal to the sum of the vaporization amount of the liquid circulating medium and the flow rate of the heat extraction circulation component 100 input to the buffer circulation component 200, so as to reduce the vaporization rate of the liquid circulating medium to a preset value and achieve a stable output of the gaseous circulating medium flow rate, which is convenient for use in subsequent heat utilization devices.

[0089] It is understandable that the low temperature of the kiln corresponds to the low-speed cooling stage. At this time, the heat load is relatively small, and the liquid circulating medium in the heat extraction circulation component 100 needs to extract heat at a low speed to avoid too little liquid circulating medium vaporization and less heat being stored in the liquid circulating medium. In addition, the buffer circulation component 200 stops replenishing the liquid circulating medium from the circulating medium source 400. At this time, the liquid circulating medium in the buffer circulation component 200 and the heat extraction circulation component 100 contains heat stored from the high temperature of the kiln, and its overall temperature is relatively high. The heat required for vaporization is lower, making it easier to vaporize. At the same time, the heat exchange between the heat extraction circulation component 100 and the buffer circulation component 200 is reduced, reducing the heat loss of the liquid circulating medium, so as to improve the vaporization rate of the liquid circulating medium to be close to the preset value, and achieve a stable output of the gaseous circulating medium flow rate, which is convenient for use in subsequent heat utilization devices.

[0090] Reference Figure 2 As shown, the buffer storage 210 is equipped with a water level detection device. The water level in the buffer storage 210 is detected by the water level detection device. During the high-speed cooling stage, the water level in the buffer storage 210 is kept constant by controlling the flow rate of the gaseous circulating medium to be the same as the flow rate of the replenished liquid circulating medium. During the low-speed cooling stage, it is ensured that when the water level in the buffer storage 210 drops to the lowest level, water can be replenished through the circulating medium source 400.

[0091] Reference Figure 3 As shown, during the high-speed cooling stage, the circulating pump on the heat extraction pipe 130 controls the flow rate of the liquid circulating medium to be heated to increase, thereby increasing its flow rate, to maintain a dynamic balance between the flow rate of the liquid circulating medium and the flow rate of the gaseous circulating medium, i.e., the ratio between the two is fixed. During the low-speed cooling stage, the circulating pump on the heat extraction pipe 130 controls the flow rate of the liquid circulating medium to be heated to decrease, thereby decreasing its flow rate, to maintain a dynamic balance between the flow rate of the liquid circulating medium and the flow rate of the gaseous circulating medium, i.e., the ratio between the two is fixed. Furthermore, in this embodiment, the flow rate of the liquid circulating medium to be heated during the low-speed cooling stage is above 0.5 m / s, and the cross-sectional area of ​​the heat extraction pipe 130 can be controlled by other valves to maintain the flow rate of the liquid circulating medium to be heated.

[0092] Reference Figure 4As shown, the buffer circulation assembly 200 is equipped with a buffer circulation pump on the first buffer pipe 220. The buffer circulation pump can control the flow rate of the heat exchange circulation assembly 100 input into the first buffer pipe 220. During the high-speed cooling stage, heat exchange occurs due to the opening of the second valve. The buffer circulation pump controls the flow rate of the heat exchange circulation assembly 100 input into the first buffer pipe 220 to maintain the internal pressure of the medium storage container 120 in the working state, thereby maintaining the water level in the medium storage container 120 and maintaining the space ratio between the gaseous circulation medium and the liquid circulation medium. During the low-speed cooling stage, the circulation medium input into the medium storage container 120 can be controlled, and the second valve can be partially closed or closed.

[0093] The following description uses a graphitization furnace as an example. It should be understood that the following content does not constitute a specific limitation on the present invention.

[0094] The system status is divided into the charging, heating, cooling and discharging stages according to the operating conditions of the graphitization furnace.

[0095] In the initial cooling stage of the graphitization furnace, the furnace core temperature is 3000℃, the furnace wall side insulation layer temperature is 1000℃, the discharge temperature is 400℃, and heat is extracted from the insulation layer position at 1100℃ inside the furnace. The temperature in the later stage of cooling is 400℃.

[0096] Based on the size of the graphitization furnace, the 60t capacity graphitization furnace is selected to supply 2MPa saturated steam externally, with an external heating steam volume of 2.5t / h.

[0097] The water replenishment temperature is 30℃, and the buffer water tank is designed to be 190℃.

[0098] The preset value for the heat extraction vaporization rate of the heat extraction cycle system is 20%.

[0099] Loading stage: The system starts to fill with water, the steam drum water level is replenished to the normal level, and the buffer water tank is replenished to the high level.

[0100] Heating stage: The system receives the temperature signal of the graphitization furnace insulation layer, turns on the circulation pump on the heat extraction pipe 130, and starts the heat extraction circulation; the circulation pump flow rate is adjusted according to the temperature of the circulating medium at the outlet of the heat extraction pipe 130 of the graphitization furnace, and the temperature of the pipe wall of the heat extraction pipe 130 is controlled not to exceed the film boiling point temperature.

[0101] Cooling stage: The cooling stage is divided into a high-speed cooling stage and a low-speed cooling stage, with the ratio of heat load to system design output as the basis for judgment.

[0102] When the ratio of the heat extraction load to the system design output load is greater than 1, it is the high-speed cooling stage. At this time, the flow rate of the liquid circulating medium to be extracted in the heat extraction pipe 130 is controlled by the flow rate of the gaseous circulating medium, and the heat extraction vaporization rate is controlled to be below 20%. The system water replenishment is equal to the flow rate of the gaseous circulating medium. At the same time, the second valve 222 on the second buffer pipe 230 of the buffer circulation component 200 is gradually opened to maintain the pressure of the medium storage device 120 at 2MPa. The flow rate of the buffer circulation pump is the sum of the flow rate in the second buffer pipe 230 and the flow rate of the liquid circulating medium corresponding to the flow rate of the gaseous circulating medium.

[0103] When the ratio of the heat extraction load to the system design output load is less than 1, the system is in a low-speed cooling stage. The flow rate of the buffer circulation pump into the buffer storage unit 210 gradually decreases, and the heat vaporization rate of the stable steam-generating device of the graphitization furnace is always controlled below 20%, while maintaining the flow velocity in the heat extraction pipeline 130 at no less than 0.5 m / s. The buffer storage unit 210 no longer replenishes the circulating medium from the circulating medium source 400. The second valve 222 of the second buffer pipeline 230 is kept in the minimum position, and the medium storage unit 120 is supplied by the buffer storage unit 210. The water level in the buffer storage unit 210 gradually decreases until the minimum required water level is reached, and then water is replenished through the circulating medium source 400.

[0104] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A process for steam generation from waste heat in a wide temperature range in an industrial furnace, characterized in that, include: A heat extraction circulation assembly for extracting heat from a heat source, having a liquid circulation medium capable of being vaporized by heat extraction and a gas channel for conveying the gaseous circulation medium; The buffer circulation component is connected to the heat extraction circulation component and can exchange heat with the liquid circulation medium in the heat extraction circulation component. It can also be connected to the circulation medium source to replenish the liquid circulation medium. The heat extraction vaporization rate of the liquid circulating medium in the heat extraction circulation component is controlled to be lower than a preset value; Based on the temperature of the heat source, the flow rate of the gas channel, and the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component, the flow rate of the liquid circulating medium to be heated in the heat extraction circulation component is adjusted to drive a dynamic balance between the flow rate of the liquid circulating medium to be heated and the flow rate of the gas circulating medium. The buffer circulation component replenishes liquid circulation medium from the circulation medium source and adds a liquid circulation medium flow rate equal to the flow rate of the vaporized circulation medium to the heat extraction circulation component; Based on the ratio range of heat load to system design output load X, multiple cooling stages are divided. In different cooling stages, the buffer circulation component controls the temperature of the liquid circulating medium to be heated in the heat circulation component within the preset range. It includes two cooling stages: a high-speed cooling stage corresponding to the high temperature of the heat source and a low-speed cooling stage corresponding to the low temperature of the heat source. If X is within the ratio range corresponding to the high-speed cooling stage, the buffer circulation component and the heat extraction circulation component undergo liquid circulation heat exchange. The flow rate of the buffer circulation component into the heat extraction circulation component is adjusted according to the flow rate of the gas channel and the flow rate of the liquid circulation medium input from the heat extraction circulation component into the buffer circulation component. If X is within the ratio range corresponding to the low-speed cooling stage, the buffer circulation component stops replenishing liquid circulation medium from the circulation medium source, the buffer circulation component continues to supply circulation medium to the heat extraction circulation component, and the liquid circulation medium heat exchange circulation between the heat extraction circulation components is reduced to the minimum or shut down until the liquid level of the liquid circulation medium in the buffer circulation component drops to the minimum, and then the liquid circulation medium is replenished to the buffer circulation component again.

2. The process as claimed in claim 1, wherein, The buffer loop component includes: Buffer storage; The first buffer pipe connects the buffer storage unit and the heat extraction circulation assembly, and is capable of delivering the liquid circulation medium into the heat extraction circulation assembly; The second buffer pipe connects the buffer storage unit and the heat extraction circulation assembly, and is capable of delivering the liquid circulation medium into the buffer storage unit.

3. The industrial kiln wide-temperature-range waste heat stabilization steam generation process according to claim 1, characterized in that, The buffer circulation component can be connected to the circulation medium source through a preprocessing component, which is used to preprocess the circulation medium.

4. The industrial kiln wide-temperature-range waste heat stabilization steam generation process according to claim 1, characterized in that, The heat extraction circulation component includes: The medium storage unit has the gas passage connected to it and is connected to the buffer circulation assembly; The heat extraction pipeline forms a circulation loop with the medium storage container, enabling it to transport the circulating medium and connect to an external heat source for heat conduction.

5. The industrial kiln wide-temperature-range waste heat stabilization steam generation process according to claim 4, characterized in that, The medium storage device is equipped with a gas-liquid separator.

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