System and method for recycling waste heat of tail end shift gas of shift process system

Abstract

The invention relates to the technical field of waste heat recovery in the coal chemical industry, in particular to a system for recycling waste heat of shift gas at the tail end of a shift process system, which comprises a demineralized water heat exchanger, a shift gas water cooler and a waste heat recovery module arranged between the demineralized water heat exchanger and the shift gas water cooler. The waste heat recovery module is additionally arranged behind the demineralized water heat exchanger, heat originally taken away by circulating water is used for preheating domestic water and heating water, the originally abandoned heat is recycled, the consumption of the circulating water is reduced, and meanwhile, the energy consumption of subsequent heating for steam / electric heating is reduced; meanwhile, initial conveying modes can be flexibly switched according to different seasons and heating peak periods through the intermediate control module, the demand differences of living water and heating water in different periods are accurately matched, and the conveying flow of process gas or the input condition of low-pressure heating steam is dynamically adjusted according to the actual water use condition; heat load changes of living quarters and factories are automatically identified, and limited waste heat resources are intelligently distributed.

Description

Technical Field

[0001] This application relates to the field of waste heat recovery technology in coal chemical industry, and in particular to a system and method for recovering and utilizing waste heat from the terminal phase of a shift converter system. Background Technology

[0002] In the shift conversion unit of a coal chemical purification plant, a partial shift conversion process is typically employed. After the crude coal gas is cooled by a waste heat boiler and condensate is separated, a portion enters the shift converter for the shift reaction, while the other portion serves as a distribution gas without undergoing shift conversion. The two are then combined to adjust the hydrogen-to-carbon ratio. The combined process gas undergoes multi-stage separation and heat exchange, sequentially entering a demineralized water heat exchanger and a shift gas water cooler. Finally, it is cooled to approximately 40°C and then sent to an ammonia scrubbing tower for washing before being delivered to the acid gas removal unit.

[0003] In existing designs, various production sectors widely utilize high- and medium-temperature waste heat (above 150°C) primarily for steam generation and power generation. However, low-grade waste heat (below 150°C) is mainly cooled by consuming large amounts of circulating water. For example, in the aforementioned process, after the shift gas passes through a demineralized water heat exchanger to approximately 60°C, it still retains significant waste heat. However, in current processes, this heat is directly transferred to a water cooler and carried away by the circulating water. This not only wastes low-grade heat energy but also increases the load on the circulating water system (water consumption, fan energy consumption). Furthermore, the domestic water and heating water in the plant and living areas require significant amounts of steam or electricity for heating. With the increasing emphasis on green, low-carbon, and energy-saving practices in recent years, we propose an energy-saving upgrade measure to optimize the waste heat recovery of the shift gas at the end of the shift system, aiming to fully recover and utilize the waste heat. Summary of the Invention

[0004] This application provides a system and method for recovering and utilizing waste heat from the end-of-pipe shift gas in a shift process system, in order to solve the problem in the prior art that the lack of recovery and utilization of waste heat from low-grade shift gas leads to a large waste of usable thermal energy and a low waste heat recovery and utilization rate.

[0005] This application provides a system for recovering and utilizing waste heat from the terminal phase of a shift converter system, comprising: It includes a demineralized water heat exchanger and a shift gas water cooler, wherein the input end of the demineralized water heat exchanger is connected to the process gas after multi-stage separation, and the input end of the shift gas water cooler is connected to the output end of the demineralized water heat exchanger through a process gas branch pipe. Also includes: The waste heat recovery module includes a domestic water heat exchange module and a heating water heat exchange module. The domestic water heat exchange module and the heating water heat exchange module are arranged in parallel between the demineralized water heat exchanger and the change gas water cooler, and are used to perform secondary recovery of the waste heat of the process gas after heat exchange in the demineralized water heat exchanger. An intermediate control module, located between the demineralized water heat exchanger and the waste heat recovery module, is used to control the delivery mode and flow rate of the process gas delivered to the domestic water heat exchanger and the heating water heat exchanger.

[0006] Preferably, the intermediate control module includes: The first control module is configured with three initial supply modes, which can control the waste heat recovery module to operate in a corresponding initial supply mode according to the actual heating peak period. The second control module includes a sub-determination module, which can control the actual delivery status of the domestic water heat exchange module and the heating water heat exchange module according to the actual water usage in the living area.

[0007] Preferably, the three initial supply modes are domestic water priority mode, heating water priority mode, and normal supply mode, wherein: The domestic water priority mode means that during the non-heating season, the intermediate control module will control the process gas to be preferentially supplied to the domestic water heat exchange module through the first control module. The heating water priority mode means that during peak heating periods, the intermediate control module will control the process gas to be preferentially supplied to the heating water heat exchange module through the first control module. The normal supply mode is as follows: during the normal heating season, the intermediate control module will control the process gas to be supplied to the domestic water heat exchange module and the heating water heat exchange module at the same flow rate through the first control module.

[0008] Preferably, one end of the domestic water heat exchange module and the heating water heat exchange module is also supplied with low-pressure heating steam to provide additional heating for the domestic water heat exchange module and / or the heating water heat exchange module.

[0009] Preferably, the sub-determination module is a flow rate determination sub-module, which can determine the actual water usage by determining the water flow rate through the domestic water heat exchange module and the heating water heat exchange module.

[0010] Preferably, the traffic determination submodule includes: A flow monitoring device is installed at the inlet or outlet of the domestic water heat exchange module and the heating water heat exchange module to collect the actual water flow rate passing through the domestic water heat exchange module or the heating water heat exchange module per unit time. The first determination submodule is connected to the flow monitor and is equipped with a preset determination flow rate, which is used to determine the actual water flow rate collected.

[0011] Preferably, the first determination submodule can determine the actual water flow rate at the domestic water heat exchange module or the heating water heat exchange module in the current mode through the preset determination flow rate, so as to control the actual flow rate of process gas at each heat exchange module. The preset determination flow rate includes a preset domestic water flow rate and a preset heating water flow rate. The determination process is as follows: If the actual water flow rate at the domestic water heat exchange module in the current mode is greater than the preset domestic water flow rate, and the actual water flow rate at the heating water heat exchange module in the current mode is less than or equal to the preset heating water flow rate, then the intermediate control module will increase the flow rate of process gas delivered to the domestic water heat exchange module through the first control module. If the actual water flow rate at the heating water heat exchange module in the current mode is greater than the preset heating water flow rate, and the actual water flow rate at the domestic water heat exchange module is less than or equal to the preset domestic water flow rate, then the intermediate control module will increase the flow rate of process gas delivered to the heating water heat exchange module through the first control module. If the actual water flow rate at the domestic water heat exchange module in the current mode is greater than the preset domestic water flow rate, and the actual water flow rate at the heating water heat exchange module is also greater than the preset heating water flow rate, then the intermediate control module will increase the input flow rate of the low-pressure heating steam into the two heat exchange modules through the first control module.

[0012] Preferably, the determination submodule is a temperature difference determination submodule, which can determine the actual water usage by determining the actual temperature difference between the domestic water heat exchange module and the heating water heat exchange module within a unit time. The temperature difference determination submodule includes: A temperature monitoring instrument is installed on the domestic water heat exchange module and the heating water heat exchange module to collect the actual temperature difference at the domestic water heat exchange module or the heating water heat exchange module per unit time. The second determination submodule is connected to the temperature monitor and is equipped with a preset determination temperature difference, which is used to determine the actual temperature difference collected.

[0013] Preferably, the second determination submodule can determine the actual temperature difference at the domestic water heat exchange module or the heating water heat exchange module through the preset determination temperature difference, so as to control the actual flow rate of process gas at each heat exchange module. The preset determination temperature difference includes a preset domestic water temperature difference and a preset heating water temperature difference. The determination process is as follows: If the actual temperature difference at the domestic water heat exchange module in the current mode is greater than the preset domestic water temperature difference, and the actual temperature difference at the heating water heat exchange module is less than or equal to the preset heating water temperature difference, then the intermediate control module will increase the flow rate of the process gas delivered to the domestic water heat exchange module through the first control module. If the actual temperature difference at the heating water heat exchange module in the current mode is greater than the preset heating water temperature difference, and the actual temperature difference at the domestic water heat exchange module is less than or equal to the preset domestic water constant temperature difference, then the intermediate control module will increase the flow rate of the process gas delivered to the heating water heat exchange module through the first control module. If the actual temperature difference at the domestic water heat exchange module in the current mode is greater than the preset domestic water temperature difference, and the actual temperature difference at the heating water heat exchange module is also greater than the preset heating water temperature difference, then the intermediate control module will increase the input flow rate of the low-pressure heating steam into the two heat exchange modules through the first control module.

[0014] This application also provides a method for recovering waste heat from the terminal phase of a shift converter system based on any of the above-mentioned methods, comprising: Step S1: Introduce the process gas after multi-stage separation into the demineralized water heat exchanger for preliminary heat exchange and cooling. Step S2: Select the operating mode through the intermediate control module according to the current season and heating demand. The operating mode includes domestic water priority mode, heating water priority mode or normal supply mode. Step S3: The process gas after heat exchange in the demineralized water heat exchanger is delivered to the domestic water heat exchange module and the heating water heat exchange module respectively through the intermediate control module according to the initial distribution ratio of the selected operating mode. Step S4: Real-time acquisition of the actual water flow rate or actual temperature difference passing through the domestic water heat exchange module and the heating water heat exchange module through the flow rate determination submodule and / or temperature difference determination submodule; Step S5: Compare the collected actual values ​​with the preset judgment flow rate or preset judgment temperature difference in the corresponding mode, and dynamically adjust the process gas flow rate delivered to each heat exchange module according to the comparison results; if the actual demand exceeds the corresponding preset value, start or increase the input flow rate of low-pressure heating steam for auxiliary heating. Step S6: The process gas that has been cooled by heat exchange in the waste heat recovery module is combined and sent to the shift gas water cooler for final cooling, and then sent to the ammonia washing tower for further processing.

[0015] The beneficial effects of this application are as follows: This application discloses a system and method for recovering and utilizing waste heat from the end-of-pipe conversion process. By adding a waste heat recovery module after the demineralized water heat exchanger, the heat that would otherwise be carried away by the circulating water is used to preheat domestic water and heating water. This recovers and utilizes the previously wasted heat, reducing circulating water consumption and minimizing energy consumption for subsequent steam / electric heating. Simultaneously, the intermediate control module can flexibly switch the initial delivery mode according to different seasons and peak heating periods, precisely matching the varying demands of domestic water and heating water at different times. It also dynamically adjusts the flow rate of process gas or the input of low-pressure heating steam based on actual water usage, automatically identifying heat load changes in the living area and the plant area, and intelligently allocating limited waste heat resources to ensure temperature stability of domestic water and heating water during supply. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of the system for recycling waste heat from the end-stage shift process gas provided in the embodiments of this application; Figure 2 A schematic flowchart illustrating the method for recycling waste heat from the end-of-pipe converter gas in an embodiment of this application.

[0018] Figure label: 100. Demineralized water heat exchanger; 200. Gas shifter water cooler; 300. Waste heat recovery module; 400. Intermediate control module; 500. Ammonia washing tower; 1. Domestic water heat exchanger; 2. Domestic water collection tank; 3. Domestic water booster pump; 4. Low-pressure heating steam end on the domestic water side; 5. Heating water heat exchanger; 6. Heating water collection tank; 7. Heating water booster pump; 8. Low-pressure heating steam end on the heating water side. Detailed Implementation

[0019] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The following is combined Figure 1 and Figure 2This application describes the system and method for recycling waste heat from the end-of-line conversion gas of the conversion process system provided in the embodiments of this application.

[0021] Reference Figure 1 As shown in the embodiment of this application, the system for recovering and utilizing the waste heat of the shift process gas at the end of the shift process is integrated into the end of the shift process, mainly including a demineralized water heat exchanger 100, a shift gas water cooler 200, and a waste heat recovery module 300 disposed between the two. The demineralized water heat exchanger 100 is located after the crude water-gas shift section (water separator) and performs preliminary water cooling on the process gas in the shift gas distribution section. The input end of the shift gas water cooler 200 is connected to the output end of the demineralized water heat exchanger 100 through a corresponding process gas branch pipe, and its output end is connected to the input end of the ammonia scrubbing tower 500.

[0022] Specifically, the process gas from the preceding process section at approximately 147.6°C is separated and first enters the demineralized water heat exchanger 100. After exchanging heat with the demineralized water and cooling down to approximately 60°C, the process gas is divided into two paths. One path is a direct branch, through which the process gas can directly go to the process gas water cooler 200 without activating the waste heat recovery module 300. The other path enters the waste heat recovery branch, where it is distributed by the intermediate control module 400 to recover the waste heat.

[0023] The waste heat recovery module 300 is composed of a domestic water heat exchange module and a heating water heat exchange module. The domestic water heat exchange module includes a domestic water heat exchanger 1, a domestic water collection tank 2, and a domestic water booster pump 3. The heat source input end (process gas side) of the domestic water heat exchanger 1 is connected to the output end of the demineralized water heat exchanger 100, and the output end of the heat source is connected to the input end of the converter water cooler through a process gas branch pipe. The heat source input end of the domestic water heat exchanger 1 is connected to the external domestic water self-boundary zone pipe network.

[0024] The input end of the domestic water collection tank 2 is connected to the output end of the heat exchange source of the domestic water heat exchanger 1, and its output end is connected to the external domestic water outflow network through the domestic water booster pump 3.

[0025] One side of the domestic water collection tank 2 is also connected to the external low-pressure heating steam through the domestic water side low-pressure heating steam end 4, which is used for auxiliary heating when its temperature does not meet the domestic water supply temperature.

[0026] The heating water heat exchange module includes a heating water heat exchanger 5, a heating water collection tank 6, a heating water booster pump 7, and a low-pressure heating steam end 8 on the heating water side. Its connection method is basically similar to that of the domestic water heat exchange module, and will not be described in detail here.

[0027] Specifically, in the domestic water heat exchanger 1, ambient temperature domestic water from the domestic water boundary network is heated by process gas. The heated domestic water can then enter the domestic water collection tank 2 for temporary storage. The domestic water collection tank 2 is also equipped with a temperature sensor. If the water temperature reaches the preset set value, it can be sent by the domestic water booster pump 3 to the corresponding domestic water boundary network in the plant area and living area for configuration and use. If the water temperature in the tank is lower than the required set value due to insufficient heat from the process gas, the low-pressure heating steam connected to the bottom of the tank can be turned on to supplement the heat and ensure a stable water supply temperature. The process on the heating water side is similar. Heating water from the heating water boundary network is preheated in the heating water heat exchanger 5, then enters the heating water collection tank 6. If necessary, it is supplemented with low-pressure heating steam at the corresponding end to be heated to a higher temperature, and finally sent out by the heating water booster pump 7.

[0028] By adding a waste heat recovery module 300 after the demineralized water heat exchanger 100, the heat that was originally carried away by the circulating water is used to preheat domestic water and heating water, and the heat that was originally wasted is recovered and utilized, which reduces the consumption of circulating water and reduces the energy consumption of steam / electric heating for subsequent heating. By setting up a domestic water heat exchange module and a heating water heat exchange module in parallel between the demineralized water heat exchanger 100 and the shift gas water cooler 200, secondary waste heat recovery is performed on the process gas after heat exchange in the demineralized water heat exchanger 100. This fully taps the waste heat potential of the shift gas at the end of the shift process system, avoids energy waste, and meets the development requirements of green, low-carbon, energy-saving and consumption-reducing.

[0029] In some specific embodiments, an intermediate control module 400 is provided between the demineralized water heat exchanger 100 and the waste heat recovery module 300. This module includes a first control module and a second control module.

[0030] The first control module is equipped with three initial supply modes. Through the first control module, the system can control the waste heat recovery module 300 to operate in a corresponding initial supply mode according to the actual heating peak period.

[0031] The second control module includes a judgment submodule, which controls the operating power of two corresponding modules in the waste heat recovery module 300 according to real-time usage requirements.

[0032] In some specific embodiments, the first control module in the intermediate control module 400 presets three initial supply modes according to the factory's operating calendar: a "domestic water priority mode" is executed during non-heating seasons or peak domestic water usage periods, such as morning and evening time zones; a "heating water priority mode" is executed during cold winter periods or nighttime time zones; and a "normal supply mode" is executed during spring and autumn or other time periods. In different modes, the first control module can control the corresponding valves in the pipeline to distribute the process gas to the domestic water heat exchanger 1 and the heating water heat exchanger 5 according to a preset ratio.

[0033] Specifically, the three initial delivery modes are as follows: The domestic water priority mode is applicable during the non-heating season. The intermediate control module 400 controls the process gas to prioritize the supply of domestic water heat exchange modules. The flow ratio of the two during priority supply can be specifically determined based on the ratio of the water flow required by the domestic water heat exchange modules and the water flow required by the heating water heat exchange modules during the non-heating season.

[0034] The heating water priority mode is suitable for peak heating periods. The intermediate control module 400 controls the process gas to prioritize the supply of heating water to the heating water heat exchange module. The flow ratio of the two during priority supply can be specifically determined based on the ratio of the water flow required by the domestic water heat exchange module and the water flow required by the heating water heat exchange module during peak heating periods.

[0035] Normal supply mode: Applicable to normal heating season. The intermediate control module 400 controls the supply of process gas to both the domestic water heat exchange module and the heating water heat exchange module at the same flow rate.

[0036] The determination submodule within the second control module is responsible for fine-tuning in the later stages. It can be a flow determination submodule and / or a temperature difference determination submodule. It collects the actual water flow or actual temperature difference flowing through the domestic water heat exchange module and the heating water heat exchange module within a fixed time period, compares the collected actual values ​​with the preset determination flow or preset determination temperature difference in the corresponding mode, and dynamically adjusts the process gas flow rate delivered to each heat exchange module based on the comparison results.

[0037] Specifically, taking the flow determination submodule as an example, it has flow monitoring instruments installed on the inlet or outlet pipes of domestic water and heating water. This submodule can continuously compare the actual flow rate within a fixed time period with the "preset determination flow rate" in the current mode. Assuming the current mode is "normal supply mode", the preset flow rates of domestic water and heating water are both rated values. If the actual flow rate of domestic water suddenly increases and exceeds the preset value, while the flow rate of heating water is normal, the flow determination submodule will send an instruction to the first control module to temporarily increase the proportion of process gas allocated to domestic water heat exchanger 1 and reduce the proportion going to heating water heat exchanger 5, thereby quickly responding to the surge in domestic hot water demand. If both flow rates far exceed the preset values, it indicates that the total heat demand has exceeded the waste heat supply capacity, and the module will simultaneously start the low-pressure heating steam of both systems for auxiliary heating.

[0038] The specific determination process is as follows: the preset determination flow includes the preset domestic water flow and the preset heating water flow.

[0039] If the actual water flow rate at the domestic water heat exchange module in the current mode is greater than the preset domestic water flow rate, and the actual water flow rate at the heating water heat exchange module in the current mode is less than or equal to the preset heating water flow rate, this indicates that the actual domestic water consumption is relatively high under the current conditions. Therefore, the supply of process gas to the domestic water heat exchange module needs to be appropriately increased to meet the normal operation requirements of this mode. In this case, the intermediate control module 400 will increase the process gas supply flow rate to the domestic water heat exchange module through the first control module. The specific increase can be calculated as [(actual water flow rate / preset domestic water flow rate) × rated (normal) supply flow rate under the current supply mode].

[0040] If the actual water flow rate at the heating water heat exchange module in the current mode is greater than the preset heating water flow rate, and the actual water flow rate at the domestic water heat exchange module is less than or equal to the preset domestic water flow rate, it indicates that the actual water consumption for heating is relatively high under the current conditions. In this case, the supply of process gas to the heating water heat exchange module can be appropriately increased. The intermediate control module 400 will then increase the flow rate of process gas supplied to the heating water heat exchange module through the first control module. The specific increase can be calculated as [(actual water flow rate / preset heating water flow rate) × rated (normal) supply flow rate under the current supply mode].

[0041] If the actual water flow rate at the domestic water heat exchange module in the current mode is greater than the preset domestic water flow rate, and the actual water flow rate at the heating water heat exchange module is also greater than the preset heating water flow rate, then the intermediate control module 400 will increase the input flow rate of low-pressure heating steam to the two heat exchange modules through the first control module. This indicates that the current water consumption for both heating and domestic water is relatively high and exceeds the normal water consumption under this mode. To ensure that the water supply temperature meets the supply temperature, it is necessary to start the low-pressure heating steam supply at the corresponding module, or increase the input of low-pressure heating steam at the corresponding module for auxiliary heating, so as to avoid affecting the normal operation of the waste heat recovery module 300, and thus affecting the normal domestic or heating water situation in the living area.

[0042] As another embodiment of this application, the determination submodule can be a temperature difference determination submodule. The temperature difference determination submodule can determine the actual water usage by determining the actual temperature difference between the domestic water heat exchange module and the heating water heat exchange module within a unit time.

[0043] The temperature difference determination submodule includes a temperature monitor and a second determination submodule. The temperature monitor is installed on the domestic water heat exchange module and the heating water heat exchanger 5 to collect the actual temperature difference. The second determination submodule is set with a preset determination temperature difference.

[0044] The determination process is as follows: The preset temperature difference includes the preset domestic water temperature difference and the preset heating water temperature difference.

[0045] If the actual temperature difference at the domestic water heat exchange module in the current mode is greater than the preset domestic water temperature difference, and the actual temperature difference at the heating water heat exchange module is less than or equal to the preset heating water temperature difference, then the intermediate control module 400 will increase the flow rate of the process gas delivered to the domestic water heat exchange module through the first control module.

[0046] If the actual temperature difference at the heating water heat exchange module in the current mode is greater than the preset heating water temperature difference, and the actual temperature difference at the domestic water heat exchange module is less than or equal to the preset domestic water constant temperature difference, then the intermediate control module 400 will increase the flow rate of the process gas delivered to the heating water heat exchange module through the first control module.

[0047] If the actual temperature difference at the domestic water heat exchange module in the current mode is greater than the preset domestic water temperature difference, and the actual temperature difference at the heating water heat exchange module is also greater than the preset heating water temperature difference, then the intermediate control module 400 will increase the input flow rate of the low-pressure heating steam entering the two heat exchange modules through the first control module. Its specific control principle is similar to that of the first determination submodule and will not be elaborated further here.

[0048] The process gas, cooled by heat exchangers 1 (domestic water heat exchanger) and 5 (heating water heat exchanger 5), (temperature reduced to 45-50℃) mixes with the process gas from the direct branch or enters the shift gas water cooler 200 directly. Even after mixing, the gas temperature is lower than the originally designed temperature for entering the shift gas water cooler 200, thus significantly reducing the circulating water cooling load of the shift gas water cooler 200. Finally, after being cooled to approximately 40℃ by the shift gas water cooler 200, the gas enters the ammonia scrubbing tower 500 for further processing.

[0049] Meanwhile, the intermediate control module 400 can flexibly switch the initial delivery mode according to different seasons and peak heating periods, accurately match the demand differences of domestic water and heating water at different times, and dynamically adjust the delivery flow of process gas or the input of low-pressure heating steam according to the actual water usage. It can automatically identify the heat load changes of the living area and the plant area, and intelligently allocate limited waste heat resources to ensure the temperature stability of domestic water and heating water during the supply period.

[0050] Among them, the three initial delivery modes configured by the first control module can be flexibly switched according to different seasons and heating peak periods to accurately match the different needs of domestic water and heating water at different times; the second control module monitors the actual water use in real time through the flow determination submodule or temperature difference determination submodule, and dynamically adjusts the process gas delivery flow rate or low-pressure heating steam input flow rate to ensure the stability of the supply temperature of domestic water and heating water.

[0051] In some specific embodiments, such as Figure 2As shown, this application also provides a method for recovering waste heat from the terminal shift gas of a shift converter system based on any of the above claims, comprising: The process gas, after undergoing multi-stage separation, is introduced into the demineralized water heat exchanger 100 for initial heat exchange and cooling. Based on the current season and heating demand, the intermediate control module 400 selects the operating mode, which includes domestic water priority mode, heating water priority mode, or normal supply mode. The process gas, after heat exchange in the demineralized water heat exchanger 100, is then distributed to the domestic water heat exchange module and the heating water heat exchange module respectively, according to the initial distribution ratio of the selected operating mode, via the intermediate control module 400. The flow rate determination submodule and / or temperature difference determination submodule collect data on the flow through the gas in real time. The actual water flow rate or actual temperature difference of the domestic water heat exchange module and the heating water heat exchange module is measured; the actual values ​​are compared with the preset judgment flow rate or preset judgment temperature difference in the corresponding mode, and the process gas flow rate delivered to each heat exchange module is dynamically adjusted according to the comparison results; if the actual demand exceeds the corresponding preset value, the input flow rate of low-pressure heating steam is started or increased for auxiliary heating; the process gas after being cooled by the waste heat recovery module 300 is combined and delivered to the conversion gas water cooler 200 for final cooling, and then sent to the ammonia washing tower 500 for subsequent processing.

[0052] Specifically, the system for recycling waste heat from the end-of-line conversion process provided in this application embodiment can perform the above-mentioned recycling method to achieve the desired technical effect, which will not be elaborated further here.

[0053] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0055] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0056] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A system for recovering and utilizing waste heat from the shift gas at the end of a shift process system, comprising a demineralized water heat exchanger and a shift gas water cooler, wherein the input end of the demineralized water heat exchanger is connected to the process gas after multi-stage separation, and the input end of the shift gas water cooler is connected to the output end of the demineralized water heat exchanger via a process gas branch pipe, characterized in that, Also includes: The waste heat recovery module includes a domestic water heat exchange module and a heating water heat exchange module. The domestic water heat exchange module and the heating water heat exchange module are arranged in parallel between the demineralized water heat exchanger and the change gas water cooler, and are used to perform secondary recovery of the waste heat of the process gas after heat exchange in the demineralized water heat exchanger. An intermediate control module, located between the demineralized water heat exchanger and the waste heat recovery module, is used to control the delivery mode and flow rate of the process gas delivered to the domestic water heat exchanger and the heating water heat exchanger.

2. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 1, characterized in that, The intermediate control module includes: The first control module is configured with three initial supply modes, which can control the waste heat recovery module to operate in a corresponding initial supply mode according to the actual heating peak period. The second control module includes a sub-determination module, which can control the actual delivery status of the domestic water heat exchange module and the heating water heat exchange module according to the actual water usage in the living area.

3. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 2, characterized in that, The three initial supply methods are domestic water priority mode, heating water priority mode, and normal supply mode, wherein: The domestic water priority mode means that during the non-heating season, the intermediate control module will control the process gas to be preferentially supplied to the domestic water heat exchange module through the first control module. The heating water priority mode means that during peak heating periods, the intermediate control module will control the process gas to be preferentially supplied to the heating water heat exchange module through the first control module. The normal supply mode is as follows: during the normal heating season, the intermediate control module will control the process gas to be supplied to the domestic water heat exchange module and the heating water heat exchange module at the same flow rate through the first control module.

4. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 3, characterized in that, Low-pressure heating steam is also supplied to one end of the domestic water heat exchange module and the heating water heat exchange module to provide additional heating for the domestic water heat exchange module and / or the heating water heat exchange module.

5. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 4, characterized in that, The sub-determination module is a flow rate determination sub-module. The flow rate determination sub-module can determine the actual water usage by determining the water flow rate at the domestic water heat exchange module and the heating water heat exchange module.

6. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 5, characterized in that, The flow determination submodule includes: A flow monitoring device is installed at the inlet or outlet of the domestic water heat exchange module and the heating water heat exchange module to collect the actual water flow rate passing through the domestic water heat exchange module or the heating water heat exchange module per unit time. The first determination submodule is connected to the flow monitor and is equipped with a preset determination flow rate, which is used to determine the actual water flow rate collected.

7. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 6, characterized in that, The first determination submodule can determine the actual water flow rate at the domestic water heat exchange module or the heating water heat exchange module in the current mode through the preset determination flow rate, so as to control the actual flow rate of process gas at each heat exchange module. The preset determination flow rate includes a preset domestic water flow rate and a preset heating water flow rate. The determination process is as follows: If the actual water flow rate at the domestic water heat exchange module in the current mode is greater than the preset domestic water flow rate, and the actual water flow rate at the heating water heat exchange module in the current mode is less than or equal to the preset heating water flow rate, then the intermediate control module will increase the flow rate of process gas delivered to the domestic water heat exchange module through the first control module. If the actual water flow rate at the heating water heat exchange module in the current mode is greater than the preset heating water flow rate, and the actual water flow rate at the domestic water heat exchange module is less than or equal to the preset domestic water flow rate, then the intermediate control module will increase the flow rate of process gas delivered to the heating water heat exchange module through the first control module. If the actual water flow rate at the domestic water heat exchange module in the current mode is greater than the preset domestic water flow rate, and the actual water flow rate at the heating water heat exchange module is also greater than the preset heating water flow rate, then the intermediate control module will increase the input flow rate of the low-pressure heating steam into the two heat exchange modules through the first control module.

8. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 4, characterized in that, The determination submodule is a temperature difference determination submodule. The determination submodule can determine the actual water usage by determining the actual temperature difference between the domestic water heat exchange module and the heating water heat exchange module within a unit time. The temperature difference determination submodule includes: A temperature monitoring instrument is installed on the domestic water heat exchange module and the heating water heat exchange module to collect the actual temperature difference at the domestic water heat exchange module or the heating water heat exchange module per unit time. The second determination submodule is connected to the temperature monitor and is equipped with a preset determination temperature difference, which is used to determine the actual temperature difference collected.

9. The system for recovering and utilizing waste heat from the end-of-pipe shift gas of the shift process system according to claim 8, characterized in that, The second determination submodule can determine the actual temperature difference at the domestic water heat exchange module or the heating water heat exchange module through the preset determination temperature difference, so as to control the actual flow rate of process gas at each heat exchange module. The preset determination temperature difference includes a preset domestic water temperature difference and a preset heating water temperature difference. The determination process is as follows: If the actual temperature difference at the domestic water heat exchange module in the current mode is greater than the preset domestic water temperature difference, and the actual temperature difference at the heating water heat exchange module is less than or equal to the preset heating water temperature difference, then the intermediate control module will increase the flow rate of the process gas delivered to the domestic water heat exchange module through the first control module. If the actual temperature difference at the heating water heat exchange module in the current mode is greater than the preset heating water temperature difference, and the actual temperature difference at the domestic water heat exchange module is less than or equal to the preset domestic water constant temperature difference, then the intermediate control module will increase the flow rate of the process gas delivered to the heating water heat exchange module through the first control module. If the actual temperature difference at the domestic water heat exchange module in the current mode is greater than the preset domestic water temperature difference, and the actual temperature difference at the heating water heat exchange module is also greater than the preset heating water temperature difference, then the intermediate control module will increase the input flow rate of the low-pressure heating steam into the two heat exchange modules through the first control module.

10. The method for recovering and utilizing the waste heat of the terminal converter gas in a converter process system according to any one of claims 1-9, characterized in that, include: Step S1: Introduce the process gas after multi-stage separation into the demineralized water heat exchanger for preliminary heat exchange and cooling. Step S2: Select the operating mode through the intermediate control module according to the current season and heating demand. The operating modes include domestic water priority mode, heating water priority mode or normal supply mode. Step S3: The process gas after heat exchange in the demineralized water heat exchanger is delivered to the domestic water heat exchange module and the heating water heat exchange module respectively through the intermediate control module according to the initial distribution ratio of the selected operating mode. Step S4: Real-time acquisition of the actual water flow rate or actual temperature difference passing through the domestic water heat exchange module and the heating water heat exchange module through the flow rate determination submodule and / or temperature difference determination submodule; Step S5: Compare the collected actual values ​​with the preset judgment flow rate or preset judgment temperature difference in the corresponding mode, and dynamically adjust the process gas flow rate delivered to each heat exchange module according to the comparison results. If the actual demand exceeds the corresponding preset value, then start or increase the input flow rate of low-pressure heating steam for auxiliary heating; Step S6: The process gas that has been cooled by heat exchange in the waste heat recovery module is combined and sent to the shift gas water cooler for final cooling, and then sent to the ammonia washing tower for further processing.

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