Oil sludge pyrolysis gas and flue gas double heat source waste heat recovery method and system

Abstract

This invention relates to the field of solid waste pyrolysis waste heat recovery technology, specifically a method and system for recovering and utilizing waste heat from two heat sources: pyrolysis gas and flue gas from oil sludge. The method includes: collecting flow rate, temperature, and composition data of the high-temperature pyrolysis gas and high-temperature flue gas generated from oil sludge pyrolysis; inputting the collected data into a collaborative heat exchange control algorithm based on the temperature response characteristics of the heat exchange medium; and calculating a dynamic distribution scheme for the flow rate of the two heat exchange media. The flow rates of the two heat exchange media are adjusted in real time to achieve heat recovery from both heat sources in designated areas, producing high-temperature heat exchange media to drive equipment for work or heat supply. The low-temperature media after heat exchange is collected and refluxed, regenerated through impurity filtration and physical parameter adjustment, and then re-transported to the heat exchange channel to form a closed-loop cycle. This scheme can adapt to dynamic changes in the operating conditions of the two heat sources, balance the operating status of the two heat exchange channels, reduce heat loss, and achieve efficient collaborative recovery of waste heat from both heat sources in oil sludge pyrolysis.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology from solid waste pyrolysis, and in particular to a method and system for recovering and utilizing waste heat from both pyrolysis gas and flue gas in oil sludge. Background Technology

[0002] The pyrolysis process of oil sludge continuously generates high-temperature pyrolysis gas and high-temperature flue gas. These two types of media store a large amount of waste heat resources, and waste heat recovery is a key link in the resource utilization of oil sludge in the process of harmless disposal. Existing waste heat recovery operations for oil sludge pyrolysis generally adopt an integrated and unified heat exchange mode, using the same heat exchange medium to transport the two heat sources, pyrolysis gas and flue gas, and completing the entire heat exchange operation at a fixed flow rate.

[0003] Existing heat exchange operation modes do not differentiate between the operating conditions of the two heat sources. The flow rate, temperature, and composition parameters of pyrolysis gas and flue gas fluctuate continuously during production operations, and the fixed medium supply method cannot adapt to the dynamically changing heat exchange conditions of the two heat sources. Conventional technologies do not incorporate the temperature response characteristics of the heat exchange medium itself into the design of control logic, and lack a distribution mechanism for integrating and calculating multi-dimensional operating condition data. During synchronous heat exchange with two heat sources, the heat absorption state cannot be balanced and unified.

[0004] Traditional waste heat recovery systems lack a dual-channel independent flow regulation structure, resulting in an inability to match the heat output rhythm of the two high-temperature heat sources with the heat exchange operation rhythm. This leads to insufficient waste heat absorption and significant heat loss. Furthermore, the overall heat exchange medium distribution method is simplistic, making it difficult to establish a stable circulation system suitable for both heat sources. To address these technical shortcomings, a multi-parameter collaborative calculation and control system, coupled with a dual-channel independent flow regulation structure, is needed to meet the operational requirements of stable waste heat recovery from the dual heat sources of oil sludge pyrolysis. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and to propose a method and system for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas, comprising: Obtain flow rate, temperature, and composition data of the high-temperature pyrolysis gas and high-temperature flue gas generated during the pyrolysis of oil sludge; The flow rate, temperature, and composition data are input into the collaborative heat exchange control algorithm to calculate the dynamic distribution scheme of the medium flow rate in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel. The collaborative heat exchange control algorithm is established based on the temperature response characteristics of the heat exchange medium. According to the aforementioned dynamic distribution scheme for medium flow, the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel are dynamically adjusted so that the heat exchange medium recovers heat in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel respectively, thereby generating a high-temperature heat exchange medium. The high-temperature heat exchange medium is introduced into the heat energy utilization device to drive the heat energy utilization device to perform work or supply heat to the outside. After the low-temperature heat exchange medium is discharged from the heat energy utilization device, the low-temperature heat exchange medium is collected and summarized to form a heat exchange medium reflux. The heat exchange medium reflux is subjected to impurity filtration and physical parameter adjustment to generate a regenerated heat exchange medium; The regenerated heat exchange medium is redistributed to the pyrolysis gas heat exchange channel and the flue gas heat exchange channel to form a closed waste heat recovery cycle.

[0007] As a further aspect of the present invention, the collaborative heat exchange control algorithm is established based on the temperature response characteristics of the heat exchange medium, and its working principle includes: A dynamic model of heat balance between pyrolysis gas and flue gas is established. The dynamic model of heat balance uses the real-time pyrolysis gas flow rate, pyrolysis gas temperature, flue gas flow rate, flue gas temperature, and the current inlet temperature of the heat exchange medium as input variables. Based on the aforementioned dynamic heat balance model, the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel are calculated under a specified outlet temperature target. A heat exchange medium temperature response correction factor is introduced, which is determined by the specific heat capacity, viscosity, and historical average flow rate of the heat exchange medium in the corresponding heat exchange channel. Using the heat exchange medium temperature response correction factor, the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel are corrected respectively, so as to obtain the target value of the medium flow rate of the pyrolysis gas heat exchange channel and the target value of the medium flow rate of the flue gas heat exchange channel. Based on the current total flow limit of the heat exchange medium system, the target flow values ​​of the medium in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are normalized to generate an executable dynamic allocation scheme for the current flow rate. The executable dynamic allocation scheme includes the specific values ​​of the first flow rate and the second flow rate of the heat exchange medium.

[0008] As a further aspect of the present invention, the dynamic adjustment of the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel, so that the heat exchange medium recovers heat in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel respectively, to generate a high-temperature heat exchange medium, includes: A first flow regulating valve is installed on the inlet pipe of the pyrolysis gas heat exchange channel, and a second flow regulating valve is installed on the inlet pipe of the flue gas heat exchange channel. The first and second flow rate settings of the heat exchange medium corresponding to the current moment are extracted from the dynamic distribution scheme of the medium flow rate. The first flow rate set value of the heat exchange medium is sent to the first flow regulating valve to control the opening of the first flow regulating valve so that the actual flow rate through the pyrolysis gas heat exchange channel matches the first flow rate set value of the heat exchange medium. The second flow rate set value of the heat exchange medium is sent to the second flow regulating valve to control the opening of the second flow regulating valve so that the actual flow rate through the flue gas heat exchange channel matches the second flow rate set value of the heat exchange medium. In the pyrolysis gas heat exchange channel, the heat exchange medium with a flow rate of the first flow rate set value of the heat exchange medium is subjected to non-contact countercurrent heat exchange with the high temperature pyrolysis gas, absorbing the sensible heat of the pyrolysis gas and generating the first high temperature heat exchange medium. In the flue gas heat exchange channel, the heat exchange medium with a flow rate of the second flow rate set value of the heat exchange medium is subjected to non-contact countercurrent heat exchange with the high temperature flue gas, absorbing the sensible heat of the flue gas and generating a second high temperature heat exchange medium. The first high-temperature heat exchange medium and the second high-temperature heat exchange medium are combined to generate a combined high-temperature heat exchange medium.

[0009] As a further aspect of the present invention, the high-temperature heat exchange medium is introduced into the heat energy utilization device to drive the heat energy utilization device to perform work or supply heat to the outside, including: The combined high-temperature heat exchange medium is introduced into the tube side of the steam generator to heat the water in the shell side of the steam generator and generate saturated steam or superheated steam. The generated steam is introduced into a steam turbine to drive the turbine rotor to rotate. The turbine rotor is connected to a generator to convert rotational mechanical energy into electrical energy output. The exhaust steam discharged from the turbine is introduced into the condenser, where it is condensed into condensate. The condensate is pressurized by the feedwater pump and sent back to the shell side of the steam generator to complete the steam power cycle. After the water is heated to generate steam, the temperature of the heat exchange medium discharged from the tube side of the steam generator decreases, forming the low-temperature heat exchange medium.

[0010] As a further aspect of the present invention, the heat exchange medium reflux is subjected to impurity filtration and physical parameter adjustment to generate a regenerated heat exchange medium, including: The low-temperature heat exchange medium is fed into a multi-stage filtration device to remove solid particulate impurities and droplet impurities carried therein in sequence. The composition of the filtered low-temperature heat exchange medium was analyzed, and its acidity, alkalinity and conductivity were detected. Based on the detection results of pH and conductivity, chemical agents are added to the filtered low-temperature heat exchange medium to adjust its pH to a preset neutral range and its conductivity to below a preset threshold, thereby generating a chemically stable heat exchange medium. The chemically stable heat exchange medium is pressurized and its temperature is finely adjusted to increase its pressure to the circulating working pressure and stabilize its temperature within the preset regeneration medium temperature range to generate the regenerated heat exchange medium.

[0011] As a further aspect of the present invention, the pressurization and temperature fine-tuning treatment of the chemically stable heat exchange medium includes: A chemically stable heat exchange medium is introduced into a circulating pump, and the pressure of the heat exchange medium is increased to the circulating working pressure by the circulating pump. The circulating working pressure must meet the requirements of the heat exchange medium overcoming flow resistance and maintaining good heat transfer in the heat exchange channel. Temperature-regulating water is introduced from an external low-temperature heat source or the low-temperature circulating water in the plant area. Before the pressurized heat exchange medium enters the heat exchange channel, the temperature-regulating water and the pressurized heat exchange medium exchange heat in a mixing device. By controlling the flow rate of the temperature-regulating water, the temperature of the mixed heat exchange medium is adjusted so that it falls near the midpoint of the preset regeneration medium temperature range. The heat exchange medium, after temperature fine-tuning, is delivered to the inlet of the heat exchange medium distribution manifold.

[0012] As a further aspect of the present invention, the method further includes pretreatment of the high-temperature pyrolysis gas and the high-temperature flue gas, including: Before the pyrolysis gas enters the pyrolysis gas heat exchange channel, the high-temperature pyrolysis gas is subjected to cyclone separation and deep filtration to remove tar droplets and solid ash particles entrained in the pyrolysis gas. Before the flue gas enters the flue gas heat exchange channel, the high-temperature flue gas is sprayed to cool down and electrostatically removed to reduce the flue gas temperature to the allowable inlet temperature range of the heat exchange equipment and remove dust particles from the flue gas. The temperature and cleanliness of the pretreated pyrolysis gas and flue gas are monitored in real time. When the temperature or cleanliness exceeds the allowable range, an alarm is triggered and the operating parameters of the pretreatment process are adjusted.

[0013] As a further aspect of the present invention, the real-time monitoring of the temperature and cleanliness indicators of the pretreated pyrolysis gas and flue gas includes: A resistance thermometer and an online turbidity analyzer are installed on the pipeline after the pyrolysis gas pretreatment to continuously measure the temperature and turbidity of the pretreated pyrolysis gas. An infrared thermometer and a laser dust concentration monitor are installed on the pipeline after flue gas pretreatment to continuously measure the temperature and dust concentration of the pretreated flue gas, respectively. The measured temperature, turbidity, temperature, and dust concentration of the pretreated pyrolysis gas are transmitted to the central controller. The central controller is preset with upper limit thresholds for pyrolysis gas temperature, pyrolysis gas turbidity, flue gas temperature, and flue gas dust concentration. The central controller compares the received measurement values ​​with the corresponding preset thresholds in real time. When any measurement value continuously exceeds its corresponding preset threshold for a preset duration, it is determined that the indicator exceeds the allowable range and an alarm signal is triggered.

[0014] As a further aspect of the present invention, the heat exchange medium temperature response correction factor is used to correct the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel, respectively, to obtain the target flow rate values ​​of the medium for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel, including: Obtain the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel, calculated by the aforementioned dynamic heat balance model. Query the specific heat capacity and viscosity parameters of the current heat exchange medium from the preset physical property parameter database; Extract the historical average flow rate of the heat exchange medium in the pyrolysis gas heat exchange channel and the historical average flow rate in the flue gas heat exchange channel within the preset statistical period from the historical operation database. Based on the specific heat capacity, viscosity, and historical average flow rate of the current heat exchange medium in the pyrolysis gas heat exchange channel, the heat exchange medium temperature response correction factor in the pyrolysis gas heat exchange channel is calculated. Based on the specific heat capacity, viscosity, and historical average flow velocity of the current heat exchange medium in the flue gas heat exchange channel, the heat exchange medium temperature response correction factor in the flue gas heat exchange channel is calculated. The target value of the heat exchange medium flow rate in the pyrolysis gas heat exchange channel is calculated by multiplying the heat exchange medium temperature response correction factor in the pyrolysis gas heat exchange channel by the theoretical flow rate of the heat exchange medium required in the pyrolysis gas heat exchange channel. The target value of the medium flow rate in the flue gas heat exchange channel is calculated by multiplying the temperature response correction factor of the heat exchange medium in the flue gas heat exchange channel by the theoretical flow rate of the heat exchange medium required in the flue gas heat exchange channel. The target flow rate of the medium in the pyrolysis gas heat exchange channel and the target flow rate of the medium in the flue gas heat exchange channel are output to the normalization processing step.

[0015] As a further aspect of the present invention, the present invention also includes a dual-heat-source waste heat recovery and utilization system for sludge pyrolysis gas and flue gas. The system includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the dual-heat-source waste heat recovery and utilization method for sludge pyrolysis gas and flue gas as described above.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows: A collaborative heat exchange control algorithm is constructed based on the temperature response characteristics of the heat exchange medium. Real-time multi-dimensional operational data on the flow rate, temperature, and composition of pyrolysis gas and flue gas during the sludge pyrolysis process are collected. The algorithm generates a medium flow distribution scheme adapted to the dual-heat-source operating state through real-time calculations. The synchronous acquisition and calculation of multi-dimensional on-site operating data closely matches the dynamic fluctuations in sludge pyrolysis production, the actual real-time heat generation of different heat sources, and the inherent laws governing temperature changes in the heat exchange medium. This process mitigates the negative impact of operational fluctuations on the heat exchange process, ensuring that the heat exchange parameter allocation logic aligns with the actual on-site heat exchange operating conditions.

[0017] Two independent control paths are established: a pyrolysis gas heat exchange channel and a flue gas heat exchange channel. The flow volume of the heat exchange medium in each path is adjusted separately, allowing for flexible adjustment of the medium transport volume based on the heat generation characteristics of different heat sources. This split-channel control system adapts to the differentiated heat release rhythms of the two high-temperature media, coordinates the heat exchange rhythms within different heat exchange channels, balances the heat exchange process of different heat sources, and reduces heat loss during transfer. The dual-channel independent control operation enables both high-temperature heat sources to participate simultaneously in the waste heat recovery process, improving the smoothness of the closed-loop heat exchange cycle and expanding the scope of recovery and utilization of pyrolysis by-product heat sources. Attached Figure Description

[0018] Figure 1 The flowchart is a process for the waste heat recovery and utilization method of dual heat sources of sludge pyrolysis gas and flue gas according to the present invention. Figure 2 A flowchart for the collaborative heat exchange control algorithm based on the temperature response characteristics of the heat exchange medium; Figure 3 A flowchart for introducing a high-temperature heat exchange medium into a heat energy utilization device to drive external work or heat supply. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] See Figure 1 The present invention discloses a dual-heat-source waste heat recovery and utilization method for sludge pyrolysis gas and flue gas. The implementation process is as follows: During system operation, the flow rate, temperature, and composition data of the high-temperature pyrolysis gas generated in the sludge pyrolysis process section and the high-temperature flue gas generated to provide heat for pyrolysis are acquired in real time. These data are collected through flow meters, temperature sensors, and gas analyzers installed on corresponding pipelines. The acquired real-time flow rate, temperature, and composition data are transmitted to the control system and input into a preset collaborative heat exchange control algorithm. This algorithm is established based on the temperature response characteristics of the heat exchange medium and calculates a dynamic distribution scheme for the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel under the current operating conditions. Based on this dynamic distribution scheme, the control system drives the corresponding regulating mechanism to dynamically adjust the flow rate of the heat exchange medium entering the pyrolysis gas heat exchange channel and the flue gas heat exchange channel. The heat exchange medium, such as pressurized water or thermal oil, undergoes non-contact heat exchange with high-temperature pyrolysis gas in the pyrolysis gas heat exchange channel and with high-temperature flue gas in the flue gas heat exchange channel, recovering its sensible heat and thus increasing its own temperature to generate a high-temperature heat exchange medium. This high-temperature heat exchange medium is then drawn out and introduced into subsequent thermal energy utilization devices, such as steam generators or organic working fluid evaporators. In these devices, the high-temperature heat exchange medium releases heat, driving the device to perform work or provide heat. Work can manifest as driving a steam turbine to generate electricity, while heat can manifest as providing hot water or steam to process or domestic facilities. After releasing heat, the temperature of the heat exchange medium decreases, and it is discharged from the thermal energy utilization device, forming a low-temperature heat exchange medium. The system includes a manifold to collect the low-temperature heat exchange medium discharged from the thermal energy utilization device and other possible branches, forming a heat exchange medium return stream. This return stream enters a regeneration treatment unit, where it undergoes impurity filtration and physical parameter adjustment. Impurity filtration removes solid impurities and droplets that may be carried during the circulation process; physical parameter adjustment includes adjusting parameters such as pressure, temperature, and pH to meet the requirements for re-entry into the heat exchange channel, thereby generating a regenerated heat exchange medium. The regenerated heat exchange medium is then redistributed to the inlets of the pyrolysis gas heat exchange channel and the flue gas heat exchange channel according to a dynamic distribution scheme through a distribution device, thus forming a complete, closed waste heat recovery cycle system.

[0022] In one embodiment of the present invention, the collaborative heat exchange control algorithm is established based on the temperature response characteristics of the heat exchange medium, and its working principle includes the following steps. (See also...) Figure 2 A dynamic heat balance model for the heat exchange process between pyrolysis gas and flue gas is established. This model uses real-time acquired pyrolysis gas flow rate, pyrolysis gas temperature, flue gas flow rate, flue gas temperature, and the current inlet temperature of the heat exchange medium as input variables. Based on the established dynamic heat balance model, the theoretical flow rates of the heat exchange medium required for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are calculated under a specified outlet temperature target. The algorithm introduces a heat exchange medium temperature response correction factor, which is determined by the specific heat capacity, viscosity, and historical average flow rate of the heat exchange medium in the corresponding heat exchange channel. The theoretical flow rates of the heat exchange medium required for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel, calculated by the dynamic heat balance model, are obtained. The specific heat capacity and viscosity parameters of the currently circulating heat exchange medium are queried from a preset physical property parameter database. The historical average flow rates of the heat exchange medium in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel within a preset statistical period are extracted from the historical operation database.

[0023] Based on the specific heat capacity, viscosity, and historical average flow rate of the current heat exchange medium in the pyrolysis gas heat exchange channel, a heat exchange medium temperature response correction factor in the pyrolysis gas heat exchange channel is calculated. Based on the specific heat capacity, viscosity, and historical average flow rate of the current heat exchange medium in the flue gas heat exchange channel, a heat exchange medium temperature response correction factor in the flue gas heat exchange channel is also calculated. Multiplying this heat exchange medium temperature response correction factor in the pyrolysis gas heat exchange channel by the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel, the target flow rate value for the medium in the pyrolysis gas heat exchange channel is calculated. Finally, multiplying this heat exchange medium temperature response correction factor in the flue gas heat exchange channel by the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel, the target flow rate value for the medium in the flue gas heat exchange channel is calculated. The theoretical flow rates of the heat exchange medium required for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are corrected using the heat exchange medium temperature response correction factor, respectively, to obtain the target flow rates of the heat exchange medium for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel. These target flow rates are then output to the normalization process. Based on the current total flow supply capacity limitation of the entire heat exchange medium circulation system, the control system normalizes the target flow rates of the heat exchange medium for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel, generating an executable dynamic flow allocation scheme for the current moment. This executable dynamic flow allocation scheme includes specific numerical setting instructions for the first and second flow rates of the heat exchange medium.

[0024] In specific implementation, the establishment and working process of the collaborative heat exchange control algorithm is as follows: The collaborative heat exchange control algorithm is established based on the temperature response characteristics of the heat exchange medium. Its working principle includes establishing a dynamic heat balance model of the heat exchange process between pyrolysis gas and flue gas. The dynamic heat balance model uses the real-time acquired pyrolysis gas flow rate, pyrolysis gas temperature, flue gas flow rate, flue gas temperature, and the current inlet temperature of the heat exchange medium as input variables. In an example scenario, the monitored value of the pyrolysis gas flow rate is 1200 standard cubic meters per hour and the monitored value of the pyrolysis gas temperature is 480 degrees Celsius. The monitored value of the flue gas flow rate is 950 standard cubic meters per hour and the monitored value of the flue gas temperature is 620 degrees Celsius. The monitored value of the current inlet temperature of the heat exchange medium is 145 degrees Celsius. These real-time data are transmitted to the central processing unit as input variables of the dynamic heat balance model. Based on the thermal balance dynamic model, the theoretical flow rates of the heat exchange medium required for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are calculated under a specified outlet temperature target. For example, if the specified outlet temperature target of the heat exchange medium is 320 degrees Celsius, the thermal balance dynamic model calculates that the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel is 55 cubic meters per hour, and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel is 42 cubic meters per hour.

[0025] In some embodiments, a heat exchange medium temperature response correction factor is introduced. This factor is determined by the specific heat capacity, viscosity, and historical average flow rate of the heat exchange medium in the corresponding heat exchange channel. The theoretical flow rates of the heat exchange medium required for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel, calculated by the thermal balance dynamic model, are obtained. The specific heat capacity and viscosity parameters of the currently circulating heat exchange medium are queried from a preset physical property parameter database. For example, if the current heat exchange medium is synthetic heat transfer oil, the specific heat capacity query result is 2.3 kJ / kg / Kelvin, and the viscosity query result is 0.75 mPa·s. The historical average flow rates of the heat exchange medium in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel within a preset statistical period are extracted from the historical operation database. The preset statistical period is set to 12 hours. The historical operation database records show that the historical average flow rate in the pyrolysis gas heat exchange channel is 1.15 m / s, and the historical average flow rate in the flue gas heat exchange channel is 0.98 m / s.

[0026] Based on the specific heat capacity, viscosity, and historical average flow rate of the heat exchange medium in the pyrolysis gas heat exchange channel, a temperature response correction factor for the heat exchange medium in the pyrolysis gas heat exchange channel is calculated. Similarly, based on the specific heat capacity, viscosity, and historical average flow rate of the heat exchange medium in the flue gas heat exchange channel, a temperature response correction factor for the heat exchange medium in the flue gas heat exchange channel is calculated. The calculation of the temperature response correction factor is performed using the following formula:

[0027] in: This represents the temperature response correction factor of the heat exchange medium. The specific heat capacity of the heat exchange medium. The dynamic viscosity of the heat exchange medium. Represents the historical average flow velocity of the heat exchange medium within the corresponding heat exchange channel, coefficient ,coefficient ,coefficient The dimensionless constants are pre-calibrated using a system identification method. The target flow rate of the heat exchange medium in the pyrolysis gas heat exchange channel is calculated by multiplying the temperature response correction factor of the heat exchange medium in the pyrolysis gas heat exchange channel by the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel. Similarly, the target flow rate of the heat exchange medium in the flue gas heat exchange channel is calculated by multiplying the temperature response correction factor of the heat exchange medium in the flue gas heat exchange channel by the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel. In specific implementation, based on the queried and extracted data, the temperature response correction factor for the heat exchange medium in the pyrolysis gas heat exchange channel is calculated to be 1.08, and the temperature response correction factor for the heat exchange medium in the flue gas heat exchange channel is calculated to be 0.92. Therefore, the target flow rate of the heat exchange medium in the pyrolysis gas heat exchange channel is 55 cubic meters per hour multiplied by 1.08, which equals 59.4 cubic meters per hour, and the target flow rate of the heat exchange medium in the flue gas heat exchange channel is 42 cubic meters per hour multiplied by 0.92, which equals 38.64 cubic meters per hour.

[0028] Understandably, based on the current total flow limit of the heat exchange medium system, the target flow rates of the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are normalized to generate an executable dynamic flow allocation scheme for the current moment. For example, if the current total flow limit provided by the heat exchange medium circulation pump is 95 cubic meters per hour, and the sum of the target flow rates of the pyrolysis gas heat exchange channel (59.4 cubic meters per hour) and the flue gas heat exchange channel (38.64 cubic meters per hour) is 98.04 cubic meters per hour, exceeding the total flow limit, the normalization process scales the two target values ​​proportionally to a sum equal to 95 cubic meters per hour, generating a set flow rate of 57.5 cubic meters per hour for the pyrolysis gas heat exchange channel and 37.5 cubic meters per hour for the flue gas heat exchange channel. Optionally, the normalization process follows a proportional scaling principle to ensure that the ratio of the allocated flow rates for each channel remains consistent with the target flow rate ratio. In some embodiments, the executable dynamic media flow allocation scheme is output in the form of digital instructions, including a first flow rate setpoint of 57.5 cubic meters per hour and a second flow rate setpoint of 37.5 cubic meters per hour for the heat exchange medium. These values ​​are directly sent to the corresponding flow controllers. It can be understood that the execution of the entire collaborative heat exchange control algorithm is periodic; the central processing unit reads the real-time input variables and performs a complete calculation every 10 seconds to dynamically update the dynamic media flow allocation scheme.

[0029] In one embodiment of the present invention, the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel are dynamically adjusted so that the heat exchange medium recovers heat in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel respectively, generating a high-temperature heat exchange medium. This process is specifically implemented as follows: A first flow regulating valve is installed on the inlet pipe of the pyrolysis gas heat exchange channel, and a second flow regulating valve is installed on the inlet pipe of the flue gas heat exchange channel. The control system parses the set values ​​of the first and second flow rates of the heat exchange medium corresponding to the current moment from the dynamic distribution scheme of the medium flow. The control system sends the set value of the first flow rate of the heat exchange medium to the first flow regulating valve in the form of a control signal, controlling the opening of the first flow regulating valve so that the actual flow rate value flowing through the pyrolysis gas heat exchange channel is fed back through the flow meter and ultimately matches the set value of the first flow rate of the heat exchange medium. The control system sends the second flow rate setpoint of the heat exchange medium to the second flow regulating valve in the form of a control signal, controlling the opening of the second flow regulating valve so that the actual flow rate through the flue gas heat exchange channel matches the second flow rate setpoint of the heat exchange medium. In the pyrolysis gas heat exchange channel, the heat exchange medium with a flow rate adjusted to the first flow rate setpoint of the heat exchange medium undergoes non-contact counter-current heat exchange with the high-temperature pyrolysis gas in the heat exchanger. The heat exchange medium absorbs the sensible heat of the pyrolysis gas, its temperature rises, and a first high-temperature heat exchange medium is generated. In the flue gas heat exchange channel, the heat exchange medium with a flow rate adjusted to the second flow rate setpoint of the heat exchange medium undergoes non-contact counter-current heat exchange with the high-temperature flue gas in another heat exchanger. The heat exchange medium absorbs the sensible heat of the flue gas, its temperature rises, and a second high-temperature heat exchange medium is generated. The first and second high-temperature heat exchange media merge in a shared confluence pipe to generate a merged high-temperature heat exchange medium, which is then transported to the thermal energy utilization device.

[0030] In practical implementation, the specific process of dynamically adjusting the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel, so that the heat exchange medium recovers heat in the pyrolysis gas heat exchange channel and generates a high-temperature heat exchange medium, is as follows: A first flow regulating valve is installed on the inlet pipe of the pyrolysis gas heat exchange channel, and a second flow regulating valve is installed on the inlet pipe of the flue gas heat exchange channel. Both the first and second flow regulating valves are regulating valves equipped with electric positioners, receiving a 4-20 mA current signal from the control system to continuously adjust the opening degree. The control system parses the set values ​​of the first and second flow rates of the heat exchange medium corresponding to the current moment from the dynamic distribution scheme of the medium flow rate. In an example scenario, the dynamic distribution scheme of the medium flow rate outputs a set value of 57.5 cubic meters per hour for the first flow rate of the heat exchange medium and a set value of 37.5 cubic meters per hour for the second flow rate of the heat exchange medium. The control system parses these two values ​​from the scheme and prepares to send them to the corresponding actuators.

[0031] In some embodiments, the control system sends a first flow rate setpoint of the heat exchange medium to a first flow regulating valve in the form of a control signal, controlling the opening of the first flow regulating valve. A first electromagnetic flowmeter installed in the inlet pipe of the pyrolysis gas heat exchange channel monitors the actual flow rate of the heat exchange medium flowing through the pipe in real time and feeds the signal back to the control system. The control system compares the feedback actual flow rate value with the first flow rate setpoint of the heat exchange medium, calculates and outputs a new control signal to the first flow regulating valve using a proportional-integral-differential algorithm, and adjusts its opening so that the actual flow rate flowing through the pyrolysis gas heat exchange channel matches the first flow rate setpoint of the heat exchange medium. The control system sends a second flow rate setpoint of the heat exchange medium to a second flow regulating valve in the form of a control signal, controlling the opening of the second flow regulating valve. A second electromagnetic flowmeter installed in the inlet pipe of the flue gas heat exchange channel provides actual flow feedback. The control system uses closed-loop control to match the actual flow rate flowing through the flue gas heat exchange channel with the second flow rate setpoint of the heat exchange medium. It can be understood that the closed-loop control logic of flow regulation can be characterized by the following relationship:

[0032] in: This represents the flow regulation amount calculated to eliminate flow deviation. This represents the setpoint for the heat exchange medium flow rate. This represents the actual flow rate of the heat exchange medium. This represents the preset proportional coefficient within the control system. This represents the preset integral coefficient within the control system. Represents the preset differential coefficients within the control system. Representing time, this flow rate adjustment is converted into a command to change the valve opening.

[0033] In the pyrolysis gas heat exchange channel, the heat exchange medium with a flow rate adjusted to the first set value of the heat exchange medium undergoes non-contact countercurrent heat exchange with the high-temperature pyrolysis gas in the pyrolysis gas heat exchanger. The heat exchange medium flows in the tube side, while the high-temperature pyrolysis gas flows in the shell side in the opposite direction. The heat exchange medium absorbs the sensible heat of the pyrolysis gas, and its temperature rises, generating the first high-temperature heat exchange medium. In the example, the heat exchange medium with a flow rate of 57.5 cubic meters per hour and an inlet temperature of 145 degrees Celsius reaches an outlet temperature of 315 degrees Celsius after heat exchange. In the flue gas heat exchange channel, the flow rate of the heat exchange medium, adjusted to a second set value, undergoes non-contact counter-current heat exchange with the high-temperature flue gas within the flue gas heat exchanger. The heat exchange medium flows in the tube side, while the high-temperature flue gas flows counter-currently in the shell side. The heat exchange medium absorbs the sensible heat of the flue gas, increasing its temperature and generating a second high-temperature heat exchange medium. In the example, a heat exchange medium with a flow rate of 37.5 cubic meters per hour and an inlet temperature of 145 degrees Celsius reaches an outlet temperature of 325 degrees Celsius after heat exchange. Optionally, the non-contact counter-current heat exchange can be achieved using a shell-and-tube heat exchanger or a plate heat exchanger. The pyrolysis gas and flue gas flow through the shell side, while the heat exchange medium flows through the tube side, exchanging heat through the metal walls without mixing. The first and second high-temperature heat exchange media merge in a shared confluence pipe to form a combined high-temperature heat exchange medium. The temperature of the combined high-temperature heat exchange medium is calculated from the flow rates and temperatures of the two media through heat balance. In this example, the flow rate of the combined high-temperature heat exchange medium is 95 cubic meters per hour, and the temperature is approximately 319 degrees Celsius. In some embodiments, temperature and pressure sensors are installed on the confluence pipe to monitor the operating parameters of the combined high-temperature heat exchange medium. It is understood that the generated combined high-temperature heat exchange medium is transported to a heat energy utilization device, such as the inlet of a steam generator. Optionally, before each high-temperature heat exchange medium merges, its pipeline is also independently equipped with a temperature monitoring point to monitor the outlet temperature of each individual heat exchange channel in real time and compare it with a preset safety threshold to prevent overheating.

[0034] In one embodiment of the present invention, the high-temperature heat exchange medium is introduced into a heat energy utilization device to drive the heat energy utilization device to perform work or supply heat to the outside world. One implementation method includes the following steps. See below. Figure 3The combined high-temperature heat exchange medium is introduced into the tube side of the steam generator. The high-temperature heat exchange medium flows within the tube side and releases heat, heating the water in the shell side of the steam generator to produce saturated steam or superheated steam. The generated steam is drawn from the steam generator and introduced into the turbine inlet. The steam expansion drives the turbine rotor to rotate. The turbine rotor is coaxially connected to the generator, thereby converting rotational mechanical energy into electrical energy output. The low-pressure exhaust steam discharged from the turbine is introduced into the condenser, where it exchanges heat with cooling water and condenses into condensate. The condensate is pressurized by a feedwater pump and sent back to the shell side of the steam generator to replenish the consumed water and complete the steam power cycle. After heating the water to generate steam, the heat exchange medium discharged from the tube side of the steam generator cools down due to the release of heat, forming the low-temperature heat exchange medium. This low-temperature heat exchange medium is sent to the subsequent return and collection pipeline.

[0035] In practical implementation, the process of introducing the combined high-temperature heat exchange medium into the heat energy utilization device and driving it to perform external work is as follows: The combined high-temperature heat exchange medium is introduced into the tube side of the steam generator. The combined high-temperature heat exchange medium flows within the tube side of the steam generator and releases heat, heating the water in the shell side of the steam generator to produce saturated steam or superheated steam. In an example scenario, the combined high-temperature heat exchange medium enters the tube side of the steam generator at a flow rate of 95 cubic meters per hour and a temperature of 319 degrees Celsius. The feedwater pressure in the shell side is maintained at 4.0 MPa. After releasing heat, the temperature of the high-temperature heat exchange medium drops to 161 degrees Celsius and is discharged from the tube side of the steam generator. The water in the shell side is heated and converted into saturated steam with a pressure of 4.0 MPa and a temperature of 250 degrees Celsius. The steam output can be obtained through measurement and calculation. The generated steam is drawn from the steam generator and introduced into the inlet of the steam turbine. The steam expands and performs work within the steam turbine, driving the turbine rotor to rotate. The turbine rotor and the generator are rigidly connected through a coupling, thereby converting rotational mechanical energy into electrical energy output. Low-pressure exhaust steam from the turbine is introduced into the condenser, where it undergoes indirect heat exchange with circulating cooling water, condensing into condensate. The condensate is then pressurized by a feedwater pump and returned to the shell side of the steam generator to replenish the water consumed in evaporation, completing the steam power cycle. After heating the water to generate steam, the heat exchange medium discharged from the tube side of the steam generator cools down due to heat release, becoming a low-temperature heat exchange medium. This low-temperature heat exchange medium is then sent to the subsequent return collection line. The heat exchange process within the steam generator follows a heat balance relationship, the basic equation of which can be expressed as:

[0036] in: This represents the total heat exchange in the steam generator. Represents the mass flow rate of the high-temperature heat exchange medium. The specific heat capacity at constant pressure represents the heat transfer medium at high temperatures. This represents the inlet temperature of the high-temperature heat exchange medium entering the tube side of the steam generator. This represents the outlet temperature of the high-temperature heat exchange medium leaving the tube side of the steam generator. This represents the mass flow rate of steam produced by the steam generator. Specific enthalpy, representing the output steam. This represents the specific enthalpy of the feedwater entering the shell side of the steam generator. In some embodiments, the steam parameters generated by the steam generator and the turbine operating status can be monitored. For a comparison of the operating parameters, refer to Table 1: Table 1: Operating Parameters of Thermal Energy Utilization System

[0037] In practice, the turbine's exhaust pressure is maintained at a vacuum state by the condenser, with the absolute pressure inside the condenser maintained at 8 kPa, corresponding to a saturation temperature of approximately 41.5 degrees Celsius. Exhaust steam condenses at this temperature and pressure. Condensate is pumped by a condensate pump, passes through a low-pressure heater and deaerator, and is then pressurized by a feedwater pump to a pressure higher than the steam generator's operating pressure before being returned to the steam generator's shell side. It can be understood that the temperature of the low-temperature heat exchange medium discharged from the steam generator's tube side is closely related to the steam generator's design and operating conditions; the temperature of the low-temperature heat exchange medium is the input condition for subsequent regeneration processes. Optionally, the steam generator can be designed as a horizontal natural circulation boiler, with the high-temperature heat exchange medium flowing inside the tubes and water heated and naturally circulating outside the tubes. In some embodiments, the turbine can be a single-stage back-pressure type or a condensing type, the specific selection depending on the plant's balance between electricity and process steam demands. Exhaust steam from the turbine is introduced into the condenser, which employs a surface heat exchange structure. Circulating cooling water flows inside the tubes, while the exhaust steam condenses outside the tubes. The condensate collects in the condenser's hot well. It is understandable that the efficiency of the entire steam power cycle is affected by multiple factors, including the inlet temperature of the high-temperature heat exchange medium, steam parameters, and the condenser vacuum level. Optionally, a main steam valve and regulating valve are installed on the pipeline before the steam enters the turbine to control the steam flow and ensure system safety. A turning gear is installed between the turbine and the generator to rotate the rotor at low speed before startup and after shutdown.

[0038] In one embodiment of the present invention, the heat exchange medium reflux is subjected to impurity filtration and physical parameter adjustment to generate regenerated heat exchange medium. This process includes the following operations: The collected low-temperature heat exchange medium is fed into a multi-stage filtration device, which sequentially includes coarse filtration and fine filtration units to remove solid particulate impurities and droplet impurities carried therein. The filtered low-temperature heat exchange medium is subjected to online component analysis to detect its pH and conductivity. Based on the detection results of pH and conductivity, chemical agents such as acid-base regulators and scale inhibitors are added to the filtered low-temperature heat exchange medium through a metering pump to adjust its pH to a preset neutral range and its conductivity to below a preset threshold, generating a chemically stable heat exchange medium. The chemically stable heat exchange medium is then pressurized and its temperature is finely adjusted. The pressurization process specifically involves introducing the chemically stable heat exchange medium into a circulation pump, which increases the pressure of the heat exchange medium to the circulating working pressure. The circulating working pressure must meet the requirements of the heat exchange medium overcoming flow resistance and maintaining good heat transfer within the heat exchange channel. The temperature fine-tuning process involves introducing temperature-regulating water from an external low-temperature heat source or the plant's low-temperature circulating water system. Before the pressurized heat exchange medium enters the heat exchange channel, the temperature-regulating water and the pressurized heat exchange medium exchange heat in a mixing device or plate heat exchanger. By controlling the flow rate of the temperature-regulating water, the temperature of the mixed heat exchange medium is adjusted to fall near the midpoint of a preset regeneration medium temperature range. After pressurization and temperature fine-tuning, the regeneration heat exchange medium that meets the circulation requirements is generated. The temperature-fine-tuned heat exchange medium is then transported to the inlet of the heat exchange medium distribution manifold, ready for a new round of distribution and circulation.

[0039] In practice, the process of filtering impurities and adjusting physical parameters of the recirculated heat exchange medium to generate regenerated heat exchange medium includes the following operations: The collected low-temperature heat exchange medium is sent to a multi-stage filtration device, which sequentially includes a coarse filtration unit and a fine filtration unit. The coarse filtration unit uses a 100-mesh basket filter to remove large solid particles carried in the low-temperature heat exchange medium. The fine filtration unit uses a bag filter or cartridge filter with an absolute accuracy of 10 micrometers to further remove fine particles and droplets in the low-temperature heat exchange medium. The filtered low-temperature heat exchange medium is then subjected to online composition analysis. Its acidity / alkalinity is detected by a pH sensor installed on the pipeline, and its conductivity is detected by a conductivity meter. Based on the test results of pH and conductivity, chemical agents are added to the filtered low-temperature heat exchange medium. For example, when the pH is detected to be weakly acidic, sodium hydroxide solution is added through a metering pump to adjust the pH to the preset neutral range of 7.0 to 8.5. When the conductivity exceeds the preset threshold of 1500 microsieverts per centimeter, a scale inhibitor and dispersant is added through a metering pump to adjust the conductivity to below the preset threshold, thereby generating a chemically stable heat exchange medium.

[0040] In some embodiments, the chemically stable heat exchange medium undergoes pressurization and temperature fine-tuning. Pressurization specifically involves introducing the chemically stable heat exchange medium into a circulating pump, which can be a centrifugal water pump or a positive displacement pump. The circulating pump increases the pressure of the heat exchange medium to the circulating working pressure, which must meet the requirements for the heat exchange medium to overcome flow resistance and maintain good heat transfer within the heat exchange channel. In one example, the circulating working pressure is set to 1.6 MPa. Temperature fine-tuning specifically involves introducing temperature-regulating water from an external low-temperature heat source or the plant's low-temperature circulating water system. Before the pressurized heat exchange medium enters the heat exchange channel, the temperature-regulating water and the pressurized heat exchange medium undergo indirect heat exchange in a plate heat exchanger. By controlling the opening of a regulating valve installed on the temperature-regulating water pipeline, the flow rate of the temperature-regulating water is controlled, adjusting the temperature of the mixed heat exchange medium to fall near the midpoint of a preset regeneration medium temperature range. The preset regeneration medium temperature range is 130°C to 150°C, with a midpoint of 140°C. After pressurization and temperature fine-tuning, a regenerated heat exchange medium meeting circulation requirements is generated. Finally, the temperature-fine-tuned heat exchange medium is delivered to the inlet of the heat exchange medium distribution manifold. The amount of chemical reagent added is calculated based on the deviation between the real-time detected pH value and the target value. The addition control relationship can be characterized by the following formula:

[0041] in: This represents the volumetric flow rate of the acid or alkali reagent that needs to be added. This represents the current value of the acidity / alkalinity of the heat exchange medium as monitored online. This represents the preset target pH value. The reaction coefficient represents the response performance related to the buffering capacity of the heat exchange medium. The volumetric flow rate of the heat exchange medium flowing through the dosing point. This represents the actual concentration of the added acid or alkali. The control system calculates and adjusts the metering pump's dosage based on this relationship. For specific implementation details regarding the changes in key parameters of the heat exchange medium before and after regeneration, please refer to Table 2. Table 2: Comparison of Example Parameters in Heat Exchange Medium Regeneration Process

[0042] It is understandable that the coarse filtration unit in a multi-stage filtration system needs regular cleaning, and the filter bags or cartridges of the fine filtration unit need regular replacement to maintain filtration efficiency. Online component analysis instruments need regular calibration to ensure the accuracy of test results. Optionally, the chemical reagent addition point is located on the pipeline after the filtration unit and before the circulating pump to ensure thorough mixing of the reagent and the heat exchange medium. The head of the circulating pump is selected based on the calculated pipeline resistance of the entire heat exchange medium circulation system to ensure that the regenerated heat exchange medium can be delivered to the highest point of the system. It is understandable that the inlet temperature of the temperature-regulating water needs to be lower than the target temperature of the regenerated medium, and its heat exchange takes place in a separate plate heat exchanger to avoid direct mixing with the circulating heat exchange medium and causing contamination. In some embodiments, the median of the regenerated medium temperature range is used as the target setpoint for temperature control. The control system stabilizes the outlet temperature of the regenerated heat exchange medium near the setpoint by adjusting the opening of the temperature-regulating water regulating valve. Optionally, the circulating pump is equipped with a frequency converter, which can adjust the pump speed according to the total system flow demand, thereby achieving energy-saving operation.

[0043] In one embodiment of the present invention, the method includes pretreatment of high-temperature pyrolysis gas and high-temperature flue gas. The pretreatment process includes the following: Before the pyrolysis gas enters the pyrolysis gas heat exchange channel, the high-temperature pyrolysis gas is first subjected to cyclone separation to remove most of the solid particles, and then subjected to deep filtration treatment, such as using a ceramic filter or metal filter element, to further remove tar droplets and fine solid ash particles entrained in the pyrolysis gas. Before the flue gas enters the flue gas heat exchange channel, the high-temperature flue gas is first subjected to spray cooling treatment to reduce the flue gas temperature to the allowable inlet temperature range of the heat exchange equipment, and then subjected to electrostatic dust removal treatment to remove dust particles in the flue gas. The system monitors the temperature and cleanliness indicators of the pretreated pyrolysis gas and flue gas in real time. When the temperature or cleanliness indicator exceeds the allowable range, an alarm is triggered and the operating parameters of the pretreatment process are adjusted. The real-time monitoring process specifically involves installing a resistance thermometer and an online turbidity analyzer on the pipeline after pyrolysis gas pretreatment to continuously measure the temperature and turbidity values ​​of the pretreated pyrolysis gas, respectively. Infrared thermometers and laser dust concentration monitors are installed on the pipeline after flue gas pretreatment to continuously measure the temperature and dust concentration of the pretreated flue gas, respectively. The measured temperatures, turbidity values ​​of the pretreated pyrolysis gas, and the temperatures and dust concentrations of the pretreated flue gas are transmitted to a central controller. The central controller has preset threshold values ​​for pyrolysis gas temperature, turbidity, flue gas temperature, and flue gas dust concentration. The central controller compares the received measurements with the corresponding preset thresholds in real time. When any measured value continuously exceeds its corresponding preset threshold for a preset duration, the controller determines that the indicator exceeds the allowable range, triggers an audible and visual alarm signal, and can also adjust the operating parameters of the pretreatment process, such as the spray water volume and the electrostatic precipitator voltage.

[0044] In specific implementation, the pretreatment and monitoring process for high-temperature pyrolysis gas and high-temperature flue gas is as follows: Before the pyrolysis gas enters the pyrolysis gas heat exchange channel, it undergoes cyclone separation. The high-temperature pyrolysis gas enters the cyclone separator tangentially at a flow rate of 15 meters per second, where centrifugal force removes most of the solid particles larger than 50 micrometers. Deep filtration is then performed using a filter equipped with a sintered metal filter element, with a filtration accuracy of 5 micrometers, further removing tar droplets and fine solid ash particles entrained in the pyrolysis gas. Before the flue gas enters the flue gas heat exchange channel, the high-temperature flue gas undergoes spray cooling treatment. In the spray tower, ambient temperature demineralized water is atomized and sprayed into the high-temperature flue gas through dual-fluid nozzles, reducing the flue gas temperature from 650 degrees Celsius to below the allowable inlet temperature range of 550 degrees Celsius for the heat exchange equipment. Subsequently, electrostatic dust removal is performed. The cooled flue gas enters a high-voltage electrostatic precipitator, where dust particles carried in the flue gas are removed under the action of a high-voltage electric field.

[0045] In some embodiments, the temperature and cleanliness of the pretreated pyrolysis gas and flue gas are monitored in real time. Specifically, a resistance thermometer (RTD) and an online turbidity analyzer are installed on the pipeline after pyrolysis gas pretreatment. The RTD uses a platinum resistance thermometer (Pt100) to continuously measure the temperature of the pretreated pyrolysis gas, and the online turbidity analyzer uses the principle of light scattering to continuously measure the turbidity of the pretreated pyrolysis gas. An infrared thermometer and a laser dust concentration monitor are installed on the pipeline after flue gas pretreatment. The infrared thermometer uses a colorimetric temperature measurement principle to continuously measure the temperature of the pretreated flue gas, and the laser dust concentration monitor uses the backscattering principle to continuously measure the dust concentration of the pretreated flue gas. The measured temperature and turbidity values ​​of the pretreated pyrolysis gas, the temperature of the pretreated flue gas, and the dust concentration values ​​are transmitted to the central controller via 4-20 mA analog signals.

[0046] It is understood that the central controller has preset threshold values ​​for pyrolysis gas temperature, pyrolysis gas turbidity, flue gas temperature, and flue gas dust concentration. For example, the upper limit threshold for pyrolysis gas temperature is set to 450 degrees Celsius, the upper limit threshold for pyrolysis gas turbidity is set to 20 NTU, the upper limit threshold for flue gas temperature is set to 550 degrees Celsius, and the upper limit threshold for flue gas dust concentration is set to 50 mg / m³. The central controller compares the received measured values ​​with the corresponding preset thresholds in real time. When any measured value continuously exceeds its corresponding preset threshold for a preset time, the central controller determines that the indicator exceeds the allowable range and triggers an alarm signal. The logic for alarm triggering can be expressed as follows:

[0047] in: This indicates the status of the alarm signal (1 for triggered, 0 for not triggered). This represents the temperature of the pretreated pyrolysis gas measured in real time. This represents the preset upper limit threshold for the pyrolysis gas temperature. This represents the turbidity value of the pretreated pyrolysis gas measured in real time. This represents the preset upper limit threshold for turbidity of the pyrolysis gas. This represents the pre-treated flue gas temperature value measured in real time. This represents the preset upper limit threshold for flue gas temperature. This represents the real-time measured dust concentration value in the pretreated flue gas. This represents the preset upper limit threshold for flue gas dust concentration. , , , These represent the duration for which each measured value exceeds its corresponding threshold. This represents the preset duration, for example, set to 30 seconds.

[0048] In practical implementation, when the measured temperature of the pyrolysis gas reaches 470 degrees Celsius and remains above 30 seconds, the central controller determines that the pyrolysis gas temperature exceeds the allowable range and triggers an alarm signal. Simultaneously with the alarm triggering, the central controller can adjust the operating parameters of the pretreatment process. For example, it can increase the flow rate of cooling water in the spray cooling system to reduce the flue gas temperature, or adjust the operating voltage of the electrostatic precipitator to improve dust removal efficiency. Optionally, after the alarm is triggered, the central controller displays the specific parameters and values ​​exceeding the limit on the human-machine interface and activates the audible and visual alarm. In some embodiments, the preset duration parameter can be adjusted according to process stability requirements, setting different duration thresholds to adapt to different operating conditions. It can be understood that real-time monitoring and alarm logic provide status feedback for the stable operation of the pretreatment system. When the temperature or cleanliness index exceeds the allowable range, an alarm is triggered, prompting the operator or automatic control system to adjust the operating parameters of the pretreatment process. For example, in the spray cooling system, the opening of the spray water flow control valve can be automatically adjusted; in the electrostatic precipitator system, the output voltage of the high-voltage power supply can be automatically adjusted.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for recovering and utilizing waste heat from both pyrolysis gas and flue gas of oil sludge, characterized in that, include: Obtain flow rate, temperature, and composition data of the high-temperature pyrolysis gas and high-temperature flue gas generated during the pyrolysis of oil sludge; The flow rate, temperature, and composition data are input into the collaborative heat exchange control algorithm to calculate the dynamic distribution scheme of the medium flow rate in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel. The collaborative heat exchange control algorithm is established based on the temperature response characteristics of the heat exchange medium. According to the aforementioned dynamic distribution scheme for medium flow, the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel are dynamically adjusted so that the heat exchange medium recovers heat in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel respectively, thereby generating a high-temperature heat exchange medium. The high-temperature heat exchange medium is introduced into the heat energy utilization device to drive the heat energy utilization device to perform work or supply heat to the outside. After the low-temperature heat exchange medium is discharged from the heat energy utilization device, the low-temperature heat exchange medium is collected and summarized to form a heat exchange medium reflux. The heat exchange medium reflux is subjected to impurity filtration and physical parameter adjustment to generate a regenerated heat exchange medium; The regenerated heat exchange medium is redistributed to the pyrolysis gas heat exchange channel and the flue gas heat exchange channel to form a closed waste heat recovery cycle.

2. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as described in claim 1, characterized in that, The collaborative heat exchange control algorithm is established based on the temperature response characteristics of the heat exchange medium, and its working principle includes: A dynamic model of heat balance between pyrolysis gas and flue gas is established. The dynamic model of heat balance uses the real-time pyrolysis gas flow rate, pyrolysis gas temperature, flue gas flow rate, flue gas temperature, and the current inlet temperature of the heat exchange medium as input variables. Based on the aforementioned dynamic heat balance model, the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel are calculated under a specified outlet temperature target. A heat exchange medium temperature response correction factor is introduced, which is determined by the specific heat capacity, viscosity, and historical average flow rate of the heat exchange medium in the corresponding heat exchange channel. Using the heat exchange medium temperature response correction factor, the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel are corrected respectively, so as to obtain the target value of the medium flow rate of the pyrolysis gas heat exchange channel and the target value of the medium flow rate of the flue gas heat exchange channel. Based on the current total flow limit of the heat exchange medium system, the target flow values ​​of the medium in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are normalized to generate an executable dynamic allocation scheme for the current flow rate. The executable dynamic allocation scheme includes the specific values ​​of the first flow rate and the second flow rate of the heat exchange medium.

3. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as a dual heat source according to claim 2, characterized in that, The dynamic adjustment of the first flow rate of the heat exchange medium flowing through the pyrolysis gas heat exchange channel and the second flow rate of the heat exchange medium flowing through the flue gas heat exchange channel, so that the heat exchange medium recovers heat in the pyrolysis gas heat exchange channel and the flue gas heat exchange channel respectively, to generate a high-temperature heat exchange medium, includes: A first flow regulating valve is installed on the inlet pipe of the pyrolysis gas heat exchange channel, and a second flow regulating valve is installed on the inlet pipe of the flue gas heat exchange channel. The first and second flow rate settings of the heat exchange medium corresponding to the current moment are extracted from the dynamic distribution scheme of the medium flow rate. The first flow rate set value of the heat exchange medium is sent to the first flow regulating valve to control the opening of the first flow regulating valve so that the actual flow rate through the pyrolysis gas heat exchange channel matches the first flow rate set value of the heat exchange medium. The second flow rate set value of the heat exchange medium is sent to the second flow regulating valve to control the opening of the second flow regulating valve so that the actual flow rate through the flue gas heat exchange channel matches the second flow rate set value of the heat exchange medium. In the pyrolysis gas heat exchange channel, the heat exchange medium with a flow rate of the first flow rate set value of the heat exchange medium is subjected to non-contact countercurrent heat exchange with the high temperature pyrolysis gas, absorbing the sensible heat of the pyrolysis gas and generating the first high temperature heat exchange medium. In the flue gas heat exchange channel, the heat exchange medium with a flow rate of the second flow rate set value of the heat exchange medium is subjected to non-contact countercurrent heat exchange with the high temperature flue gas, absorbing the sensible heat of the flue gas and generating a second high temperature heat exchange medium. The first high-temperature heat exchange medium and the second high-temperature heat exchange medium are combined to generate a combined high-temperature heat exchange medium.

4. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as described in claim 3, characterized in that, Introducing the high-temperature heat exchange medium into the heat energy utilization device to drive the heat energy utilization device to perform work or supply heat to the outside world includes: The combined high-temperature heat exchange medium is introduced into the tube side of the steam generator to heat the water in the shell side of the steam generator and generate saturated steam or superheated steam. The generated steam is introduced into a steam turbine to drive the turbine rotor to rotate. The turbine rotor is connected to a generator to convert rotational mechanical energy into electrical energy output. The exhaust steam discharged from the turbine is introduced into the condenser, where it is condensed into condensate. The condensate is pressurized by the feedwater pump and sent back to the shell side of the steam generator to complete the steam power cycle. After the water is heated to generate steam, the temperature of the heat exchange medium discharged from the tube side of the steam generator decreases, forming the low-temperature heat exchange medium.

5. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as described in claim 1, characterized in that, The heat exchange medium reflux is subjected to impurity filtration and physical parameter adjustment to generate a regenerated heat exchange medium, including: The low-temperature heat exchange medium is fed into a multi-stage filtration device to remove solid particulate impurities and droplet impurities carried therein in sequence. The composition of the filtered low-temperature heat exchange medium was analyzed, and its acidity, alkalinity and conductivity were detected. Based on the detection results of pH and conductivity, chemical agents are added to the filtered low-temperature heat exchange medium to adjust its pH to a preset neutral range and its conductivity to below a preset threshold, thereby generating a chemically stable heat exchange medium. The chemically stable heat exchange medium is pressurized and its temperature is finely adjusted to increase its pressure to the circulating working pressure and stabilize its temperature within the preset regeneration medium temperature range to generate the regenerated heat exchange medium.

6. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as described in claim 5, characterized in that, The pressurization and temperature fine-tuning treatment of the chemically stable heat exchange medium includes: A chemically stable heat exchange medium is introduced into a circulating pump, and the pressure of the heat exchange medium is increased to the circulating working pressure by the circulating pump. The circulating working pressure must meet the requirements of the heat exchange medium overcoming flow resistance and maintaining good heat transfer in the heat exchange channel. Temperature-regulating water is introduced from an external low-temperature heat source or the low-temperature circulating water in the plant area. Before the pressurized heat exchange medium enters the heat exchange channel, the temperature-regulating water and the pressurized heat exchange medium exchange heat in a mixing device. By controlling the flow rate of the temperature-regulating water, the temperature of the mixed heat exchange medium is adjusted so that it falls near the midpoint of the preset regeneration medium temperature range. The heat exchange medium, after temperature fine-tuning, is delivered to the inlet of the heat exchange medium distribution manifold.

7. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as described in claim 1, characterized in that, The method further includes pretreatment of the high-temperature pyrolysis gas and high-temperature flue gas, including: Before the pyrolysis gas enters the pyrolysis gas heat exchange channel, the high-temperature pyrolysis gas is subjected to cyclone separation and deep filtration to remove tar droplets and solid ash particles entrained in the pyrolysis gas. Before the flue gas enters the flue gas heat exchange channel, the high-temperature flue gas is sprayed to cool down and electrostatically removed to reduce the flue gas temperature to the allowable inlet temperature range of the heat exchange equipment and remove dust particles from the flue gas. The temperature and cleanliness of the pretreated pyrolysis gas and flue gas are monitored in real time. When the temperature or cleanliness exceeds the allowable range, an alarm is triggered and the operating parameters of the pretreatment process are adjusted.

8. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as described in claim 7, characterized in that, The real-time monitoring of the temperature and cleanliness indicators of the pretreated pyrolysis gas and flue gas includes: A resistance thermometer and an online turbidity analyzer are installed on the pipeline after the pyrolysis gas pretreatment to continuously measure the temperature and turbidity of the pretreated pyrolysis gas. An infrared thermometer and a laser dust concentration monitor are installed on the pipeline after flue gas pretreatment to continuously measure the temperature and dust concentration of the pretreated flue gas, respectively. The measured temperature, turbidity, temperature, and dust concentration of the pretreated pyrolysis gas are transmitted to the central controller. The central controller is preset with upper limit thresholds for pyrolysis gas temperature, pyrolysis gas turbidity, flue gas temperature, and flue gas dust concentration. The central controller compares the received measurement values ​​with the corresponding preset thresholds in real time. When any measurement value continuously exceeds its corresponding preset threshold for a preset duration, it is determined that the indicator exceeds the allowable range and an alarm signal is triggered.

9. The method for recovering and utilizing waste heat from both sludge pyrolysis gas and flue gas as a dual heat source according to claim 2, characterized in that, Using the heat exchange medium temperature response correction factor, the theoretical flow rates of the heat exchange medium required for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel are corrected respectively to obtain the target flow rates of the medium for the pyrolysis gas heat exchange channel and the flue gas heat exchange channel, including: Obtain the theoretical flow rate of the heat exchange medium required for the pyrolysis gas heat exchange channel and the theoretical flow rate of the heat exchange medium required for the flue gas heat exchange channel, calculated by the aforementioned dynamic heat balance model. Query the specific heat capacity and viscosity parameters of the current heat exchange medium from the preset physical property parameter database; Extract the historical average flow rate of the heat exchange medium in the pyrolysis gas heat exchange channel and the historical average flow rate in the flue gas heat exchange channel within the preset statistical period from the historical operation database. Based on the specific heat capacity, viscosity, and historical average flow rate of the current heat exchange medium in the pyrolysis gas heat exchange channel, the heat exchange medium temperature response correction factor in the pyrolysis gas heat exchange channel is calculated. Based on the specific heat capacity, viscosity, and historical average flow velocity of the current heat exchange medium in the flue gas heat exchange channel, the heat exchange medium temperature response correction factor in the flue gas heat exchange channel is calculated. The target value of the heat exchange medium flow rate in the pyrolysis gas heat exchange channel is calculated by multiplying the heat exchange medium temperature response correction factor in the pyrolysis gas heat exchange channel by the theoretical flow rate of the heat exchange medium required in the pyrolysis gas heat exchange channel. The target value of the medium flow rate in the flue gas heat exchange channel is calculated by multiplying the temperature response correction factor of the heat exchange medium in the flue gas heat exchange channel by the theoretical flow rate of the heat exchange medium required in the flue gas heat exchange channel. The target flow rate of the medium in the pyrolysis gas heat exchange channel and the target flow rate of the medium in the flue gas heat exchange channel are output to the normalization processing step.

10. A dual-heat-source waste heat recovery and utilization system for pyrolysis gas and flue gas from oil sludge, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the waste heat recovery and utilization method of dual heat sources of sludge pyrolysis gas and flue gas as described in any one of claims 1 to 9.

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