Intelligent control system for thermal balance and hydrophobic recovery in urea hydrolysis ammonia production system

Abstract

This invention discloses an intelligent control system for thermal balance and condensate recovery in a urea hydrolysis ammonia production system. The system includes a thermal parameter monitoring module, a condensate state sensing module, a thermal balance calculation module, a condensate recovery optimization module, a steam regulating valve execution unit, a condensate regulating valve execution unit, and an intelligent collaborative controller. By constructing an integrated intelligent control system, this invention decouples and collaboratively optimizes the thermal balance control of the hydrolyzer and the operating status of the condensate recovery device. It can sense changes in internal thermal parameters in real time and predict heat load demand based on a dynamic energy balance model, thereby proactively adjusting the steam supply. Through refined control of the condensate recovery end, this invention ensures that the condensate valve opens under optimal pressure differential and liquid level conditions, significantly improving the recovery rate of high-temperature condensate and reducing heat loss and working fluid consumption.

Description

Technical Field

[0001] This invention relates to the field of flue gas denitrification technology in coal-fired power plants, specifically to an intelligent control system for thermal balance and hydrophobic recovery in urea hydrolysis ammonia production systems. Background Technology

[0002] Urea hydrolysis for ammonia production has become the mainstream technology for preparing reducing agents for flue gas denitrification in coal-fired power plants due to the significantly higher safety of urea storage and transportation compared to liquid ammonia. The core of this technology is the use of high-temperature saturated steam as a heat source to heat and decompose urea solution within a hydrolysis reactor, generating ammonia-rich products for denitrification. In actual operation, the system requires extremely high stability of the heat source; maintaining thermal balance directly affects the urea hydrolysis efficiency, ammonia production rate, and the long-term safe and stable operation of the system.

[0003] Currently, conventional urea hydrolysis ammonia production systems mostly use simple PID control loops to independently control steam regulating valves and condensate drain valves, which are insufficient to cope with complex operating conditions such as rapid changes in unit load and fluctuations in steam pressure. When thermal parameters are unbalanced, it often leads to temperature fluctuations in the hydrolyzer, affecting ammonia production. At the same time, due to lag or improper adjustment of the condensate recovery system, high-temperature condensate often cannot be effectively recovered or is discharged with steam, which not only wastes a large amount of high-quality thermal energy and increases the power plant's makeup water rate and energy consumption, but may also cause safety hazards such as water hammer. Summary of the Invention

[0004] To address this issue, the present invention provides an intelligent control system for thermal balance and hydrophobic recovery in a urea hydrolysis ammonia production system. This system solves the problem in the prior art where imbalances in thermal parameters often lead to temperature fluctuations in the hydrolyzer, affecting ammonia production. Furthermore, the hydrophobic recovery system, due to delayed or improper adjustment, often results in the ineffective recovery of high-temperature condensate or its emission with steam, which not only wastes a large amount of high-quality thermal energy and increases the power plant's water replenishment rate and energy consumption, but may also cause safety hazards such as water hammer.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system includes:

[0007] The thermal parameter monitoring module is used to collect the operating parameters of the hydrolyzer's thermal side in real time. The operating parameters include at least the steam inlet pressure, steam inlet temperature, internal reaction temperature of the hydrolyzer, and condensate temperature at the outlet of the drain manifold.

[0008] The hydrophobic state sensing module is used to monitor the working status parameters of the hydrophobic recovery pipeline in real time. The working status parameters include at least the pressure difference before and after the hydrophobic valve, the opening degree of the hydrophobic valve, and the liquid level height of the hydrophobic recovery tank.

[0009] The thermal balance calculation module is electrically connected to the thermal parameter monitoring module and the hydrophobic state sensing module, respectively. The thermal balance calculation module has a built-in dynamic energy balance model based on the first law of thermodynamics. It is used to calculate the theoretical heat load required by the hydrolyzer in real time according to the received operating parameters and working status parameters, and generate thermal balance control commands based on the deviation between the theoretical heat load and the actual supplied heat load.

[0010] The hydrophobic recovery optimization module is electrically connected to the hydrophobic state sensing module. The hydrophobic recovery optimization module has a built-in collaborative control model based on pressure difference and liquid level dual parameters. It is used to dynamically generate recovery control commands to adjust the opening of the hydrophobic valve according to the received pressure difference before and after the hydrophobic valve and the liquid level height of the hydrophobic recovery tank, so as to maintain the high-efficiency discharge state of the hydrophobic valve near the critical point of gas-liquid two-phase flow.

[0011] The steam regulating valve actuator is electrically connected to the thermal balance calculation module and is used to receive the thermal balance control command and adjust the valve opening of the steam inlet pipeline to accurately control the steam flow rate entering the hydrolyzer.

[0012] A condensate drain control valve actuator, electrically connected to the condensate recovery optimization module, is used to receive the recovery control command and adjust the valve opening on the condensate drain pipeline to control the discharge and recovery rate of high-temperature condensate; and

[0013] The intelligent collaborative controller is communicatively connected to the thermal balance calculation module and the hydrophobic recovery optimization module, respectively. The intelligent collaborative controller is used to perform cross-verification and priority arbitration on the thermal balance control command and the recovery control command, and to send forced safety protection commands to the steam regulating valve execution unit and / or the hydrophobic regulating valve execution unit during system startup, shutdown or fault conditions.

[0014] Preferably, the thermal balance calculation module includes a dynamic energy balance calculation unit. The dynamic energy balance calculation unit calculates the steam mass flow correction value required to maintain the thermal balance of the hydrolyzer based on the difference between the target value and the measured value of the reaction temperature inside the hydrolyzer, combined with the saturated steam enthalpy value of the current steam inlet pressure. The correction value is then superimposed on the feedforward control quantity to generate the thermal balance control command.

[0015] Preferably, the condensate recovery optimization module includes a critical pressure difference identification unit. The critical pressure difference identification unit compares the real-time collected pressure difference data before and after the condensate valve with the built-in condensate valve characteristic curve library to determine whether the current condensate valve is in an abnormal operating range of steam leakage or water accumulation blockage. When it is determined to be in an abnormal operating range, the condensate recovery optimization module combines the current liquid level change rate of the condensate recovery tank to generate the recovery control command for finely adjusting the opening of the condensate valve, so as to drive the condensate valve back to the critical operating point of only discharging condensate and preventing steam from escaping.

[0016] Preferably, the system further includes a hydrophobic quality analysis module electrically connected to the hydrophobic state sensing module. The hydrophobic quality analysis module has a built-in conductivity sensor or temperature gradient sensor for real-time detection of the purity or subcooling of the condensate in the hydrophobic recovery pipeline. When the hydrophobic recovery optimization module generates a recovery control command, it also receives the quality signal output by the hydrophobic quality analysis module. When the condensate quality is detected to be lower than the preset reuse standard, the hydrophobic recovery optimization module prioritizes controlling the hydrophobic regulating valve actuator to discharge the inferior condensate into the sewage pipeline, rather than recycling it to the hydrophobic recovery tank.

[0017] Preferably, the intelligent collaborative controller integrates a working condition identification and decoupling matrix. This decoupling matrix is ​​used to analyze the disturbance impact of thermal balance control actions on the hydrophobic recovery state, and the disturbance impact of hydrophobic recovery control actions on the upstream thermal balance. Based on the analysis results, the intelligent collaborative controller applies a decoupling compensation coefficient to the thermal balance control command and the recovery control command. The calculation formula for the decoupling compensation coefficient is as follows:

[0018] ,

[0019] Where e(t) is the deviation between the current thermodynamic parameter or hydrophobic state parameter and its set target value, and Kp, Ki, and Kd are adaptive parameters dynamically tuned by the fuzzy rule base according to the real-time operating conditions. By applying this decoupling compensation coefficient, the thermodynamic and hydrophobic side controls can be mutually fed forward and dynamically coordinated, suppressing the control coupling oscillation caused by the parameter fluctuation on the other side due to the adjustment action on one side.

[0020] Preferably, the intelligent collaborative controller further includes a data interaction interface for communicating with the power plant's distributed control system, used to receive unit load command signals; the thermal balance calculation module calculates the preheating load demand in advance based on the received unit load command signals and a preset load-steam consumption function relationship, and generates a feedforward control signal superimposed on the thermal balance control command to adjust the steam regulating valve execution unit in advance to compensate for the thermal system inertial delay caused by changes in unit load.

[0021] Preferably, the thermal balance calculation module further includes a historical data storage unit and a model self-calibration unit; the model self-calibration unit periodically calls the operating data stored in the historical data storage unit to perform rolling optimization and correction on the heat transfer coefficient and heat loss coefficient in the dynamic energy balance model, so that the calculated value of the theoretical heat load approximates the actual heat demand of the system under different operating cycles and different ambient temperatures.

[0022] Preferably, the hydrophobic recovery optimization module further includes a life prediction unit. The life prediction unit calculates the frequency and magnitude of the deviation of the hydrophobic valve from the critical operating point based on the historical data recorded by the critical differential pressure identification unit, and generates a health status assessment report and maintenance early warning information for the hydrophobic valve in combination with the number of valve actions, and sends it to the monitoring center through the intelligent collaborative controller.

[0023] The present invention has the following advantages: By constructing an integrated intelligent control system, the present invention decouples and coordinates the thermal balance control of the hydrolyzer with the operating status of the hydrophobic recovery device, which can sense the changes in the internal thermal parameters of the system in real time and predict the heat load demand based on the dynamic energy balance model, thereby adjusting the steam supply in advance.

[0024] This invention ensures that the condensate drain valve opens under optimal pressure differential and liquid level conditions through precise control of the condensate recovery end, significantly improving the recovery rate of high-temperature condensate and reducing heat loss and working fluid consumption.

[0025] This invention can automatically correct the control logic based on historical operating data, adapt to the variable operating conditions of the unit under different loads, effectively improve the overall energy efficiency, operational stability and automation of the urea hydrolysis ammonia production system, and reduce the workload of on-site maintenance personnel. Attached Figure Description

[0026] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0027] Figure 1 A block diagram of the intelligent control system for thermal balance and hydrophobic recovery of the urea hydrolysis ammonia production system provided in the embodiments of this application. Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these embodiments are merely for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Technical engineers in the field can make some non-essential improvements and adjustments to the present invention based on the above-described content. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1 The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system includes:

[0030] The thermal parameter monitoring module is used to collect the operating parameters of the hydrolyzer's thermal side in real time. The operating parameters include at least the steam inlet pressure, steam inlet temperature, internal reaction temperature of the hydrolyzer, and condensate temperature at the outlet of the drain manifold.

[0031] The hydrophobic state sensing module is used to monitor the working status parameters of the hydrophobic recovery pipeline in real time. The working status parameters include at least the pressure difference before and after the hydrophobic valve, the opening degree of the hydrophobic valve, and the liquid level height of the hydrophobic recovery tank.

[0032] The thermal balance calculation module is electrically connected to the thermal parameter monitoring module and the hydrophobic state sensing module, respectively. The thermal balance calculation module has a built-in dynamic energy balance model based on the first law of thermodynamics. It is used to calculate the theoretical heat load required by the hydrolyzer in real time according to the received operating parameters and working status parameters, and generate thermal balance control commands based on the deviation between the theoretical heat load and the actual supplied heat load.

[0033] The hydrophobic recovery optimization module is electrically connected to the hydrophobic state sensing module. The hydrophobic recovery optimization module has a built-in collaborative control model based on pressure difference and liquid level dual parameters. It is used to dynamically generate recovery control commands to adjust the opening of the hydrophobic valve according to the received pressure difference before and after the hydrophobic valve and the liquid level height of the hydrophobic recovery tank, so as to maintain the high-efficiency discharge state of the hydrophobic valve near the critical point of gas-liquid two-phase flow.

[0034] The steam regulating valve actuator is electrically connected to the thermal balance calculation module and is used to receive the thermal balance control command and adjust the valve opening of the steam inlet pipeline to accurately control the steam flow rate entering the hydrolyzer.

[0035] A condensate drain control valve actuator, electrically connected to the condensate recovery optimization module, is used to receive the recovery control command and adjust the valve opening on the condensate drain pipeline to control the discharge and recovery rate of high-temperature condensate; and

[0036] The intelligent collaborative controller is communicatively connected to the thermal balance calculation module and the hydrophobic recovery optimization module, respectively. The intelligent collaborative controller is used to perform cross-verification and priority arbitration on the thermal balance control command and the recovery control command, and to send forced safety protection commands to the steam regulating valve execution unit and / or the hydrophobic regulating valve execution unit during system startup, shutdown or fault conditions.

[0037] The thermal balance calculation module includes a dynamic energy balance calculation unit. The dynamic energy balance calculation unit calculates the steam mass flow correction value required to maintain the thermal balance of the hydrolyzer based on the difference between the target value and the measured value of the reaction temperature inside the hydrolyzer, combined with the saturated steam enthalpy value of the current steam inlet pressure. The correction value is then superimposed on the feedforward control quantity to generate the thermal balance control command.

[0038] The condensate recovery optimization module includes a critical pressure difference identification unit. This unit compares the real-time collected pressure difference data before and after the condensate valve with a built-in condensate valve characteristic curve library to determine whether the condensate valve is currently in an abnormal operating range due to steam leakage or water accumulation blockage. When it is determined to be in an abnormal operating range, the condensate recovery optimization module, in conjunction with the current liquid level change rate of the condensate recovery tank, generates a recovery control command to finely adjust the condensate valve opening, thereby driving the condensate valve back to the critical operating point where only condensate is discharged and steam escape is prevented.

[0039] It also includes a hydrophobic quality analysis module electrically connected to the hydrophobic state sensing module. The hydrophobic quality analysis module has a built-in conductivity sensor or temperature gradient sensor for real-time detection of the purity or subcooling of condensate in the hydrophobic recovery pipeline. When the hydrophobic recovery optimization module generates a recovery control command, it also receives the quality signal output by the hydrophobic quality analysis module. When the condensate quality is detected to be lower than the preset reuse standard, the hydrophobic recovery optimization module prioritizes controlling the hydrophobic regulating valve actuator to discharge the inferior condensate to the sewage pipeline instead of recycling it to the hydrophobic recovery tank.

[0040] The intelligent collaborative controller integrates a working condition identification and decoupling matrix. This decoupling matrix analyzes the disturbance impact of thermal balance control actions on the hydrophobic recovery state, and the disturbance impact of hydrophobic recovery control actions on the upstream thermal balance. Based on the analysis results, the intelligent collaborative controller applies a decoupling compensation coefficient to the thermal balance control command and the recovery control command. The formula for calculating the decoupling compensation coefficient is as follows:

[0041] ,

[0042] Where e(t) is the deviation between the current thermodynamic parameter or hydrophobic state parameter and its set target value, and Kp, Ki, and Kd are adaptive parameters dynamically tuned by the fuzzy rule base according to the real-time operating conditions. By applying this decoupling compensation coefficient, the thermodynamic and hydrophobic side controls can be mutually fed forward and dynamically coordinated, suppressing the control coupling oscillation caused by the parameter fluctuation on the other side due to the adjustment action on one side.

[0043] As an embodiment of the above solution, it has:

[0044] Urea hydrolysis ammonia production system in the SCR denitrification unit of a 2×600MW coal-fired power plant.

[0045] I. System Hardware Composition

[0046] A smart electric regulating valve is installed on the steam inlet pipeline (DN150, design pressure 1.0MPa) as the steam regulating valve actuator. A Rosemount 3051 pressure transmitter is installed upstream of the valve to collect the steam inlet pressure, and a PT100 RTD is installed downstream to collect the steam inlet temperature. Two multi-point flexible armored thermocouples are installed inside the hydrolysis reactor body for accurate measurement of the internal reaction temperature. On the condensate recovery pipeline, the condensate valve is a pneumatic diaphragm regulating valve, with differential pressure transmitters installed upstream and downstream to monitor the pressure difference across the condensate valve in real time. The condensate recovery tank is a vertical cylindrical tank equipped with a radar level gauge to monitor the liquid level. A conductivity sensor and a dual platinum resistance temperature gradient sensor are also added to the pipeline section before the condensate recovery tank inlet, forming a condensate quality analysis module to detect the purity and subcooling of the condensate.

[0047] II. Thermal Balance Calculation and Control Logic

[0048] The thermal balance calculation module is integrated into the PLC controller. The built-in dynamic energy balance model is based on the following heat balance equation: Q_steam × η = Q_reaction + Q_loss. Where Q_steam is the heat carried in by the steam, calculated from the saturated steam enthalpy table based on the steam inlet pressure (measured by a pressure transmitter); η is the heat exchange efficiency; Q_reaction is the heat absorbed by the urea hydrolysis reaction, which is related to the reaction temperature inside the hydrolyzer and the urea feed rate; and Q_loss is the heat loss from the equipment.

[0049] During operation, when the unit load rapidly decreases from 600MW to 450MW, the amount of ammonia required for denitrification decreases. The thermal balance calculation module, based on the difference (-5℃) between the measured internal reaction temperature (135℃) and the target temperature (140℃) of the hydrolyzer, and combined with the saturated steam enthalpy (2778kJ / kg) at the current steam pressure (0.8MPa), calculates that the reduced steam mass flow rate required to maintain thermal balance is 85kg / h. This correction value is superimposed on the feedforward control quantity (derived from the load-steam consumption function, where a 10% decrease in load corresponds to a 7% reduction in preheating load demand), generating a thermal balance control command (closing the valve from 42% to 36%), which is then executed by the steam regulating valve actuator.

[0050] III. Optimization and Quality Assessment of Hydrophobic Recycling

[0051] The condensate recovery optimization module receives real-time data from the differential pressure transmitter. The current pressure difference across the condensate drain valve is 0.25 MPa. The built-in critical differential pressure identification unit compares this data with the condensate drain valve characteristic curve library (the valve operates optimally within the 0.20-0.28 MPa differential pressure range) and determines that it is within the normal operating range. Simultaneously, the condensate recovery tank level is 1.8 m (set upper limit 2.5 m, lower limit 0.8 m), with a level change rate of +0.1 m / h, which is within the normal fluctuation range.

[0052] When the system had been running for three hours, the conductivity sensor in the hydrophobicity quality analysis module detected a sudden increase in the conductivity of the condensate from the normal 5 μS / cm to 25 μS / cm, exceeding the preset reuse standard (10 μS / cm). At this point, the hydrophobicity recovery optimization module responded immediately. The generated recovery control command no longer directed the condensate to the recovery tank, but instead controlled the hydrophobicity regulating valve actuator to switch to the drain pipe, discharging the substandard condensate. After 15 minutes, the conductivity returned to normal, and the command automatically switched back to recovery mode.

[0053] IV. Decoupled Computation and Coordination of Intelligent Cooperative Controllers

[0054] The intelligent collaborative controller integrates operating condition identification and decoupling matrices. During one control operation, the thermal balance calculation module issues a command to increase the steam regulating valve opening by 5% (from 35% to 40%) to cope with the increased ammonia demand. This action is expected to lead to an increase in the flow rate on the condensate side, which may cause the pressure difference across the condensate valve to rise from 0.22 MPa to 0.30 MPa in a short period of time, exceeding the upper limit of the optimal operating range.

[0055] The intelligent collaborative controller analyzes the decoupling matrix to determine the impact of the disturbance and immediately applies a decoupling compensation coefficient to the upcoming recycling control command generated by the hydrophobic recycling optimization module. The decoupling compensation coefficient is calculated using an incremental PID algorithm. .

[0056] Under this operating condition, e(t) represents the deviation between the current pressure difference across the steam trap (0.22 MPa) and the target pressure difference (0.24 MPa). The fuzzy rule base dynamically adjusts Kp=1.2, Ki=0.15, and Kd=0.3 based on the current load change rate (+5% / min). The calculated compensation is D(t)=+3.2%, meaning the steam trap needs to be pre-opened by 3.2% to accommodate the upcoming flow increase and prevent steam leakage caused by a sudden increase in pressure difference. Through this dynamic, feedforward coordination, fluctuations in steam trap parameters caused by thermal-side regulation are effectively suppressed, achieving smooth decoupling and coordinated operation of the two loops.

[0057] In this embodiment, through the coordinated work and intelligent control of the above modules, the thermal efficiency of the urea hydrolysis ammonia production system is improved by about 8%, and the hydrophobic recovery rate reaches more than 98%, which is significantly better than the conventional independent control method.

[0058] The intelligent collaborative controller also includes a data interaction interface for communicating with the power plant's distributed control system to receive unit load command signals. The thermal balance calculation module calculates the preheating load demand in advance based on the received unit load command signals and the preset load-steam consumption function relationship, and generates a feedforward control signal that is superimposed on the thermal balance control command to adjust the steam regulating valve actuator in advance and compensate for the thermal system inertial delay caused by changes in unit load.

[0059] In actual power plant operation, unit load changes are the main source of disturbances causing steam parameter fluctuations, and these disturbances have a significant inertial delay. By receiving load commands, the thermal balance calculation module can predict future heat load demands (for example, when the unit prepares to increase load, the ammonia demand will increase synchronously), and generate feedforward control signals in advance based on the preset load-steam consumption function relationship. These signals are then superimposed on the thermal balance control commands, thereby proactively adjusting the steam regulating valves. Before the disturbance actually affects the reaction temperature inside the hydrolyzer, the steam supply is increased or decreased, effectively compensating for system inertia, greatly suppressing temperature fluctuations, ensuring a precise match between the ammonia production rate and the unit's denitrification requirements, and improving the system's adaptability to grid load changes.

[0060] The thermal balance calculation module also includes a historical data storage unit and a model self-calibration unit. The model self-calibration unit periodically calls upon the operational data stored in the historical data storage unit to perform rolling optimization and correction on the heat transfer coefficient and heat loss coefficient in the dynamic energy balance model, ensuring that the calculated theoretical heat load value closely approximates the actual heat demand of the system under different operating cycles and ambient temperatures. During long-term operation, the heat exchange surfaces of the urea hydrolysis ammonia production system may experience a decrease in heat transfer coefficient due to scaling, and seasonal changes in ambient temperature will also affect the heat dissipation loss coefficient of the equipment. If the dynamic energy balance model uses fixed parameters, the theoretical calculation will gradually deviate from reality, leading to a decrease in control accuracy. By setting up the model self-calibration unit, the system can periodically call upon the operational data accumulated in the historical data storage unit (covering different operating conditions and seasons) and use algorithms such as recursive least squares or neural networks to perform rolling optimization and correction on the heat transfer coefficient and heat loss coefficient in the model.

[0061] The hydrophobic recovery optimization module also includes a life prediction unit. Based on the historical data recorded by the critical differential pressure identification unit, the life prediction unit counts the frequency and magnitude of the hydrophobic valve deviating from the critical operating point, and combines this with the number of valve actions to generate a health status assessment report and maintenance early warning information for the hydrophobic valve. This information is then sent to the monitoring center via the intelligent collaborative controller. By deeply mining the historical data recorded by the critical differential pressure identification unit, the module counts the frequency and magnitude of the hydrophobic valve deviating from the optimal critical operating point, as well as the cumulative number of valve actions. Combined with the valve's stress-life (SN) curve or degradation model, the module quantitatively assesses the health status of the hydrophobic valve.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A smart control system for thermal balance and hydrophobic recovery in a urea hydrolysis ammonia production system, characterized in that, include: The thermal parameter monitoring module is used to collect the operating parameters of the hydrolyzer's thermal side in real time. The operating parameters include at least the steam inlet pressure, steam inlet temperature, internal reaction temperature of the hydrolyzer, and condensate temperature at the outlet of the drain manifold. The hydrophobic state sensing module is used to monitor the working status parameters of the hydrophobic recovery pipeline in real time. The working status parameters include at least the pressure difference before and after the hydrophobic valve, the opening degree of the hydrophobic valve, and the liquid level height of the hydrophobic recovery tank. The thermal balance calculation module is electrically connected to the thermal parameter monitoring module and the hydrophobic state sensing module, respectively. The thermal balance calculation module has a built-in dynamic energy balance model based on the first law of thermodynamics. It is used to calculate the theoretical heat load required by the hydrolyzer in real time according to the received operating parameters and working status parameters, and generate thermal balance control commands based on the deviation between the theoretical heat load and the actual supplied heat load. The hydrophobic recovery optimization module is electrically connected to the hydrophobic state sensing module. The hydrophobic recovery optimization module has a built-in collaborative control model based on pressure difference and liquid level dual parameters. It is used to dynamically generate recovery control commands to adjust the opening of the hydrophobic valve according to the received pressure difference before and after the hydrophobic valve and the liquid level height of the hydrophobic recovery tank, so as to maintain the high-efficiency discharge state of the hydrophobic valve near the critical point of gas-liquid two-phase flow. The steam regulating valve actuator is electrically connected to the thermal balance calculation module and is used to receive the thermal balance control command and adjust the valve opening of the steam inlet pipeline to control the steam flow rate entering the hydrolyzer. The condensate regulating valve actuator is electrically connected to the condensate recovery optimization module and is used to receive the recovery control command and adjust the valve opening on the condensate pipeline to control the discharge and recovery rate of high-temperature condensate. as well as The intelligent collaborative controller is communicatively connected to the thermal balance calculation module and the hydrophobic recovery optimization module, respectively. The intelligent collaborative controller is used to perform cross-verification and priority arbitration on the thermal balance control command and the recovery control command, and to send forced safety protection commands to the steam regulating valve execution unit and / or the hydrophobic regulating valve execution unit during system startup, shutdown or fault conditions.

2. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 1, characterized in that, The thermal balance calculation module includes a dynamic energy balance calculation unit. The dynamic energy balance calculation unit calculates the steam mass flow correction value required to maintain the thermal balance of the hydrolyzer based on the difference between the target value and the measured value of the reaction temperature inside the hydrolyzer, combined with the saturated steam enthalpy value of the current steam inlet pressure. The correction value is then superimposed on the feedforward control quantity to generate the thermal balance control command.

3. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 2, characterized in that, The condensate recovery optimization module includes a critical pressure difference identification unit. This unit compares the real-time collected pressure difference data before and after the condensate valve with a built-in condensate valve characteristic curve library to determine whether the condensate valve is currently in an abnormal operating range due to steam leakage or water accumulation blockage. When it is determined to be in an abnormal operating range, the condensate recovery optimization module, in conjunction with the current liquid level change rate of the condensate recovery tank, generates a recovery control command to adjust the condensate valve opening, thereby driving the condensate valve back to the critical operating point where only condensate is discharged and steam escape is prevented.

4. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 3, characterized in that, It also includes a hydrophobic quality analysis module electrically connected to the hydrophobic state sensing module. The hydrophobic quality analysis module has a built-in conductivity sensor or temperature gradient sensor for real-time detection of the purity or subcooling of condensate in the hydrophobic recovery pipeline. When the hydrophobic recovery optimization module generates a recovery control command, it also receives the quality signal output by the hydrophobic quality analysis module. When the condensate quality is detected to be lower than the preset reuse standard, the hydrophobic recovery optimization module prioritizes controlling the hydrophobic regulating valve actuator to discharge the inferior condensate into the sewage pipeline.

5. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 4, characterized in that, The intelligent collaborative controller integrates a working condition identification and decoupling matrix. This decoupling matrix analyzes the disturbance impact of thermal balance control actions on the hydrophobic recovery state, and the disturbance impact of hydrophobic recovery control actions on the upstream thermal balance. Based on the analysis results, the intelligent collaborative controller applies a decoupling compensation coefficient to the thermal balance control command and the recovery control command. The formula for calculating the decoupling compensation coefficient is as follows: ， Where e(t) is the deviation between the current thermodynamic parameter or hydrophobic state parameter and its set target value, and Kp, Ki, and Kd are adaptive parameters dynamically tuned by the fuzzy rule base according to the real-time operating conditions. By applying this decoupling compensation coefficient, the thermodynamic and hydrophobic side controls can be mutually fed forward and dynamically coordinated, suppressing the control coupling oscillation caused by the parameter fluctuation on the other side due to the adjustment action on one side.

6. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 1, characterized in that, The intelligent collaborative controller also includes a data interaction interface for communicating with the power plant's distributed control system to receive unit load command signals. The thermal balance calculation module calculates the preheating load demand in advance based on the received unit load command signals and the preset load-steam consumption function relationship, and generates a feedforward control signal that is superimposed on the thermal balance control command to adjust the steam regulating valve actuator in advance and compensate for the thermal system inertial delay caused by changes in unit load.

7. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 2, characterized in that, The thermal balance calculation module also includes a historical data storage unit and a model self-calibration unit. The model self-calibration unit periodically calls the operating data stored in the historical data storage unit to perform rolling optimization and correction on the heat transfer coefficient and heat loss coefficient in the dynamic energy balance model, so that the calculated value of the theoretical heat load approximates the actual heat demand of the system under different operating cycles and different ambient temperatures.

8. The intelligent control system for thermal balance and hydrophobic recovery in the urea hydrolysis ammonia production system according to claim 3, characterized in that, The hydrophobic recovery optimization module also includes a life prediction unit. The life prediction unit calculates the frequency and magnitude of the deviation of the hydrophobic valve from the critical operating point based on the historical data recorded by the critical differential pressure identification unit, and generates a health status assessment report and maintenance early warning information for the hydrophobic valve by combining the number of valve actions, and sends it to the monitoring center through the intelligent collaborative controller.

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