Closed loop cooling water purification and thermal energy cascade utilization system

Abstract

This invention relates to the field of industrial water treatment and waste heat recovery, and discloses a closed-loop cooling water purification and cascaded thermal energy utilization system. The system includes an energy cascaded coupling utilization module for graded recovery of the thermal energy of high-temperature cooling water into electrical energy, cooling energy, and thermal energy; a high-temperature current-varying capacitor deionization dynamic matrix purification module for purifying the cooling water; a sensing and collaborative control module for monitoring energy output and purification unit status, and determining when to perform regeneration; and a low-temperature membrane distillation zero-discharge module. The sensing and collaborative control module initiates regeneration of the purification module only when energy is abundant, based on a regeneration decision algorithm. The low-temperature membrane distillation zero-discharge module utilizes the waste water thermal energy at the end of the energy cascade module to treat the high-concentration concentrate discharged from the purification module, recovering pure water and achieving zero discharge. Through the synergistic effect of each module, this system achieves efficient cascaded energy utilization, intelligent operation, and a closed-loop water resource system.

Description

Technical Field

[0001] This invention relates to the field of industrial water treatment and waste heat recovery technology, specifically a closed-loop cooling water purification and thermal energy cascade utilization system. Background Technology

[0002] Graphitization furnaces are core thermal equipment used in the production of special graphite materials, lithium battery anode materials, and other key products. Their operation involves heat treatment of carbonaceous materials at ultra-high temperatures. During high-temperature industrial processes such as graphitization furnace operation, large quantities of high-temperature cooling water are generated. Existing cooling water systems typically focus on circulation and cooling, failing to effectively recover the significant heat energy contained within, or only utilizing it inefficiently in a single way, resulting in energy waste. Furthermore, the electrical energy required for the operation of auxiliary equipment such as purification units and pumps in these systems is usually drawn from the external power grid, increasing overall operating costs and energy consumption.

[0003] To achieve the recycling of cooling water, water purification is necessary to prevent scaling and corrosion of equipment. Existing technologies employing purification techniques such as capacitor deionization have relatively simple control strategies for the regeneration process. The timing of regeneration initiation typically depends only on the unit's saturation state or a fixed time period, without being correlated with the overall energy state of the system. This non-coordinated control approach can easily lead to high-energy-consuming regeneration operations being performed when the system's energy supply is strained, thereby causing grid load fluctuations and reducing operational economics.

[0004] Meanwhile, the water purification process inevitably produces highly concentrated liquid. Traditional methods for treating this liquid often involve direct discharge, which not only wastes water resources but also easily impacts the environment. While some technical solutions attempt to treat this liquid, they typically require additional evaporation or crystallization equipment. This equipment itself is energy-intensive and requires significant investment, failing to achieve a closed-loop resource recovery system and making it difficult to reach the goal of zero liquid discharge. Summary of the Invention

[0005] To address the technical problems of low waste heat recovery efficiency, easy water pollution, high energy consumption in the purification process, and difficulty in achieving closed-loop zero discharge in high-temperature cooling water generated during the operation of high-temperature industrial equipment such as graphitization furnaces, this invention provides a collaborative control system that integrates energy cascade recovery, high-temperature online purification, and zero liquid discharge.

[0006] This invention provides a closed-loop cooling water purification and thermal energy cascade utilization system, the system comprising: An energy cascade coupling utilization module is used to release the thermal energy of high-temperature cooling water discharged from the graphitization furnace in a cascade manner.

[0007] A high-temperature current-changing capacitor deionization dynamic matrix purification module is installed on the bypass purification loop. The inlet of this bypass purification loop is located at the cooling water outlet of the graphitization furnace, and before the inlet of the energy cascade coupling utilization module. This structure is used to divert the uncooled high-temperature cooling water. The purified water outlet of the high-temperature current-changing capacitor deionization dynamic matrix purification module is connected to the inlet of the main circulating water pump.

[0008] A low-temperature membrane distillation zero-discharge module. The concentrate inlet of this module is connected to the regeneration drain outlet of a high-temperature current-varying capacitor deionization dynamic matrix purification module to treat the concentrate generated during the purification process. The cold-side feed inlet of this module is connected to the terminal heat energy outlet of an energy cascade coupling utilization module to utilize the low-temperature wastewater after cascade utilization. The pure water outlet of this module is connected to the inlet of the main circulating water pump to achieve water resource recovery.

[0009] A sensing and collaborative control module establishes electrical or communication connections with the aforementioned energy cascade coupling utilization module, high-temperature current-varying capacitor deionization dynamic matrix purification module, and low-temperature membrane distillation zero-emission module, respectively, for the collaborative regulation of the entire system's operation.

[0010] In one specific implementation, the energy cascade coupling utilization module includes tiered utilization units to maximize the value of thermal energy. It includes: The primary utilization unit is preferably an organic Rankine cycle (ORC) generator set. The primary utilization unit uses the high-grade heat energy carried by the high-temperature cooling water to generate electricity, converting heat energy into electrical energy.

[0011] The secondary utilization unit is located downstream of the primary utilization unit, and is preferably an absorption chiller unit. The secondary utilization unit uses the medium-temperature cooling water flowing out of the primary utilization unit to generate cooling capacity.

[0012] The tertiary utilization unit, located downstream of the secondary utilization unit, is preferably a terminal heat exchanger. The tertiary utilization unit recovers residual low-grade heat energy from the cooling water, for example, for plant heating or domestic hot water. The outlet of this tertiary utilization unit constitutes the terminal heat energy outlet, and the discharged low-temperature wastewater is supplied to the low-temperature membrane distillation zero-discharge module.

[0013] In one specific implementation, the high-temperature current-varying capacitor deionization dynamic matrix purification module, in order to achieve dynamic allocation of purification load, includes the following internal structure: Multiple high-temperature current-ratio capacitor deionization units are arranged in parallel.

[0014] There is one inlet main pipe and one outlet main pipe, and multiple high-temperature current-changing capacitor deionization units are installed between the inlet main pipe and the outlet main pipe.

[0015] To achieve independent control, each high-temperature current-varying capacitor deionization unit is equipped with a unit inlet isolation valve and a unit outlet isolation valve at its inlet and outlet. Both the unit inlet and outlet isolation valves are connected to a sensing and collaborative control module. The sensing and collaborative control module controls the opening and closing of these valves to enable independent operation or isolated regeneration of each high-temperature current-varying capacitor deionization unit.

[0016] In one specific implementation, to adapt to high-temperature and high-pressure operating conditions, each high-temperature current-ramp capacitor deionization unit includes: An electrode stack is provided, which consists of multiple high-temperature resistant porous electrodes and multiple ion-permeable separators stacked alternately. The high-temperature resistant porous electrodes are preferably made of a composite material of graphene and carbon nanotubes to provide high-temperature stability and high specific surface area.

[0017] A high-temperature, high-pressure resistant unit housing is used to encapsulate the electrode stack. The high-temperature, high-pressure resistant unit housing features a flow-through structure to guide cooling water vertically through the electrode stack, thereby improving mass transfer and purification efficiency.

[0018] In one specific embodiment, the low-temperature membrane distillation zero-discharge module is for the final treatment of the concentrate, and its internal structure includes: A hydrophobic microporous membrane is used to isolate liquid water while allowing water vapor to pass through.

[0019] A hot-side flow channel is located on the hot side of the hydrophobic microporous membrane. Its inlet is connected to the inlet of the low-temperature membrane distillation zero-discharge concentrate, and is used to guide the high-temperature, high-concentration concentrate from the high-temperature current-varying capacitor deionization dynamic matrix purification module through it.

[0020] A cold-side flow channel is located on the cold side of the hydrophobic microporous membrane. Its inlet is connected to the cold-side feed port to guide the flow of low-temperature waste water from the energy cascade coupling utilization module, thereby condensing the water vapor passing through the membrane. The outlet of the cold-side flow channel is connected to the pure water outlet.

[0021] A solid discharge port is located at the end of the hot-side flow channel to discharge the solid salts that precipitate after the water evaporates.

[0022] To achieve a high degree of energy self-sufficiency in the system, the present invention may further include an energy self-sufficiency connection path. This energy self-sufficiency connection path electrically connects the power output terminal of the first-level utilization unit in the energy cascade coupling utilization module to the power receiving terminal of the sensing and collaborative control module and the DC power supply module of the high-temperature current-varying capacitor deionization dynamic matrix purification module, respectively, to provide operating power for the core control unit and purification unit of the system.

[0023] One of the core innovations of this invention lies in the intelligent collaborative control logic of the sensing and collaborative control module, which is configured to execute a specific algorithm: On one hand, the sensing and collaborative control module incorporates a dynamic adjustment algorithm for purification load. This module monitors water quality in real time through sensors deployed on the main cooling circulation loop. Based on the deviation between the monitored real-time water conductivity and the preset target conductivity, the algorithm dynamically calculates the optimal number of high-temperature current-varying capacitor deionization units required for the current operating conditions. Subsequently, the sensing and collaborative control module sends opening commands to the inlet and outlet isolation valves of the corresponding units, putting them into operation while keeping the remaining units offline and in standby mode. This achieves on-demand purification and reduces system energy consumption.

[0024] On the other hand, the sensing and collaborative control module is equipped with a regeneration decision algorithm. To achieve independent state monitoring of the high-temperature current-varying capacitor deionization unit, the sensing and collaborative control module is connected to a sensor network, which individually sets up a corresponding outlet conductivity sensor at the purified water outlet of each high-temperature current-varying capacitor deionization unit. The sensing and collaborative control module determines whether the high-temperature current-varying capacitor deionization unit has reached adsorption saturation by monitoring the signal of the outlet conductivity sensor (e.g., the outlet conductivity no longer decreases or begins to increase), and generates a corresponding regeneration request status.

[0025] When determining the regeneration timing, a regeneration decision algorithm is activated to determine whether to execute a regeneration command on the high-temperature current-ramp-capacitor (HTVC) deionization unit that has issued a regeneration request. The decision logic is as follows: the sensing and collaborative control module acquires the regeneration request status of the HTVC deionization unit in real time, and simultaneously acquires the real-time output power of the first-level utilization unit in the energy cascade coupling utilization module. The sensing and collaborative control module sends a regeneration execution command to the HTVC deionization unit only if the HTVC deionization unit's regeneration request status is "requesting regeneration" and the acquired real-time output power is greater than a preset power threshold. This logic ensures that the energy-consuming regeneration process is prioritized during periods of sufficient system energy (i.e., high ORC power generation), enhancing the system's energy coordination and economy.

[0026] Furthermore, the sensing and collaborative control module is configured to send precise voltage control commands to the corresponding independent DC power supply module based on the operating stage of the high-temperature current-ratio capacitor deionization unit. For example, a forward adsorption voltage is applied when the unit is in the adsorption stage, and a reverse desorption voltage is applied when the unit is in the regeneration stage, to complete the ion adsorption and desorption cycle.

[0027] This invention provides a closed-loop cooling water purification and thermal energy cascade utilization system. It has the following beneficial effects: 1. This invention sets up an energy cascade coupling utilization module to utilize the thermal energy of high-temperature cooling water in stages according to its grade. Through a first-stage organic Rankine cycle generator set, a second-stage absorption chiller unit, and a third-stage terminal heat exchanger, it realizes the cascade recovery of high-value electrical energy, cooling capacity, and low-grade thermal energy. At the same time, through an energy self-sustaining connection path, it uses self-generated electricity to power the purification module and control module in the system, thereby improving energy utilization efficiency and reducing the system's dependence on external energy.

[0028] 2. This invention achieves intelligent coordination between the purification process and energy state through a regeneration decision algorithm built into the sensing and collaborative control module. The regeneration decision algorithm not only determines the regeneration demand based on the saturated regeneration request state of the high-temperature current-varying capacitor deionization unit, but also monitors the real-time output power of the energy cascade coupling utilization module. This avoids high-energy-consuming regeneration during periods of energy scarcity, optimizing the overall energy flow distribution and operational economy of the system.

[0029] 3. This invention uses a low-temperature membrane distillation zero-discharge module to finally treat the high-concentration concentrate discharged during the regeneration of the high-temperature current-changing capacitor deionization dynamic matrix purification module. It utilizes energy cascade coupling to use the low-temperature waste water discharged from the end of the module as the condensate required for its operation. The waste heat energy inside the system drives the distillation process, and pure water can be recovered and solid salts separated without additional energy consumption, realizing the closed-loop utilization of water resources and zero liquid discharge of the system. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall system structure of the present invention; Figure 2 This is a schematic diagram of the internal structure and flow path of the energy cascade coupling utilization module of the present invention; Figure 3 This is a schematic diagram of the high-temperature current-varying capacitor deionization dynamic matrix purification module of the present invention; Figure 4 This is a schematic diagram illustrating the working principle of the low-temperature membrane distillation zero-emission module of the present invention. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Please see the appendix Figure 1 The present invention provides a closed-loop cooling water purification and thermal energy cascade utilization system, including an energy cascade coupling utilization module; a high-temperature current-varying capacitor deionization dynamic matrix purification module; a low-temperature membrane distillation zero-emission module; and a sensing and collaborative control module.

[0033] The energy cascade coupling and utilization module is installed on the main cooling circulation loop between the cooling water outlet of the graphitization furnace and the main circulating water pump. The high-temperature cooling water discharged from the graphitization furnace first flows into the energy cascade coupling and utilization module. After the heat energy is released in stages in the energy cascade coupling and utilization module, the cooled water flows out and merges into the inlet of the main circulating water pump.

[0034] The high-temperature current-changing capacitor deionization dynamic matrix purification module is installed on the bypass purification loop. The inlet of the bypass purification loop is located at the cooling water outlet of the graphitization furnace, i.e., before the inlet of the energy cascade coupling utilization module, to guide the flow of high-temperature cooling water. The purified water outlet of the high-temperature current-changing capacitor deionization dynamic matrix purification module is connected to the inlet of the main circulating water pump, i.e., after the outlet of the energy cascade coupling utilization module.

[0035] The concentrate inlet of the low-temperature membrane distillation zero-emission module is connected to the regeneration discharge port of the high-temperature current-varying capacitor deionization dynamic matrix purification module through a pipeline, and is used to receive the high-temperature, high-concentration concentrate generated by the high-temperature current-varying capacitor deionization dynamic matrix purification module during the regeneration process.

[0036] The cold-side inlet of the cryogenic membrane distillation zero-emission module is connected to the terminal heat outlet of the energy cascade coupling utilization module via a pipeline to receive the cryogenic wastewater discharged from the energy cascade coupling utilization module as condensate. The pure water outlet of the cryogenic membrane distillation zero-emission module is connected to the inlet of the main circulating water pump or the cooling water makeup line via a pipeline for the recovery of pure water.

[0037] The sensing and collaborative control module establishes electrical or communication connections with the energy cascade coupling utilization module, the high-temperature current-varying capacitor deionization dynamic matrix purification module, and the low-temperature membrane distillation zero-emission module, respectively.

[0038] The sensing and collaborative control module collects system operating parameters in real time through sensors (such as conductivity sensors, temperature sensors, and power sensors) deployed in the main cooling water circuit and at key nodes of each module. Based on the collected operating parameters, the sensing and collaborative control module sends control commands to the actuators (such as power modules and isolation valves) of the high-temperature current-ratio capacitive deionization dynamic matrix purification module to adjust the number of working units and the regeneration timing of the high-temperature current-ratio capacitive deionization dynamic matrix purification module.

[0039] The sensing and collaborative control module incorporates a dynamic adjustment algorithm for the purification load. This algorithm is used to adjust the purification load based on the real-time water conductivity of the main cooling water circuit. With the preset target conductivity To address deviations, the number of high-temperature current-ramp capacitor deionization units put into operation is dynamically adjusted. . Determined by the following formula: ; Among them, when The formula is activated at that time; The number of high-temperature current-ramp capacitor deionization units that are dynamically activated and put into operation is a dimensionless integer. The total number of units in the high-temperature current-changing capacitor deionization dynamic matrix purification module is a dimensionless integer. The minimum number of working units required for the system to maintain operation, which is a dimensionless integer; The real-time conductivity measurement value of the main cooling water circuit is expressed in μS / cm. The preset target conductivity of the cooling water is expressed in μS / cm. This is a monotonically increasing control function that maps the conductivity deviation to the required number of cells; This is the floor function.

[0040] The sensing and collaborative control module incorporates a regeneration decision algorithm. This algorithm is used to determine the regeneration decision based on the dynamic matrix purification module's high-temperature current-variable capacitor deionization process. Regeneration request status of a high-temperature current-ramp capacitor deionization unit Real-time output power of ORC generator set in energy cascade coupling utilization module Determine the first Regeneration execution command for each unit . Determined by the following logical formula: ; in, For the first The regeneration execution command for each unit, 1 represents execution, and 0 represents no execution; For the first The status of the regeneration request issued by each unit, where 1 represents a request for regeneration and 0 represents no request. This represents the real-time output power of the ORC generator set, in kW. The power threshold used to determine whether the system has excess energy is expressed in kW. The logical formula means: if and only if the first... The sensing and coordination control module only sends a regeneration request to the first high-temperature current-ramp capacitor deionization unit when the real-time output power of the ORC generator set exceeds the power threshold. Each unit sends a regeneration execution command.

[0041] The closed-loop cooling water purification and thermal energy cascade utilization system in this embodiment of the invention includes a main cooling circulation loop. The main cooling circulation loop includes: a pipe located at the outlet of the graphitization furnace cooling jacket, connected to the high-temperature fluid inlet of the energy cascade coupling utilization module; a low-temperature fluid outlet of the energy cascade coupling utilization module, connected via a pipe to the inlet of a main circulating water pump; and the outlet of the main circulating water pump, connected via a pipe back to the inlet of the graphitization furnace cooling jacket. The main cooling circulation loop constitutes a closed-loop fluid circulation system for exporting and cascading the thermal energy generated by the graphitization furnace.

[0042] The closed-loop cooling water purification and thermal energy cascade utilization system further includes a bypass purification circulation loop. The bypass purification circulation loop is used to divert a portion of the high-temperature cooling water in the main cooling circulation loop and purify the high-temperature cooling water.

[0043] The bypass inlet of the bypass purification circulation loop is located on the main circuit pipeline between the outlet of the graphitization furnace cooling jacket and the high-temperature fluid inlet of the energy cascade coupling utilization module. This arrangement ensures that the bypass purification circulation loop draws high-temperature cooling water that has not been cooled by the energy cascade coupling utilization module.

[0044] In the bypass purification circulation loop, a bypass booster pump and a bypass flow regulating valve can be further installed after the bypass inlet. The bypass booster pump provides the pressure head required to overcome flow resistance for the cooling water flowing through the high-temperature current-varying capacitor deionization dynamic matrix purification module. The bypass flow regulating valve (e.g., an electrically operated regulating valve controlled by a sensing and coordination control module) precisely controls the fluid volume entering the high-temperature current-varying capacitor deionization dynamic matrix purification module according to real-time purification requirements.

[0045] The bypass purification circulation loop's piping, after flowing through the bypass booster pump and bypass flow regulating valve, connects to the purification inlet of the high-temperature current-varying capacitor deionization dynamic matrix purification module. The purification water outlet of the high-temperature current-varying capacitor deionization dynamic matrix purification module is connected to the inlet of the main circulating water pump via piping, channeling the purified high-temperature soft water into the low-temperature side of the main cooling circulation loop, downstream of the energy cascade coupling utilization module.

[0046] The cooling water closed-loop purification and thermal energy cascade utilization system further includes a zero-discharge treatment flow path. This zero-discharge treatment flow path collects and treats the high-concentration concentrate discharged from the high-temperature current-ratio capacitor deionization dynamic matrix purification module during the regeneration phase. The zero-discharge treatment flow path is equipped with a regeneration drain manifold, which connects to the regeneration drain ports of each high-temperature current-ratio capacitor deionization unit in the high-temperature current-ratio capacitor deionization dynamic matrix purification module. The outlet of the regeneration drain manifold connects to the hot-side feed port of the low-temperature membrane distillation zero-discharge module. The zero-discharge treatment flow path operates intermittently, only activating when the high-temperature current-ratio capacitor deionization unit performs regeneration operations, transporting the high-temperature, high-concentration concentrate to the low-temperature membrane distillation zero-discharge module.

[0047] The cooling water closed-loop purification and thermal energy cascade utilization system further includes specific flow paths for achieving inter-module synergy. The first synergistic flow path is the cryogenic membrane distillation cold source supply path. The wastewater outlet of the tertiary utilization unit (i.e., the terminal heat exchanger) of the energy cascade coupling utilization module is connected via piping to the cold-side inlet of the cryogenic membrane distillation zero-emission module. The cold-side outlet of the cryogenic membrane distillation zero-emission module is then connected via piping back to the inlet of the main circulating water pump. This flow path utilizes the terminal cryogenic wastewater of the energy cascade coupling utilization module to provide the cooling capacity required for vapor condensation in the cryogenic membrane distillation zero-emission module.

[0048] The second collaborative flow path is the pure water recovery flow path. The pure water (permeate) outlet of the low-temperature membrane distillation zero-discharge module is connected to the makeup water line of the main cooling circulation loop or the inlet of the main circulating water pump via a pipeline. This flow path is used to replenish the main cooling circulation loop with the high-purity water recovered by the low-temperature membrane distillation zero-discharge module, realizing the closed-loop utilization of the system's water resources.

[0049] The cooling water closed-loop purification and thermal energy cascade utilization system includes an energy self-sufficient connection path. The power output terminal of the primary utilization unit (i.e., the Organic Rankine Cycle (ORC) generator set) within the energy cascade coupling utilization module is connected to the power receiving terminal of the sensing and collaborative control module via a power cable, and further connected to the independent DC power supply modules of each high-temperature current-changing capacitor deionization unit in the high-temperature current-changing capacitor deionization dynamic matrix purification module via a power distribution unit. The operating power of auxiliary electrical equipment such as the sensing and collaborative control module, main circulating water pump, and bypass booster pump can also be obtained from the power output terminal of the ORC generator set, thereby achieving a high degree of energy self-sufficiency for the system.

[0050] The cooling water closed-loop purification and thermal energy cascade utilization system includes a sensor signal connection network. The sensing and coordinated control module is equipped with analog and digital input interfaces to receive sensor data from various deployment points of the cooling water closed-loop purification and thermal energy cascade utilization system.

[0051] Online conductivity, temperature, and pH sensors deployed in the main cooling circulation loop (e.g., at the inlet of the main circulating water pump) transmit the measured analog signals (e.g., 4–20 mA standard current signals) or digital signals (e.g., RS485 signals) to the corresponding input interfaces of the sensing and coordination control module via signal cables. The sensing and coordination control module then obtains... value.

[0052] Power sensors (or power meters) deployed at the energy cascade coupling utilization module (e.g., the power output terminal of an ORC generator set) measure the real-time output power. The signal is transmitted to the corresponding input interface of the sensing and collaborative control module.

[0053] To accurately determine the saturation state of the high-temperature current-ratio capacitive deionization (HTVC) units, an individual outlet conductivity sensor can be installed at the purified water outlet of each HTVC deionization unit in the dynamic matrix purification module. The measurement signals from these outlet conductivity sensors are all connected to the sensing and collaborative control module. The sensing and collaborative control module determines the saturation state of a single HTVC deionization unit by monitoring the change in outlet conductivity over time (e.g., the outlet conductivity no longer decreasing or begins to increase), and generates a regeneration request status. .

[0054] The cooling water closed-loop purification and thermal energy cascade utilization system includes a control signal connection network. The sensing and collaborative control module is equipped with analog output interfaces and digital output interfaces (or relay output interfaces) for sending control commands to the actuators in the system.

[0055] The digital output interface of the sensing and collaborative control module is connected via a control cable to the electrical actuators of the inlet and outlet automatic isolation valves of each high-temperature current-varying capacitor deionization unit in the high-temperature current-varying capacitor deionization dynamic matrix purification module. The sensing and collaborative control module outputs switching signals to control the opening or closing of the automatic isolation valves, thereby enabling online activation, bypass isolation, or regeneration switching of individual high-temperature current-varying capacitor deionization units.

[0056] The analog output interface (e.g., 0-10V voltage signal or 4-20mA current signal) or communication interface (e.g., Modbus-RTU) of the sensing and collaborative control module is connected to the independent DC power supply module of each high-temperature current-ratio capacitor deionization unit in the high-temperature current-ratio capacitor deionization dynamic matrix purification module. Through this connection, the sensing and collaborative control module precisely sets the output parameters of the independent DC power supply module, for example, applying a positive adsorption voltage during the adsorption stage and a reverse desorption voltage during the regeneration stage.

[0057] The control output interface of the sensing and coordinated control module is further connected to the actuator of the bypass flow regulating valve on the bypass purification circulation loop, as well as the frequency converters of the main circulating water pump and the bypass booster pump. This connection enables the sensing and coordinated control module to adjust the flow rate according to the purification load (e.g., ...). Based on the quantity and system operating status, adjust the flow rate of the bypass purification circulation loop and the circulation rate of the main cooling circulation loop.

[0058] See attached document Figure 2 The energy cascade coupling utilization module includes a primary utilization unit. The primary utilization unit is preferably an organic Rankine cycle (ORC) generator set. The primary utilization unit converts the high-grade heat energy carried by the high-temperature cooling water discharged from the graphitization furnace into electrical energy.

[0059] The primary utilization unit, namely the organic Rankine cycle generator set, constitutes a closed thermodynamic cycle using a low-boiling-point organic working fluid. Specifically, the primary utilization unit includes an evaporator, a turboexpander, a generator, a condenser, and a working fluid pump.

[0060] The evaporator is the heat-absorbing component of the primary utilization unit. It is a heat exchanger with two independent fluid channels, such as a shell-and-tube heat exchanger or a plate heat exchanger. The inlet of the first fluid channel (heat source side) of the evaporator is connected to the main circuit pipeline of the cooling jacket outlet of the graphitization furnace, for introducing high-temperature cooling water; the outlet of the first fluid channel is connected to the inlet of the secondary utilization unit of the energy cascade coupling utilization module, for discharging medium-temperature cooling water that has released some heat energy. The second fluid channel (working fluid side) of the evaporator contains the organic working fluid.

[0061] The turbine expander is mechanically coupled to the generator. The inlet of the turbine expander is connected to the outlet of the second fluid passage of the evaporator to receive high-temperature, high-pressure organic working fluid vapor.

[0062] The condenser is the heat-exhausting component of the primary utilization unit. The condenser inlet is connected to the outlet of the turbine expander to receive the low-pressure organic working fluid vapor discharged after the turbine expander has performed its work. The condenser has a cooling passage for introducing an external cooling medium (such as ambient air or independent cooling water).

[0063] The inlet of the working fluid pump is connected to the outlet of the condenser, and the outlet of the working fluid pump is connected to the inlet of the second fluid channel of the evaporator. This is used to pressurize the condensed liquid organic working fluid and transport it back to the evaporator.

[0064] During the operation of the primary utilization unit, high-temperature cooling water drawn from the graphitization furnace flows into the first fluid channel of the evaporator. Inside the evaporator, the heat energy of the high-temperature cooling water is transferred to the liquid organic working fluid in the second fluid channel, causing the organic working fluid to transform into high-temperature, high-pressure steam. The high-temperature, high-pressure organic working fluid steam enters the turbine expander, driving the turbine expander to rotate and perform work. The rotation of the turbine expander drives the generator to rotate, thereby outputting electrical energy. The low-pressure organic working fluid steam after performing work is discharged from the turbine expander and enters the condenser, where it is cooled by the external cooling medium and condenses into a liquid state. The liquid organic working fluid is pressurized by the working fluid pump and then sent back to the evaporator, completing the internal thermodynamic cycle of the primary utilization unit.

[0065] The generator's power output terminal is connected to the power receiving terminal of the sensing and collaborative control module via a power cable, which is used to supply power to the electrical equipment (including the high-temperature current transformer deionization dynamic matrix purification module and the sensing and collaborative control module itself) within the cooling water closed-loop purification and thermal energy cascade utilization system.

[0066] The energy cascade coupling utilization module further includes a secondary utilization unit, which is preferably an absorption chiller unit, such as a lithium bromide absorption chiller unit.

[0067] The heat source inlet of the secondary utilization unit is connected via a pipeline to the first fluid channel outlet of the evaporator of the primary utilization unit (i.e., the organic Rankine cycle generator set) to receive the medium-temperature cooling water flowing out of the primary utilization unit. The heat source outlet of the secondary utilization unit is connected via a pipeline to the inlet of the tertiary utilization unit of the energy cascade coupling utilization module.

[0068] The secondary utilization unit utilizes the heat energy carried by the medium-temperature cooling water to produce chilled water with a cooling effect. The secondary utilization unit (i.e., absorption chiller) mainly includes a generator, an absorber, a condenser, and an evaporator.

[0069] The generator, absorber, condenser, and evaporator are interconnected by internal piping to form a thermodynamic refrigeration system that uses a refrigerant (e.g., water) and an absorbent (e.g., lithium bromide solution) to circulate.

[0070] The generator is equipped with a heat source fluid channel. This channel is the passage through which the medium-temperature cooling water flows in the secondary utilization unit. As the medium-temperature cooling water flows through the heat source fluid channel, it transfers its heat energy to the dilute absorbent solution inside the generator, causing the refrigerant in the solution to evaporate and form high-temperature, high-pressure refrigerant vapor. The cooling water, having released its heat energy, flows out from the outlet of the heat source fluid channel (i.e., the heat source outlet of the secondary utilization unit) and enters the tertiary utilization unit.

[0071] The evaporator has a separate refrigerant water flow channel. This channel connects to external processes or areas requiring cooling. Liquid refrigerant from the condenser evaporates under the low-pressure environment inside the evaporator. This evaporation process absorbs heat from the refrigerant water flow channel, thus lowering the temperature of the refrigerant water flowing through it and generating cooling.

[0072] Both the condenser and absorber are equipped with external cooling water channels. These channels are used to supply cooling water from an external cooling tower. The condenser condenses the high-temperature, high-pressure refrigerant vapor generated by the generator into liquid refrigerant. The absorber reabsorbs the low-pressure refrigerant vapor generated by the evaporator back into the concentrated absorbent solution; this absorption process is exothermic. The cooling water from the external cooling tower removes the heat released during the condensation and absorption processes.

[0073] The energy cascade coupling utilization module further includes a tertiary utilization unit, which is located downstream of the heat source outlet of the secondary utilization unit. The tertiary utilization unit is preferably a set of terminal heat exchangers, such as a plate heat exchanger or a shell-and-tube heat exchanger.

[0074] The tertiary utilization unit is used to recover residual low-grade heat energy in the cooling water. The tertiary utilization unit is equipped with a first fluid channel (heat source side) and a second fluid channel (heat user side).

[0075] The inlet of the first fluid channel of the tertiary utilization unit is connected to the heat source outlet of the secondary utilization unit (i.e., the absorption chiller) via a pipeline. Cooling water flowing out of the secondary utilization unit, with its temperature further reduced, flows into the first fluid channel.

[0076] The second fluid channel of the tertiary utilization unit is used to connect to an independent external heat user circuit. This external heat user circuit could be, for example, a plant heating circuit or a domestic hot water supply circuit.

[0077] Inside the tertiary utilization unit, the cooling water flowing through the first fluid channel transfers its low-grade heat energy to the external heat user circuit medium flowing through the second fluid channel, thereby achieving the final utilization of the heat energy.

[0078] The outlet of the first fluid channel of the three-stage utilization unit is the final wastewater outlet of the energy cascade coupling utilization module. This final wastewater outlet is connected via a pipeline to the cold-side inlet of the cryogenic membrane distillation zero-discharge module. This connection supplies the cryogenic wastewater, after all stages of thermal energy utilization have been completed, to the cryogenic membrane distillation zero-discharge module as the condensate required for its operation.

[0079] See attached document Figure 3 The high-temperature current-changing capacitor deionization dynamic matrix purification module is the core purification component of the cooling water closed-loop purification and thermal energy cascade utilization system. It is used to directly desalinate and purify the high-temperature cooling water drawn from the bypass purification circulation loop.

[0080] The high-temperature current-ratio capacitor deionization dynamic matrix purification module comprises N (N is an integer greater than or equal to 2) structurally identical, independently operable high-temperature current-ratio capacitor deionization units. The N high-temperature current-ratio capacitor deionization units are arranged in parallel.

[0081] The high-temperature current-variable capacitor deionization dynamic matrix purification module is equipped with one main purification inlet and one main purification outlet. The main purification inlet is connected to a main inlet pipe (or inlet manifold), and the main purification outlet is connected to a main outlet pipe (or outlet manifold). N high-temperature current-variable capacitor deionization units are installed between the main inlet pipe and the main outlet pipe.

[0082] Each high-temperature current-variable capacitor deionization unit is equipped with an independent unit inlet and an independent unit outlet. The unit inlet is connected to the main inlet pipe via a branch line. The unit outlet is connected to the main outlet pipe via a branch line.

[0083] To enable independent control of each high-temperature current-changing capacitor deionization unit, a unit inlet isolation valve is installed on the branch pipeline connecting to the unit inlet; and a unit outlet isolation valve is installed on the branch pipeline connecting to the unit outlet.

[0084] Both the unit inlet isolation valve and the unit outlet isolation valve are automatic valves, such as solenoid valves or pneumatic valves with electric positioners. The electrical actuators of the automatic valves are electrically connected to the digital output interface of the sensing and coordinated control module.

[0085] The sensing and coordinated control module can put the corresponding high-temperature current-varying capacitor deionization unit into online operation by sending opening commands to the designated unit inlet and outlet isolation valves. Conversely, by sending a closing command, the module can isolate the corresponding high-temperature current-varying capacitor deionization unit from the parallel matrix for standby, maintenance, or regeneration operations. This matrix-style parallel layout and automatic valve system allows the sensing and coordinated control module to dynamically adjust the number of online operating units (i.e.,...). This provides a physical basis, enabling the purification flux to be flexibly adjusted according to real-time water quality changes, and the regeneration process of a single unit does not affect the normal purification work of other units.

[0086] Each high-temperature current-ratio capacitor deionization unit in the high-temperature current-ratio capacitor deionization dynamic matrix purification module has a fine internal structure for electrochemical desalination under high-temperature conditions.

[0087] The core component inside the high-temperature current-ratio capacitor deionization unit is an electrode stack. The electrode stack consists of multiple high-temperature resistant porous electrodes and multiple ion-permeable partitions stacked alternately.

[0088] The high-temperature resistant porous electrode comprises an anode electrode and a cathode electrode. The electrode is made of a composite material of graphene and carbon nanotubes, which is supported on a conductive and high-temperature corrosion-resistant porous substrate, such as titanium felt or graphite felt. This structure endows the high-temperature resistant porous electrode with stable physicochemical properties in high-temperature aquatic environments, as well as a large specific surface area for electrostatic adsorption of ions.

[0089] The ion-permeable separator is an electrically insulating material placed between adjacent anode and cathode electrodes to prevent physical contact between the electrodes that could lead to a short circuit. The separator is made of high-temperature resistant polymer-modified materials or porous ceramic materials, with an interconnected microporous structure that allows ions in the water to migrate freely under the influence of an electric field.

[0090] The electrode stack is arranged in a flow-through structure. In this structure, the flow direction of cooling water is generally perpendicular to the main surface of the high-temperature porous electrode. Guide plates are provided at both ends of the electrode stack. These guide plates distribute the cooling water flowing in from the unit inlet evenly across the entire cross-section of the electrode stack and guide the cooling water vertically through the alternating high-temperature porous electrodes and ion-permeable partitions within the stack, finally converging at the unit outlet. This flow-through structure maximizes the contact area and contact time between the cooling water and the high-temperature porous electrode material, thereby achieving high purification efficiency.

[0091] The electrode stack is encapsulated within a high-temperature, high-pressure resistant unit housing. The housing is made of a special engineering plastic (such as polyetheretherketone PEEK or polytetrafluoroethylene PTFE) or a corrosion-resistant alloy with high chemical inertness and mechanical strength. The housing is sealed to the unit inlet, outlet, and external electrode terminals using high-temperature resistant seals (such as fluororubber FKM or perfluororubber FFKM sealing rings) to ensure no fluid leakage under high-temperature and high-pressure conditions.

[0092] The high-temperature current-ratio capacitor deionization unit has a pre-installed thermally assisted regeneration interface on its outer casing. This interface is a microfluidic port connected to an external fluid pipeline via a miniature valve controlled by a sensing and co-control module. During regeneration, the miniature valve opens, allowing a small amount of cryogenic fluid (e.g., cryogenic pure water from a cryogenic membrane distillation zero-discharge module) to be instantaneously injected into the isolated high-temperature current-ratio capacitor deionization unit. The cryogenic fluid and the high-temperature electrode surface create a localized temperature difference, which, in conjunction with a reverse electric field, promotes the efficient desorption of adsorbed ions from the electrode surface.

[0093] See attached document Figure 4 The low-temperature membrane distillation zero-emission module is used to perform final treatment on the high-temperature, high-concentration concentrate discharged from the high-temperature current-varying capacitor deionization dynamic matrix purification module, in order to recover the water and separate the solid salts.

[0094] The cryogenic membrane distillation zero-emission module includes one or more membrane modules. In one embodiment, the membrane module is configured as a direct contact membrane distillation (DCMD) module. In another embodiment, the membrane module is configured as an air gap membrane distillation (AGMD) module.

[0095] The core component of the membrane module is a hydrophobic microporous membrane. The hydrophobic microporous membrane is made of a polymer that exhibits high chemical and thermal stability under high temperature and high salt conditions. In one embodiment, the hydrophobic microporous membrane is made of polytetrafluoroethylene (PTFE). In another embodiment, the hydrophobic microporous membrane is made of hydrophobically modified polyvinylidene fluoride (PVDF) or polypropylene (PP).

[0096] The surface of the hydrophobic microporous membrane is highly hydrophobic, with a static contact angle with water greater than 90 degrees. This physical property ensures that liquid water and its dissolved ions and non-volatile impurities are physically blocked on one side of the hydrophobic microporous membrane (i.e., the hot side), allowing only water molecules (water vapor) in gaseous form to pass through the micropores of the hydrophobic microporous membrane.

[0097] Hydrophobic microporous membranes possess a defined microporous structure. The average pore size of the microporous structure ranges from 0.1 micrometers to 1.0 micrometers. This pore size range ensures sufficient transport flux of water vapor molecules while generating sufficient capillary forces to prevent liquid water from penetrating the membrane pores under high pressure differential, thus preventing membrane wetting.

[0098] In one specific embodiment, the membrane module employs a plate-and-frame structure. This structure includes alternating stacks of hydrophobic microporous membranes, hot-side flow channels, and cold-side flow channels. Both the hot-side and cold-side flow channels are machined with guide grooves to guide fluid flow, creating turbulent or uniform laminar flow on the surface of the hydrophobic microporous membranes. The hydrophobic microporous membranes, hot-side flow channels, and cold-side flow channels are separated and sealed using chemically resistant gaskets. The entire stack is compressed by metal end plates at both ends using fastening bolts, forming a leak-free, integrated module capable of withstanding operating pressures and temperatures.

[0099] The design of the internal flow channels and external interfaces of the low-temperature membrane distillation zero-emission module aims to achieve effective separation and transport of the hot-side concentrate, the cold-side condensate, the produced pure water, and the final concentrate.

[0100] The low-temperature membrane distillation zero-emission module is equipped with a hot-side flow channel. The inlet of the hot-side flow channel is also the hot-side feed port of the low-temperature membrane distillation zero-emission module, which is connected to the regeneration drain main of the high-temperature current-varying capacitor deionization dynamic matrix purification module via a pipeline. The hot-side flow channel guides the high-temperature, high-concentration concentrate to flow on the hot-side surface of the hydrophobic microporous membrane. The design of the hot-side flow channel takes into account the corrosiveness and scaling tendency of the high-temperature, high-concentration concentrate being treated; its material can be an alloy or polymer material resistant to chloride ion corrosion. A turbulence-enhancing structure can be incorporated inside the hot-side flow channel to enhance fluid turbulence, improve heat and mass transfer efficiency, and slow down the rate of scaling on the membrane surface.

[0101] The cryogenic membrane distillation zero-emission module is equipped with a cold-side flow channel. The inlet of the cold-side flow channel is also the cold-side feed port of the cryogenic membrane distillation zero-emission module, which is connected via piping to the waste water outlet of the third-stage utilization unit of the energy cascade coupling utilization module. The cold-side flow channel guides the cryogenic waste water to flow on the cold side of the hydrophobic microporous membrane to absorb and condense water vapor passing through the membrane. The geometry of the cold-side flow channel is designed to maximize the condensation surface area and heat exchange efficiency. In direct-contact membrane distillation units, the cold-side flow channel guides the cryogenic waste water to directly contact the condensation-side surface of the hydrophobic microporous membrane.

[0102] The low-temperature membrane distillation zero-discharge module is equipped with a pure water outlet. This outlet collects the pure water condensed in the cold-side channel and mixed with the low-temperature waste water. In the direct-contact membrane distillation unit, the outlet of the cold-side channel constitutes the pure water outlet. The pure water outlet is connected via piping to the makeup water line of the main cooling circulation loop or the inlet of the main circulating water pump to replenish the main cooling circulation loop with the recovered pure water.

[0103] The low-temperature membrane distillation zero-discharge module further includes a solids discharge port. The solids discharge port is located at the end of the hot-side flow channel and communicates with a crystallizer or concentration tank for discharging the final salt content. In one embodiment, the bottom of the concentration tank is designed to be conical and equipped with a sludge discharge valve for intermittently discharging high-solids-content salt sludge. In another embodiment, the low-temperature membrane distillation zero-discharge module integrates a scraper-type or screw-type crystallizer, which actively separates solid salt crystals from the supersaturated solution flowing through the end of the hot-side flow channel and mechanically discharges the solid salt crystals from the low-temperature membrane distillation zero-discharge module, thereby achieving zero liquid discharge.

[0104] Reference Figure 1 - Figure 4 The physical core of the sensing and collaborative control module is a hardware platform, which is a central controller. The central controller is used to execute pre-programmed control logic to process the received sensor signals and generate control commands for the actuators.

[0105] In one embodiment, the central controller is a modular programmable logic controller (PLC). In another embodiment, the central controller is the master controller in a distributed control system (DCS).

[0106] The central controller includes a central processing unit (CPU) module. The CPU module integrates a microprocessor and memory (including program memory and data memory) to execute control programs, including algorithms for dynamic adjustment of the purification load and regeneration decision-making.

[0107] The central controller further includes multiple input / output modules, which are physically mounted on a baseboard or rack that communicates with the central processing unit module. The input / output modules specifically include: One or more analog input modules are used to receive continuously changing analog signals. For example, the analog input modules can convert standard 4-20 mA current signals received from online conductivity sensors, temperature sensors, pH sensors, and power sensors of ORC generator sets into digital values ​​for processing by the central processing unit module.

[0108] One or more digital input modules are used to receive switch status signals. For example, the digital input modules are used to receive position feedback signals (fully open / fully closed status) of each automatic isolation valve in the high-temperature current-varying capacitor deionization dynamic matrix purification module, or the operating status signal of the main circulating water pump.

[0109] One or more analog output modules are used to send continuously varying control signals. For example, based on calculations by the central processing unit module, the analog output module outputs a 0-10 volt (V) or 4-20 mA signal to the independent DC power supply module of the high-temperature current-ramp capacitor deionization unit to precisely set its output voltage during the adsorption or regeneration phase. The analog output module can also send frequency setting signals to the frequency converter driver of the main circulating water pump or bypass booster pump.

[0110] One or more digital output modules (e.g., relay output modules) are used to send switching control commands. For example, the digital output modules send energizing or de-energizing commands to the solenoid coils or electric actuators of the unit inlet isolation valve and the unit outlet isolation valve of the high-temperature current-varying capacitor deionization unit according to the instructions of the central processing unit module, so as to control their opening or closing.

[0111] The central controller also includes a power supply module, which converts external power into a stable DC voltage to provide the necessary power for the operation of the central processing unit module and various input / output modules. The central controller may also be configured with a communication module for exchanging data with a host computer or human-machine interface (HMI) via industrial Ethernet or fieldbus protocols (such as Modbus or Profibus).

[0112] The sensing and collaborative control module includes a sensor network as its perception layer. The sensor network consists of a series of sensors deployed at various key physical nodes of the cooling water closed-loop purification and thermal energy cascade utilization system, used to collect system operating status parameters in real time and continuously, and transmit these parameters to the central controller in the form of electrical signals.

[0113] The sensor network includes a main loop water quality monitoring unit. This unit is deployed at the inlet of the main circulating water pump; cooling water samples collected at this location represent the state of the mixed water before it re-enters the graphitization furnace after purification and heat recovery. The main loop water quality monitoring unit specifically includes: An online conductivity sensor measures the conductivity as the real-time input value in the dynamic adjustment algorithm for the purification load. ; An online temperature sensor measures values ​​used to compensate for temperature readings from a conductivity sensor and monitor the cooling efficiency of the main circuit. An online pH sensor is used to monitor the acidity or alkalinity of cooling water to provide early warning of potential corrosion risks.

[0114] The sensor network includes an energy state monitoring unit (ESM). The ESM is deployed at the power output of the primary utilization unit (i.e., the Organic Rankine Cycle (ORC) generator set). Specifically, the ESM is either an electrical parameter measuring instrument or a power sensor that measures the real-time output power of the ORC generator set. This measurement is transmitted to the central controller and used as the basis for the regeneration decision algorithm.

[0115] The sensor network includes a fine-monitoring unit for the purification matrix. To achieve independent evaluation of the operating status of each high-temperature current-varying capacitor deionization unit in the dynamic matrix purification module, an independent outlet conductivity sensor is configured at the independent outlet of each of the N high-temperature current-varying capacitor deionization units. The central controller continuously compares the inlet conductivity (i.e., the conductivity of a specific unit) of the inlet of the unit. The instantaneous removal rate of the high-temperature current-ratio capacitor deionization unit is determined by its outlet conductivity and other parameters. When the central controller detects that the outlet conductivity of a certain unit no longer decreases or shows a rebound trend, it determines that the electrode adsorption capacity of that high-temperature current-ratio capacitor deionization unit is saturated, and the regeneration request status flag corresponding to the high-temperature current-ratio capacitor deionization unit is set in its internal logic. Set to 1.

[0116] The sensor network may also include auxiliary status monitoring units. For example, an electromagnetic flowmeter can be installed on the bypass purification loop to provide feedback on the bypass purification flow to the central controller, enabling closed-loop flow control. Pressure sensors can be installed at the inlet and outlet of the main circulating water pump and the bypass booster pump, as well as at the inlet and outlet manifolds of the high-temperature current-changing capacitor deionization dynamic matrix purification module, to monitor the system's pressure status and diagnose potential pipe blockages or leaks. All the signals from these sensors are connected to the corresponding input modules of the central controller via shielded cables.

[0117] The sensing and collaborative control module further includes an actuator network as its execution layer. The actuator network is the means by which the central controller physically intervenes in the operation of the cooling water closed-loop purification and thermal energy cascade utilization system, and it consists of a series of electrically driven devices that receive output commands from the central controller.

[0118] The core component of the actuator network is a purification matrix control execution unit. This unit directly operates on the high-temperature current-variable capacitor deionization dynamic matrix purification module and specifically includes: an automatic isolation valve system. Each high-temperature current-variable capacitor deionization unit in the dynamic matrix purification module has an inlet isolation valve and an outlet isolation valve installed on its inlet and outlet branches. These isolation valves are electrically operated or electro-pneumatically controlled valves, and their electrical actuator control terminals are connected to the digital output module of the central controller. The central controller sends switching signals to the actuators of specific valves to achieve online activation, bypass isolation, and regeneration switching of any high-temperature current-variable capacitor deionization unit. A programmable DC power supply array. Each high-temperature current-variable capacitor deionization unit in the dynamic matrix purification module is powered by an independent, programmable DC power supply module. The control interface of the programmable DC power supply module (e.g., an analog input interface or an RS-485 communication interface) is connected to the analog output module or communication module of the central controller. This connection allows the central controller to independently and precisely apply a specific voltage value and polarity to each high-temperature current-ratio capacitor deionization unit according to the purification or regeneration requirements (e.g., applying a positive voltage of +1.2V during the adsorption phase and a reverse voltage of -1.2V during the regeneration phase).

[0119] The actuator network further includes a hydrodynamic regulating actuator unit. This unit controls the circulation rate and distribution ratio of the fluid within the system, specifically including: variable frequency drives for the main circulating water pump and the bypass booster pump. The frequency setting input of the variable frequency drive is connected to the analog output module of the central controller. The central controller adjusts the output frequency of the variable frequency drive by outputting a continuously changing current or voltage signal, thereby steplessly regulating the speed of the main circulating water pump and the bypass booster pump to achieve precise control of the main loop circulation flow and the bypass purification flow. An electric positioner for the bypass flow regulating valve is also included. The bypass flow regulating valve is a regulating valve with an electric positioner. The electric positioner receives control signals from the analog output module of the central controller and precisely controls the valve opening according to the signal magnitude, serving as a supplement or replacement for the variable frequency speed regulation of the bypass booster pump, achieving fine regulation of the bypass purification flow.

[0120] The actuator network may also include auxiliary regeneration actuators. For example, a miniature solenoid valve connected to the thermally assisted regeneration interface on the high-temperature current-varying capacitor deionization unit has its control coil connected to the digital output module of the central controller. When the regeneration decision algorithm determines that thermally assisted regeneration is required, the central controller can output a pulse signal to momentarily open the miniature solenoid valve, injecting a small amount of cryogenic fluid to enhance the desorption effect.

[0121] The core of intelligence in a sensing and collaborative control module lies in the control logic that runs within it. Control logic is not an abstract concept, but rather is solidified and instantiated into one or more specific control programs that run in the central processing unit module of a central controller (e.g., a programmable logic controller, PLC).

[0122] For overall system state transitions and sequential control, Function Block Diagrams (FBDs) or Sequential Function Charts (SFCs) can be used for programming to clearly represent the transition relationships between different operating conditions (e.g., system startup, normal operation, unit regeneration, and shutdown). For algorithms involving complex mathematical operations and conditional judgments, such as dynamic adjustment algorithms for purification load and regeneration decision algorithms, it is preferable to use Structured Text (ST) language for programming to achieve flexible and precise algorithm logic.

[0123] The control program is downloaded and stored in the program memory of the central controller. The central processing unit module executes the control program in a continuous, cyclical scan cycle. Within each scan cycle, the central controller first performs an input scan, which involves reading the latest data from all sensor networks from the analog and digital input modules and storing it in its internal data registers.

[0124] Subsequently, the central controller executes the program execution phase. During this phase, the program module for the dynamic adjustment algorithm of the purification load is invoked. This central processing unit module reads the real-time conductivity value from its internal data register. And compare it with the target conductivity setting preset in the human-machine interface (HMI). A comparison is made. Based on the comparison results, the dynamic adjustment algorithm for purification load dynamically calculates the optimal number of online purification units required at the current time. The output of this program module is a set of Boolean status flags, each corresponding to the target status (online or offline) of N high-temperature current-varying capacitor deionization units.

[0125] Meanwhile, the program module of the regeneration decision algorithm is also called in parallel or sequentially to poll and check the regeneration request status flag bit of each high-temperature current-varying capacitor deionization unit. (This flag is set by another subroutine responsible for monitoring the unit's outlet conductivity). Once a unit is detected... When set to 1, the program module immediately reads the variable representing the real-time output power of the ORC generator set. The internally defined decision-making logic of the program is: if and only if AND Preset power threshold The condition for ) is met before triggering the action on the first ) The regeneration sequence of each unit.

[0126] At the end of the program execution phase, the central controller generates the final actuator instructions based on the output of the aforementioned algorithm modules and the overall system safety interlock logic. For example, if the dynamic adjustment algorithm for the purification load decides to... If a unit is put into online operation, the central controller will prepare an activation command, pointing to the unit that is online. The unit is associated with the unit inlet isolation valve and the unit outlet isolation valve. If the regeneration decision algorithm decides on the unit... If one unit is regenerated, the central controller will prepare a series of instructions, including shutting down the first unit. The isolation valve of the unit is set with reverse voltage to the first... Independent DC power supply modules for each unit, etc.

[0127] Finally, during the output refresh phase of the scan cycle, the central controller applies all prepared instructions synchronously and in one go to each actuator in the actuator network through the analog and digital output modules. This cycle of reading, processing, and execution repeats continuously at millisecond speeds, thereby achieving continuous, dynamic, and coordinated closed-loop automatic control of the entire system.

[0128] When the graphitization furnace is operating under stable conditions, the system operates efficiently and collaboratively.

[0129] First, high-temperature cooling water at 150°C to 180°C enters the energy cascade coupling utilization module. In the first-stage utilization unit (ORC generator set), its high-grade thermal energy is converted into electrical energy to sustain the system, and the water temperature drops to 110°C to 130°C. Subsequently, the medium-temperature cooling water flows sequentially through the second-stage utilization unit (absorption chiller unit) and the third-stage utilization unit (terminal heat exchanger) for cooling and heating, and finally returns to the main circulation after the water temperature drops to 50°C to 60°C.

[0130] Meanwhile, a small stream of uncooled high-temperature cooling water (150°C to 180°C) is diverted to the bypass high-temperature current-varying capacitor deionization dynamic matrix purification module to improve purification efficiency by utilizing high temperature.

[0131] Under steady state, the real-time conductivity of the main circuit With preset target conductivity The deviation is extremely small. Based on this, the dynamic adjustment algorithm for the purification load within the sensing and collaborative control module calculates the minimum number of online purification units required. (in .

[0132] The controller commands the isolation valves of k high-temperature current-varying capacitor deionization units to open and applies a positive adsorption voltage (e.g., +1.2V) for desalination and purification. The remaining Nk units are in offline standby mode and do not consume power. The purified high-temperature pure water and the low-temperature waste water after energy cascade utilization are combined at the inlet of the main circulating water pump.

[0133] Under this operating condition, there is no unit saturation, and a regeneration request is initiated. When the value is 0, the regeneration decision algorithm is not triggered, and the low-temperature membrane distillation zero-emission module is in standby mode. The system accurately maintains water quality with minimal energy consumption while maximizing the value of waste heat.

[0134] When the water quality in the main circuit deteriorates due to reasons such as minor leaks in the heat exchange equipment, the system will respond automatically.

[0135] An online conductivity sensor deployed at the inlet of the main circulating water pump detected the real-time conductivity. The value rises and exceeds the preset threshold. The dynamic adjustment algorithm for the purification load within the sensing and collaborative control module adjusts based on the increased deviation ( - Recalculate the required optimal number of online purification units. , ( ).

[0136] The controller immediately selects from the offline standby unit. Each reinforcement unit sends opening commands to the inlet and outlet isolation valves of these units via its digital output module. Simultaneously, it sends commands to the independent DC power supply modules of these units via its analog output or communication module to apply a standard positive adsorption voltage. With... The addition of several reinforcement units instantly boosted the total flux and adsorption capacity of the purification module, curbing and reversing the upward trend in conductivity until... Restabilized at the target value The entire process is fully automated, requiring no human intervention and ensuring stable water quality.

[0137] When a high-temperature current-ramp capacitor deionization unit (unit) When the adsorption becomes saturated due to long-term operation, the system executes an intelligent regeneration decision.

[0138] unit The independent conductivity sensor at the outlet detected a decrease in its purification efficiency. The sensing and collaborative control module determined that it was saturated and set the corresponding regeneration request status flag inside. Set to 1.

[0139] The regenerative decision-making algorithm is triggered, but it first assesses the system's energy state. The controller reads the real-time output power of the ORC generator set. In this high-profit scenario (e.g., graphitization furnace operating at full capacity), Power higher than the preset threshold This means that the economic benefits of power generation are higher.

[0140] Therefore, the regeneration decision algorithm decides to postpone regeneration. The controller executes a coordinated action: first, it shuts down the unit via the digital output module. The inlet and outlet isolation valves are used to isolate them offline, but their... The request status is =1. Secondly, to maintain the system's total purification capacity, the purification load dynamic adjustment algorithm responds immediately, activating a healthy unit (such as unit 1) from the standby units. It has been put into online operation.

[0141] Through this strategy, the unit Regeneration is intelligently postponed to a time window when power generation revenue is lower (when... < At the same time, the system's water purification capacity remains unaffected, achieving optimal overall operational efficiency.

[0142] When the system decides to use a saturated cell (cell) When it is regenerated, the only waste liquid stream it produces is treated to achieve zero discharge.

[0143] Sensing and collaborative control module to unit The power module applies a reverse voltage (e.g., -1.2V) to desorb the adsorbed ions, forming a high-temperature, high-concentration concentrate. This waste liquid is then directed to the hot-side inlet of the low-temperature membrane distillation zero-emission module.

[0144] Meanwhile, the lowest-temperature waste water from the end of the energy cascade coupling utilization module is guided as condensate to the cold-side feed inlet of the low-temperature membrane distillation zero-emission module.

[0145] Inside the membrane module, a vapor pressure difference is created between the high-temperature concentrate on the hot side and the low-temperature waste water on the cold side. This pressure difference drives water molecules in the concentrate to pass through the hydrophobic microporous membrane in the form of vapor, condensing into high-purity water on the cold side, while salt ions are completely retained on the hot side.

[0146] The recovered high-purity water is mixed with the cold-side waste water and then fed back into the main cooling circulation loop from the pure water outlet, achieving a closed-loop water resource system. On the hot side, moisture is continuously removed, and salt is concentrated to supersaturation, eventually being collected as salt mud or crystals through the solids discharge interface, thus achieving zero liquid discharge for the entire system.

Claims

1. A closed-loop cooling water purification and thermal energy cascade utilization system, characterized in that, include: An energy cascade coupling utilization module is used to release the heat energy in stages from the high-temperature cooling water discharged from the graphitization furnace. A high-temperature current-changing capacitor deionization dynamic matrix purification module is installed on the bypass purification circuit; the water inlet of the bypass purification circuit is located at the cooling water outlet of the graphitization furnace and before the water inlet of the energy cascade coupling utilization module, for guiding the high-temperature cooling water; the purified water outlet of the high-temperature current-changing capacitor deionization dynamic matrix purification module is connected to the inlet of the main circulating water pump. The low-temperature membrane distillation zero-emission module has its concentrate inlet connected to the regeneration outlet of the high-temperature current-varying capacitor deionization dynamic matrix purification module, the cold-side feed inlet of the regeneration outlet of the high-temperature current-varying capacitor deionization dynamic matrix purification module connected to the end heat energy outlet of the energy cascade coupling utilization module, and the pure water outlet of the high-temperature current-varying capacitor deionization dynamic matrix purification module connected to the inlet of the main circulating water pump. The sensing and collaborative control module establishes electrical or communication connections with the energy cascade coupling utilization module, the high-temperature current-varying capacitor deionization dynamic matrix purification module, and the low-temperature membrane distillation zero-emission module, respectively.

2. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 1, characterized in that, The energy cascade coupling utilization module includes: The primary utilization unit is an organic Rankine cycle generator set used to convert the high-grade thermal energy of the high-temperature cooling water into electrical energy. The secondary utilization unit, located downstream of the primary utilization unit, is an absorption chiller unit used to generate cooling capacity using the medium-temperature cooling water flowing out of the primary utilization unit. The tertiary utilization unit, located downstream of the secondary utilization unit, is a terminal heat exchanger used to recover residual low-grade heat energy in the cooling water. The outlet of the tertiary utilization unit constitutes the terminal heat energy outlet.

3. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 1, characterized in that, The high-temperature current-varying capacitor deionization dynamic matrix purification module includes: Multiple high-temperature current-ramp capacitor deionization units are arranged in parallel; The inlet main pipe and the outlet main pipe are provided, and multiple high-temperature current changing capacitor deionization units are installed between the inlet main pipe and the outlet main pipe. Each high-temperature current changing capacitor deionization unit is equipped with a unit inlet isolation valve and a unit outlet isolation valve. Both the unit inlet isolation valve and the unit outlet isolation valve are connected to the sensing and collaborative control module to enable independent input or isolation of each high-temperature current-varying capacitor deionization unit.

4. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 1, characterized in that, The low-temperature membrane distillation zero-emission module includes: Hydrophobic microporous membrane; A hot-side flow channel is provided on the hot side of the hydrophobic microporous membrane, and the inlet of the hot-side flow channel is connected to the inlet of the low-temperature membrane distillation zero-discharge concentrate. A cold-side flow channel is provided on the cold side of the hydrophobic microporous membrane, with its inlet connected to the cold-side feed port and its outlet connected to the pure water outlet. The solidified material discharge port is located at the end of the hot-side flow channel.

5. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 3, characterized in that, The sensing and collaborative control module is configured as follows: The sensing and collaborative control module has a built-in dynamic adjustment algorithm for purification load. Based on the deviation between the real-time water conductivity measured on the main cooling circulation loop and the preset target conductivity, the algorithm dynamically calculates the number of high-temperature current-varying capacitor deionization units to be put into operation. An opening command is sent to the inlet isolation valve and the outlet isolation valve corresponding to each of the high-temperature current-varying capacitor deionization units.

6. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 1, characterized in that, It also includes energy self-sufficiency connectivity: The energy self-sustaining connection path electrically connects the power output terminal of the energy cascade coupling utilization module to the power receiving terminal of the sensing and collaborative control module and the DC power supply module of the high-temperature current-varying capacitor deionization dynamic matrix purification module.

7. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 1, characterized in that, The sensing and collaborative control module is configured with: The regeneration decision algorithm determines the regeneration command to be executed for the high-temperature current-varying capacitor deionization unit; The regeneration request status of the high-temperature current-varying capacitor deionization unit is acquired in real time. The real-time output power of the energy cascade coupling utilization module is acquired in real time. The logic of the regeneration decision algorithm is that the sensing and cooperative control module sends the regeneration execution command only when the regeneration request status is 1 and the real-time output power is greater than the power threshold.

8. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 7, characterized in that, The sensing and collaborative control module is further configured with: The sensor network includes a dedicated outlet conductivity sensor at the purified water outlet of each high-temperature current-varying capacitor deionization unit. By monitoring the signal from the outlet conductivity sensor, the saturation state of the high-temperature current-varying capacitor deionization unit is determined, and the regeneration request state is generated.

9. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 3, characterized in that, Each of the aforementioned high-temperature current-varying capacitor deionization units includes: An electrode stack consisting of alternating high-temperature resistant porous electrodes and ion-permeable separators, wherein the high-temperature resistant porous electrodes are made of a composite material of graphene and carbon nanotubes. The unit housing is resistant to high temperature and high pressure, and the electrode stack is encapsulated inside the unit housing; the unit housing has a flow-through structure for guiding cooling water vertically through the electrode stack.

10. The cooling water closed-loop purification and thermal energy cascade utilization system according to claim 9, characterized in that, The sensing and collaborative control module is also configured to: According to the working stage of the high-temperature current-ratio capacitor deionization unit, a command is sent to the independent DC power supply module to apply a positive adsorption voltage when the high-temperature current-ratio capacitor deionization unit is in the adsorption stage and to apply a reverse desorption voltage when the high-temperature current-ratio capacitor deionization unit is in the regeneration stage.

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