High-efficiency water-saving and emission-reduction system and method for circulating cooling water in petroleum refining

Abstract

This invention relates to the field of industrial water treatment technology, specifically to a high-efficiency water-saving and emission-reduction system and method for circulating cooling water in petroleum refining processes. The system includes: a circulating cooling water bypass filtration unit for receiving a portion of the high-temperature, easily scale-forming circulating cooling water after heat absorption and filtering out suspended solids; and a circulating cooling water bypass high-efficiency crystallization and softening unit for receiving another portion of the high-temperature, easily scale-forming circulating cooling water after heat absorption. If the water hardness exceeds a preset value, the circulating cooling water undergoes rapid crystallization and softening treatment, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other circulating cooling water is directly subjected to deep filtration to remove hardness. This solution reduces the concentration of scale-forming ions in the circulating cooling water, reduces the concentration of suspended solids and turbidity in the circulating cooling water, and achieves high-efficiency water saving and emission reduction.

Description

Technical Field

[0001] This invention relates to the field of industrial water treatment technology, specifically to a high-efficiency water-saving and emission-reduction system and method for circulating cooling water in petroleum refining. Background Technology

[0002] The petroleum refining industry is a major water consumer, and water consumption per unit product is a key indicator for evaluating the production efficiency of refining enterprises. Water conservation and emission reduction are also important responsibilities for petrochemical companies. Especially with the requirement to gradually phase out inefficient, unstable, and substandard water-related systems, and considering the current situation of production enterprises, it is necessary to increase R&D investment, gradually adopt new technologies and processes, improve wastewater utilization rates, gradually reduce wastewater discharge, and gradually move towards the goal of zero industrial wastewater discharge.

[0003] Currently, water-saving technology research in the field of industrial circulating cooling water conservation in petroleum refining and chemical enterprises mainly focuses on increasing the circulation frequency of circulating cooling water, increasing the concentration ratio, reducing wastewater discharge, reducing fresh water replenishment, and improving the deep treatment and reuse rate of wastewater. In this process, the aspect with the greatest impact on water conservation and emission reduction is increasing the concentration ratio and circulation frequency of the circulating cooling water. However, hastily increasing the concentration ratio of circulating cooling water inevitably leads to the accumulation and precipitation of scaling substances in the circulating cooling water, causing large-scale scaling in the heat exchange system, affecting heat exchange efficiency, and thus threatening the safe and stable operation of refining and chemical production units. Therefore, how to efficiently and cleanly separate scaling substances from the circulating cooling water or achieve a stable operating condition, and prevent scaling in heat exchange units under high concentration ratios, is a water-saving challenge currently faced by most petroleum refining and chemical production enterprises.

[0004] Currently, there are several main processes for addressing the enrichment and precipitation of scale in circulating cooling water: traditional lime softening and hardening treatment, ion exchange softening treatment, and high-efficiency chemical scale inhibition and stabilization processes. Among these, the traditional lime softening + flocculation sedimentation process suffers from drawbacks such as excessively long reaction times, complex unit configurations, large footprint, high cost, large lime dosage, high system failure rate, and the generated sludge being difficult to dispose of properly. Furthermore, this technology offers limited reduction in effluent hardness, cannot efficiently remove scale from the water, and has limited effect on increasing the concentration ratio of circulating cooling water, resulting in high hardness and alkalinity, large wastewater discharge, and still significant scaling risks, with insignificant overall water saving and emission reduction effects. Ion exchange softening treatment, on the other hand, suffers from low processing load, low cycle water production, frequent regeneration, and the generation of acidic regeneration wastewater that cannot be recycled or treated, leading to new high-salinity wastewater and corrosion problems. These methods are gradually being phased out. High-efficiency scale inhibitor treatment is still the process route used by most companies. However, this process involves adding a large amount of chemical agents to the cooling water system daily, but can only control a limited concentration ratio. The system discharge volume is large, the fresh water replenishment volume is large, and the chemical residues in the discharged wastewater have a lot of negative impacts on water pollution and deep reuse. The wastewater treatment cost is high, resource reuse cannot be achieved, the industrial water utilization rate is low, the water consumption of individual products is high, the water resource consumption is large, and the addition of a large amount of chemical substances increases the environmental burden. The cost of the agents is also high, and the overall water saving and emission reduction effect is not obvious. In order to completely eliminate the drawbacks of the existing technology, it is necessary to design a targeted technical solution. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide a highly efficient water-saving and emission-reducing system and method for circulating cooling water in petroleum refining.

[0006] To achieve the above objectives, the first aspect of the present invention provides a high-efficiency water-saving and emission-reduction system for circulating cooling water in petroleum refining processes, characterized in that it comprises:

[0007] The circulating cooling water side-filter unit is used to receive a portion of the high-temperature, easily scale-forming circulating cooling water after heat absorption, and to filter out suspended solids in the water.

[0008] The circulating cooling water bypass high-efficiency crystallization and softening unit is used to receive another part of the high-temperature, easily scaled circulating cooling water after heat absorption. If the water hardness exceeds the preset value, the circulating cooling water is subjected to rapid crystallization and softening treatment, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other circulating cooling water is directly subjected to deep filtration to remove hardness.

[0009] A circulating water return water residual pressure bypass water supply unit is adopted, which is connected to the circulating cooling water bypass filter unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit respectively. It is used to use the circulating cooling water return water residual pressure as the power source to send the high-temperature and easily scaled circulating cooling water into the circulating cooling water bypass filter unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit respectively.

[0010] The big data intelligent control unit is electrically connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit, respectively. It is used to monitor and judge the water quality indicators in the system in real time, feed back the water hardness to the circulating cooling water bypass high-efficiency crystallization hardening and softening unit, and control the inlet and outlet water processes of the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit.

[0011] A second aspect of this invention provides a highly efficient water-saving and emission-reduction method for circulating cooling water in petroleum refining processes, comprising the following methods:

[0012] The high-temperature, scale-prone circulating cooling water after heat absorption is divided into two streams. One stream is filtered to remove suspended solids. The other stream is tested for water hardness. If the water hardness exceeds a preset value, the other stream of circulating cooling water is subjected to rapid crystallization to remove hardness and soften it, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other stream of circulating cooling water is directly subjected to deep filtration to remove hardness.

[0013] The circulating cooling water after the two processes is reused for circulating cooling.

[0014] The technical solution of this invention has the following beneficial effects: 1. The process device designed in this invention has a simple process flow, modular design, high processing efficiency, high degree of automation, small footprint, small amount of civil engineering, and strong replicability of the complete process package. It can reduce the amount of wastewater discharged and production water consumption of refining and chemical enterprises as a whole, realize water conservation and efficiency improvement of the entire refining and chemical industry, and has broad application prospects; 2. The process device designed in this invention belongs to the "recovery method" process route, which can completely replace the traditional "disposal method" process route, ultimately achieving water conservation and emission reduction, energy conservation and consumption reduction, and helping petroleum refining and chemical enterprises to fulfill their "green enterprise" goals and social responsibilities; 3. The complete set of water-saving and emission-reduction devices designed in this invention combines self-induced chemical crystallization reaction and pellet physical fluidization reaction, with high flow rate, high decalcification rate, good dehardening effect, low effluent hardness, low effluent turbidity, and strong operational stability. The effluent exhibits minimal turbidity fluctuations and high quality. Furthermore, the intelligent big data management system automatically adjusts the effluent hardness in real-time according to the operating conditions of the main refining and chemical production unit, effectively ensuring the safe, efficient, and economical operation of the refining and chemical production system. Simultaneously, it significantly increases the concentration ratio of the circulating cooling water system, achieving water conservation and emission reduction, improving the utilization rate of industrial wastewater, and reducing the amount of water entering the subsequent high-salinity deep treatment system, thus significantly lowering the operating costs of high-salinity deep treatment and reuse. 4. The process device designed in this invention produces simple byproducts. The only byproduct is 2-3mm calcium carbonate particles with high purity (over 92%), essentially water-free, and can be completely reused in the enterprise's boiler desulfurization section. This achieves resource recovery and reuse of byproducts, realizing a circular economy. The "recycling method" process route of this invention is far superior to the traditional "disposal method" process route. Moreover, there is no other wastewater or waste discharge, completely solving the drawbacks of traditional processes, resulting in higher operating efficiency, lower operating costs, and a more environmentally friendly approach. Attached Figure Description

[0015] Figure 1 This is a simplified diagram of a high-efficiency water-saving and emission-reduction device for a circulating cooling water system in petroleum refining.

[0016] Figure 1 In the middle: Mechanical ventilation cooling tower-1, circulating cooling water forebay-2, circulating cooling water pump-3, refining and chemical heat exchange unit-4, mechanical ventilation fan-5, circulating cooling water side filter unit-6, crystallization hardening and softening equipment-7, hardening removal side filter equipment-8, wastewater discharge pool-9, high salinity treatment unit-10, thermal power boiler desulfurization section-11, chemical dosing room-12. Detailed Implementation

[0017] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0018] The first aspect of this invention provides a high-efficiency water-saving and emission-reduction system for circulating cooling water in petroleum refining processes, comprising:

[0019] The circulating cooling water side-filter unit is used to receive a portion of the high-temperature, easily scale-forming circulating cooling water after heat absorption, and to filter out suspended solids in the water.

[0020] The circulating cooling water bypass high-efficiency crystallization and softening unit is used to receive another part of the high-temperature, easily scaled circulating cooling water after heat absorption. If the water hardness exceeds the preset value, the circulating cooling water is subjected to rapid crystallization and softening treatment, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other circulating cooling water is directly subjected to deep filtration to remove hardness.

[0021] A circulating water return water residual pressure bypass water supply unit is adopted, which is connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit respectively. It is used to use the residual pressure of the circulating cooling water return water as the power source to send the high-temperature and easily scaled circulating cooling water into the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit respectively. The circulating water return water residual pressure bypass water supply unit includes a bypass water receiving pipe installed in the circulating cooling water return water pipe and detection instruments and control valves installed on the bypass water receiving pipe.

[0022] The big data intelligent control unit is electrically connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit, respectively. It is used to monitor and judge the water quality indicators in the system in real time, feed back the water hardness to the circulating cooling water bypass high-efficiency crystallization hardening and softening unit, and control the inlet and outlet water processes of the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit.

[0023] The circulating cooling water side-stream filtration unit includes a crystallization and softening device and a post-softening side-stream filtration device, which are connected by pipelines.

[0024] The crystallization hardening and softening equipment is used to rapidly crystallize and soften circulating cooling water. The treated circulating cooling water flows into the post-hardening side-stream filtration equipment through a pipeline. The post-hardening side-stream filtration equipment is used for deep filtration and hardening removal.

[0025] The circulating cooling water return pressure bypass water supply unit is constructed by installing bypass water inlets, monitoring instruments, and control valves in the circulating cooling water return pipeline. It utilizes the residual pressure of the circulating cooling water return as the power source for the hardening and softening unit and the filtration unit, replacing the traditional design of the water supply network and pumps. This achieves low-cost operation and simplified control of the system. These units and modules together form a water-saving and emission-reduction device for circulating cooling water in petroleum refining. Through step-by-step reaction and state control, it removes different scale substances and turbidity, achieving softening and turbidity reduction of the circulating cooling water, while simultaneously enabling the resource recycling of by-products.

[0026] Furthermore, the circulating cooling water bypass filtration unit also includes a circulating cooling water bypass water inlet module, a crystal nucleus selection and addition module, an automatic dosing control module, a self-induced crystallization granulation hardening and softening module, a monitoring and automatic control module, a particle emission collection and by-product comprehensive utilization module, an automatic water inlet module, and a non-powered self-filtration and self-backwashing module.

[0027] The automatic water inlet module is used to send the high-temperature, easily scale-forming circulating cooling water after heat absorption into the circulating cooling water side filter unit.

[0028] The non-powered self-filtration and self-backwashing module is used for deep filtration and turbidity reduction of the effluent after high-efficiency hardening and softening, reducing suspended solids content, and realizing automatic backwashing and regeneration to restore filtration function. It is located at the rear of the high-efficiency hardening reactor and is connected in series with the high-efficiency hardening reactor through the effluent pipeline.

[0029] The circulating cooling water bypass water inlet module is used to send the high-temperature, easily scaled circulating cooling water after heat absorption into the crystallization hardening and softening equipment or the hardening removal bypass filtration equipment.

[0030] The crystal nucleus selection and addition module is used to uniformly and stably add the selected special induced crystal nuclei to the crystallization separation zone of the high-efficiency hardening reactor, and is located on the side of the main unit of the high-efficiency hardening reactor. It includes a high-efficiency hardening reactor and a crystal nucleus adder. The high-efficiency hardening reactor directly draws water to the crystal nucleus adder through a top outlet pipe. The top outlet pipe is equipped with an online electromagnetic flow meter and an electric regulating valve to monitor and adjust the fluidized water flow of the crystal nucleus adder in real time.

[0031] The automatic dosing control module is used to uniformly and continuously add the liquid alkali or soda ash required for the induced crystallization reaction to the crystallization reaction zone of the high-efficiency hardness removal reactor. It can also automatically adjust the dosing amount based on the influent and effluent indicators collected by the detection and control module, achieving precise dosing. It is located in the auxiliary equipment position of the high-efficiency hardness removal reactor, with the dosing point located in the main reaction zone above the water distribution area. The self-induced crystallization granulation hardness removal and softening module is used for crystallization granulation and hardness removal, and is located in the center of the hardness removal and softening workshop or the skid-mounted integrated platform.

[0032] The monitoring and automatic control module is used for online monitoring of the influent and effluent water quality of the system. After logical analysis of the collected data by the big data intelligent management and control unit, the automatic control module issues instructions to other modules to achieve automatic regulation of the influent flow rate and chemical dosage, thus realizing automatic regulation and operation of the system. It is installed on the influent and effluent pipelines of the hardening and softening device and in the local control cabinet.

[0033] The particle emission collection and by-product comprehensive utilization module is connected to the crystallization hardening and softening equipment and is used to recycle by-product calcium carbonate particles. It includes an automatic particle emission pipeline, a self-flushing pipeline, and a self-separation and collection box to realize automatic by-product transportation and resource recycling.

[0034] The self-induced crystallization granulation hardening and softening module utilizes a superior crystallization induction material. This material possesses strong physical and chemical stability, and its hardness and density are suitable for the conditions required for both the chemical and physical reactions involved in crystallization granulation and hardening removal. The module features stepwise reactions, internal fluidized circulation, and a controllable and adjustable operation mode. The optimal addition of crystal nuclei involves directly drawing water from the top effluent pipe of the existing high-efficiency hardening reactor to the crystal nuclei addition system. An online electromagnetic flowmeter and electric regulating valve are designed on the water inlet pipe to monitor and adjust the fluidized water flow of the crystal nuclei addition system in real time. Big data intelligent management and control utilizes an automatic intelligent monitoring platform. During the operation of the entire unit, relevant parameters are automatically collected, enabling intelligent process monitoring, ensuring stable system operation, and guaranteeing that process indicators meet requirements.

[0035] Furthermore, the big data intelligent control unit is used to automatically and continuously monitor the influent and effluent water quality indicators of the hardening and softening equipment, and to coordinate with the automatic dosing control module to dosing, thereby controlling the production water quality to meet the standards in real time; and to automatically and continuously monitor the effluent water quality of the circulating cooling water side-filtration unit to ensure the stability of the recycled water quality.

[0036] Furthermore, the system also includes a cooling tower, a circulating cooling water forebay, and a heat exchange unit.

[0037] The cooling tower is used to perform the functions of heat dissipation, cooling and collection of circulating cooling water;

[0038] The heat dissipation and cooling collection of the circulating cooling water is connected to the cooling tower and the heat exchange unit pipeline respectively. It is used to collect the circulating cooling water after it has been cooled by the cooling tower, and to perform descaling and sterilization treatment before sending the circulating cooling water into the heat exchange unit.

[0039] The heat exchange unit is connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization de-hardening and softening unit, respectively, and is used to transport high-temperature circulating cooling water that is prone to scaling after heat absorption.

[0040] The process flow of the high-efficiency water-saving and emission-reduction system for circulating cooling water in petroleum refining is as follows: Figure 1As shown, the mechanical ventilation cooling tower 1 of the refining and chemical industry enterprise undertakes the functions of heat dissipation, cooling and collection of circulating cooling water during normal operation. After ventilation and heat dissipation, the circulating cooling water first collects in the circulating cooling water forepool 2. A certain amount of slow-release scale inhibitor and bactericide are added through the chemical dosing room 12. After mixing, the circulating cooling water is pumped out by the circulating cooling water pump 3 and pumped into the heat exchange unit 4 of the petroleum refining and chemical production system to exchange heat and cool down the refining and chemical production equipment and production product medium. The circulating cooling water has a high temperature after absorbing heat. Through the residual pressure of the pipeline network, it returns to the mechanical ventilation cooling tower 1. After forced ventilation and heat exchange and cooling by the mechanical ventilation fan 5, it flows back to the bottom of the mechanical ventilation cooling tower 1, and so on. To achieve the goal of efficiently removing scale and suspended solids from the circulating cooling water, the high-temperature, easily scale-forming circulating cooling water discharged from the refining and chemical heat exchange unit 4 is introduced into the circulating cooling water bypass filtration unit 6 through the return water bypass pipeline for filtering suspended solids and other impurities. Simultaneously, a portion of the return water is diverted into the high-efficiency crystallization and softening equipment 7 via a return water residual pressure diversion device. Under the dual action of chemical crystallization and physical fluidization, scale-forming substances in the bypass circulating cooling water are rapidly and efficiently physically separated, resulting in a significant reduction in the total hardness and alkalinity of the effluent. The softened effluent then uses residual pressure to enter the dedicated hardness-removing bypass filtration equipment 8 for deep filtration and turbidity reduction treatment. Finally, high-quality water with low hardness, low alkalinity, and low turbidity is replenished into the circulating cooling water forepool 2, mixed with the cooling tower water, and then pumped again by the circulating cooling water pump 3 into the refining and chemical heat exchange unit. In heat exchange unit 4, the water undergoes heat exchange and cooling. Due to the high quality of the effluent after bypass hardening, softening, and high-efficiency filtration, the concentration of scaling substances is significantly reduced. The quality of the circulating cooling water entering the refining heat exchange unit is high, which greatly reduces the scaling rate and risk in the heat exchange unit. The amount of sewage discharged from the circulating cooling water system is significantly reduced, the system concentration ratio gradually increases, and the amount of fresh water replenishment is significantly reduced, achieving water saving and emission reduction effects. At the same time, due to the good water quality of the system, the amount of high-salt wastewater entering the sewage tank 9 from the circulating cooling system is significantly reduced, which in turn significantly reduces the amount of high-salt wastewater entering the subsequent high-salt wastewater deep treatment unit 10. The load of the high-salt water deep treatment unit 10 is reduced, and the overall operating cost is significantly reduced. Meanwhile, the by-product calcium carbonate particles of this process unit are directly transported to the desulfurization section 11 of the thermal power boiler for comprehensive utilization of by-products, realizing a circular economy.

[0041] By physically extracting and separating scale-forming substances from circulating cooling water, the concentration of scale ions in the circulating cooling water is reduced, as are the concentration of suspended solids and turbidity. This completely solves numerous problems in petroleum refining circulating cooling water systems, such as low concentration ratio, large system discharge volume, large chemical reagent dosage, difficulty in treating circulating cooling water discharge, high turbidity of softened effluent, difficulty in reuse, high operating costs of deep wastewater treatment, inability to achieve resource recycling, low industrial water utilization rate, and large water consumption, thus achieving efficient water conservation and emission reduction.

[0042] Based on the same inventive concept, a second aspect of this invention proposes a highly efficient water-saving and emission-reduction method for circulating cooling water in petroleum refining processes, comprising the following methods:

[0043] The high-temperature, scale-prone circulating cooling water after heat absorption is divided into two streams. One stream is filtered to remove suspended solids. The other stream is tested for water hardness. If the water hardness exceeds a preset value, the other stream of circulating cooling water is subjected to rapid crystallization to remove hardness and soften it, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other stream of circulating cooling water is directly subjected to deep filtration to remove hardness.

[0044] The circulating cooling water after the two processes is reused for circulating cooling.

[0045] The carbonate byproducts obtained from the rapid crystallization and softening treatment of the other circulating cooling water are recycled.

[0046] In summary, the technical solution of this invention has the following advantages: 1. The process device designed in this invention has a simple flow, modular design, high processing efficiency, high degree of automation, small footprint, small amount of civil engineering, and strong replicability of the complete process package. It can reduce the wastewater discharge and production water consumption of refining and chemical enterprises as a whole, realize water conservation and efficiency improvement in the entire refining and chemical industry, and has broad application prospects; 2. The process device designed in this invention belongs to the "recovery method" process route, which can completely replace the traditional "disposal method" process route, ultimately achieving water conservation and emission reduction, energy conservation and consumption reduction, and helping petroleum refining and chemical enterprises to fulfill their "green enterprise" goals and social responsibilities; 3. The complete set of water-saving and emission-reduction devices designed in this invention combines self-induced chemical crystallization reaction and pellet physical fluidization reaction, with high flow rate, high decalcification rate, good dehardening effect, low effluent hardness, low effluent turbidity, and strong operational stability. The effluent exhibits minimal turbidity fluctuations and high quality. Furthermore, the intelligent big data management system automatically adjusts the effluent hardness based on the operating conditions of the main refining and chemical production unit, effectively ensuring the safe, efficient, and economical operation of the refining and chemical production system. Simultaneously, it significantly increases the concentration ratio of the circulating cooling water system, achieving water conservation and emission reduction, improving the utilization rate of industrial wastewater, and reducing the amount of water entering the subsequent high-salinity deep treatment system, thus significantly lowering the operating costs of high-salinity deep treatment and reuse. 4. The process device designed in this invention produces simple byproducts. The only byproduct is 2-3mm calcium carbonate particles with high purity (over 92%), essentially water-free, and can be completely reused in the enterprise's boiler desulfurization section. This achieves resource recovery and reuse of byproducts, realizing a circular economy. The "recycling method" process route of this invention is far superior to the traditional "disposal method" process route. Moreover, there is no other wastewater or waste discharge, completely solving the drawbacks of traditional processes, resulting in higher operating efficiency, lower operating costs, and a more environmentally friendly approach.

[0047] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A high-efficiency water-saving and emission-reduction system for circulating cooling water in petroleum refining, characterized in that, include: The circulating cooling water bypass filtration unit is used to receive a portion of the heat-absorbing, high-temperature, easily scale-forming circulating cooling water and filter it to remove suspended solids. The circulating cooling water bypass filtration unit also includes a circulating cooling water bypass water inlet module, a crystal nucleus selection and addition module, an automatic dosing control module, a self-induced crystallization granulation hardening and softening module, a monitoring and automatic control module, a particle emission collection and by-product comprehensive utilization module, an automatic water inlet module, and a non-powered self-filtration and self-backwashing module. The circulating cooling water bypass water inlet module is used to send the heat-absorbing, high-temperature, easily scale-forming circulating cooling water into the crystallization hardening and softening module. The equipment or a side-by-side filtration device after hardening removal; the crystal nucleus selection and addition module is used to uniformly and stably add the screened induced crystal nuclei to the crystallization separation zone of the high-efficiency hardening reactor, and is located on the side of the main body of the high-efficiency hardening reactor; the crystal nucleus selection and addition module includes the high-efficiency hardening reactor and the crystal nucleus dosing device, the high-efficiency hardening reactor directly draws water to the crystal nucleus dosing device through a top outlet pipe, and the top outlet pipe is equipped with an online electromagnetic flow meter and an electric regulating valve to monitor and adjust the fluidized water volume of the crystal nucleus dosing device in real time; the automatic dosing control module is used to add the required amount of chemical dosing for the induced crystallization reaction. Liquid alkali or soda ash is uniformly and continuously added to the crystallization reaction zone of the high-efficiency hardening reactor. The dosage can be automatically adjusted based on influent and effluent indicators collected by the detection and control module, achieving precise dosing. The automatic dosing control module is located in the auxiliary equipment position of the high-efficiency hardening reactor, and the dosing point is located in the main reaction zone above the water distribution area of ​​the reactor. The self-induced crystallization granulation hardening and softening module is used for crystallization granulation and hardening removal, and is located in the center of the hardening and softening workshop or a skid-mounted integrated platform. The monitoring and control module is used for online monitoring of the influent and effluent water quality of the system. The system automatically controls the collected data through a big data intelligent management and control unit, and then issues instructions to other modules to achieve automatic regulation of the influent flow rate and chemical dosage, thus enabling automatic system operation. The monitoring and automatic control module is located on the inlet and outlet water pipelines of the hardening and softening device and in the local control cabinet. The particle emission collection and by-product comprehensive utilization module is connected to the crystallization hardening and softening equipment and is used to recover and utilize the by-product calcium carbonate particles. The automatic water inlet module is used to send the heat-absorbing, high-temperature, easily scale-forming circulating cooling water into the circulating cooling water side-filter unit. The non-powered self-filtration and self-backwashing module is used for deep filtration and turbidity reduction of the effluent after high-efficiency hardening and softening, reducing the suspended solids content, and realizing its automatic backwashing and regeneration to restore filtration function; the non-powered self-filtration and self-backwashing module is located at the rear of the high-efficiency hardening reactor and is connected in series with the high-efficiency hardening reactor through the effluent pipeline. The circulating cooling water bypass high-efficiency crystallization and softening unit is used to receive another part of the high-temperature, easily scaled circulating cooling water after heat absorption. If the water hardness exceeds the preset value, the circulating cooling water is subjected to rapid crystallization and softening treatment, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other circulating cooling water is directly subjected to deep filtration to remove hardness. It includes a crystallization and softening device and a post-softening filtration device, which are connected by pipelines. The crystallization and softening device is used to perform rapid crystallization and softening treatment on the circulating cooling water. The treated circulating cooling water flows into the post-softening filtration device through the pipeline. The post-softening filtration device is used for deep filtration to reduce turbidity and remove hardness. A circulating water return water residual pressure bypass water supply unit is adopted, which is connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit respectively. It is used to use the residual pressure of the circulating cooling water return water as the power source to send the high-temperature and easily scaled circulating cooling water into the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit respectively. The circulating water return water residual pressure bypass water supply unit includes a bypass water receiving pipe installed in the circulating cooling water return water pipe and detection instruments and control valves installed on the bypass water receiving pipe. The big data intelligent control unit is electrically connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit, respectively. It is used to monitor and judge the water quality indicators in the system in real time, feed back the water hardness to the circulating cooling water bypass high-efficiency crystallization hardening and softening unit, and control the inlet and outlet water processes of the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization hardening and softening unit.

2. The system according to claim 1, characterized in that, The particle emission collection and by-product comprehensive utilization module includes an automatic particle emission pipeline, a self-flushing pipeline, and a self-separating and collection box, which are used to realize the automatic transportation and resource recycling of by-products.

3. The system according to claim 1, characterized in that, The big data intelligent management and control unit is used to automatically and continuously monitor the influent and effluent water quality indicators of the hardening and softening equipment, and to coordinate with the automatic dosing control module to dosing chemicals and control the production water quality to meet the standards in real time; and to automatically and continuously monitor the effluent water quality of the circulating cooling water side filter unit to ensure the stability of the recycled water quality.

4. The system according to any one of claims 1-3, characterized in that, The system also includes a cooling tower, a circulating cooling water forebay, and a heat exchange unit. The cooling tower is used to perform the functions of heat dissipation, cooling and collection of circulating cooling water; The circulating cooling water forebay is connected to the cooling tower and the heat exchange unit pipelines respectively. It is used to collect the circulating cooling water after it has been cooled by the cooling tower, and to perform descaling and sterilization treatment before sending the circulating cooling water into the heat exchange unit. The heat exchange unit is connected to the circulating cooling water bypass filtration unit and the circulating cooling water bypass high-efficiency crystallization de-hardening and softening unit, respectively, and is used to transport high-temperature circulating cooling water that is prone to scaling after heat absorption.

5. A method for efficient water saving and emission reduction of circulating cooling water in petroleum refining, characterized in that, The method is implemented based on the system described in any one of claims 1-4, and includes the following methods: The high-temperature, scale-prone circulating cooling water after heat absorption is divided into two streams. One stream is filtered to remove suspended solids. The other stream is tested for water hardness. If the water hardness exceeds a preset value, the other stream of circulating cooling water is subjected to rapid crystallization to remove hardness and soften it, followed by deep filtration to remove hardness. If the water hardness does not exceed the preset value, the other stream of circulating cooling water is directly subjected to deep filtration to remove hardness. The circulating cooling water after the two processes is reused for circulating cooling.

6. The method for efficient water saving and emission reduction of circulating cooling water in petroleum refining according to claim 5, characterized in that, The carbonate byproduct obtained from the rapid crystallization and softening treatment of the other circulating cooling water is recycled.

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