Desalted water system collaborative optimization method and device and application

Abstract

The invention provides a collaborative optimization method and device for a desalted water system and application, and belongs to the technical field of water treatment.According to the method, in the technological process of desalted water, through the synergistic effect of waste heat recovery, intelligent backwashing control, an efficient desalting process and resource recycling, system energy consumption is reduced, the water recovery rate is increased, and the energy consumption is reduced. Wastewater discharge is reduced, and even wastewater zero discharge is achieved. A grey water raw water heat exchanger is arranged at the upstream of the raw water tank, grey water is subjected to heat exchange and cooling through the grey water raw water heat exchanger, and fresh raw water is communicated with the raw water tank after being subjected to heat exchange and temperature rise through the grey water raw water heat exchanger; the raw water tank is connected with the ultrafilter, the downstream of the ultrafilter is connected with the fiber filter, and the fiber filter is connected with the efficient cation bed; the efficient cation bed is connected with a decarburizer which is connected with a middle water tank; the middle water tank is connected with a high-efficiency anion bed which is connected with a mixed bed; the mixed bed is connected with a desalted water tank. The invention solves the problems of high energy consumption, high water consumption and difficulty in wastewater treatment in the traditional process. Zero discharge of wastewater is realized, and the purity of the prepared pure water is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and specifically to a method and device for collaborative optimization of a desalted water system and its uses. Background Art

[0002] Generally, traditional desalted water systems have problems such as long process flows, complex equipment, high energy consumption, low water recovery rate (45%), and high wastewater treatment costs.

[0003] Existing process technologies have problems such as easy fouling of reverse osmosis membranes, frequent resin regeneration, and un-recovered waste heat, resulting in high operating costs.

[0004] The design process of the desalted water system is long, there are many electrical equipment, high energy consumption, and high equipment maintenance costs; the total system recovery rate is low, the consumption of raw water is large, and there is a lot of wastewater; the amount of once-through water mixed with the discharged wastewater is large, causing a large waste of water resources. Summary of the Invention

[0005] The technical task of the present invention is to solve the deficiencies of the existing technology and provide a method and device for collaborative optimization of a desalted water system.

[0006] The technical solution of the present invention is implemented as follows. A method and use for collaborative optimization of a desalted water system of the present invention. In the process flow of desalted water, through the synergistic effects of waste heat recovery, intelligent backwashing control, high-efficiency desalination process, and resource recycling, the system energy consumption is reduced, the water recovery rate is increased, and wastewater discharge is reduced or even zero wastewater discharge is achieved.

[0007] The process of the desalted water system is as follows: An ash water raw water heat exchanger is provided upstream of the raw water tank. The ash water is cooled by heat exchange in the ash water raw water heat exchanger, and the fresh raw water is heated by heat exchange in the ash water raw water heat exchanger and then connected to the raw water tank. The raw water tank is connected to an ultrafilter. The water path downstream of the ultrafilter is connected to the top of a fiber filter, and the water path at the bottom of the fiber filter is connected to the bottom of a high-efficiency cation bed. After cation exchange, the water path at the top of the high-efficiency cation bed is connected to a decarbonator, and the bottom of the decarbonator is connected to an intermediate water tank. The intermediate water tank is connected to the bottom of a high-efficiency anion bed through a process pump. After anion exchange, the water path at the top of the high-efficiency anion bed is connected to the top of a mixed bed. The water path at the bottom of the mixed bed is connected to a desalted water tank.

[0008] A backwashing water path is also provided between the raw water tank and the ultrafilter.

[0009] A backwashing water path is provided between the top of the mixed bed and the ultrafilter.

[0010] In the desalination system, Differential pressure sensor, PLC controller, backwash inlet valve, backwash pump, drain valve, Timer, equipped with periodic triggering backwash pump; the backwash pump is connected to a spare drain valve; A flow sensor is arranged on the backwash pipeline of the backwash pump, and the flow sensor is equipped with an alarm module.

[0011] The flow sensors installed on the pipelines are all connected to the DCS control system. The DCS control system automatically adjusts the flow solenoid valves of the monitored process pipelines through decentralized control and centralized management.

[0012] The raw water is heated to 25°C by the plate heat exchanger using the waste heat of the grey water and then enters the raw water tank, ultrafilter and fiber filter; The high-efficiency cation bed and high-efficiency anion bed are connected in series downstream for desalination, and the pH is adjusted by adding alkali to the influent through secondary reverse osmosis, and the final produced water is refined by a mixed bed; The ultrafilter backwash cycle is dynamically adjusted by the intelligent backwash control system, and the backwash water is recycled to the raw water tank; The regeneration wastewater generated by the mixed bed and the drainage from the neutralization pool are sent back to the ultrafilter backwash system through the recovery pump; The system operation data is monitored in real time, and the linkage control of waste heat recovery, backwash frequency and pH value is achieved through PLC.

[0013] This method reduces system energy consumption, improves water recovery rate, and achieves zero wastewater discharge through the synergistic effect of waste heat recovery, intelligent backwash control system control, anion bed, cation bed, and mixed bed high-efficiency desalination technology, and resource recycling; The waste heat recovery uses the waste heat of gasified ash water and the plate heat exchanger to heat the raw water so that the raw water temperature is stably controlled at 25±2℃; The intelligent backwash control system dynamically adjusts the ultrafiltration backwash cycle and combines closed-loop recovery of backwash water.

[0014] A device for realizing collaborative optimization of a desalted water system, the system device comprising: A grey water and raw water heat exchanger is arranged upstream of the raw water tank. The grey water is cooled by heat exchange in the grey water and raw water heat exchanger, and the fresh raw water is heated by heat exchange in the grey water and raw water heat exchanger and then connected to the raw water tank. The raw water tank is connected to the ultrafilter. The water channel downstream of the ultrafilter is connected to the top of the fiber filter, and the water channel at the bottom of the fiber filter is connected to the bottom of the high-efficiency cationic bed; After cation exchange, the water channel at the top of the high-efficiency cation bed is connected to the decarbonizer, and the bottom of the decarbonizer is connected to the intermediate water tank; The intermediate water tank is connected to the bottom end of the high-efficiency anion bed through a process pump. After anion exchange, the water path at the top end of the high-efficiency anion bed is connected to the top end of the mixed bed. The water path at the bottom end of the mixed bed is connected to the demineralized water tank. A backwash water path is also provided between the raw water tank and the ultrafilter. A backwash water path is provided from the top end of the mixed bed to the ultrafilter. The pipeline process configuration of the raw water is as follows: Raw water tank → Fiber filter → High-efficiency cation bed → Decarbonator + Intermediate water tank → High-efficiency anion bed → Mixed bed → Demineralized water tank.

[0015] Application of the described collaborative optimization method for a demineralized water system in the water treatment process.

[0016] The beneficial effects of the present invention compared with the prior art are as follows: A collaborative optimization method, device and use for a demineralized water system according to the present invention, through the integration of waste heat recovery, intelligent backwash control, high-efficiency desalination technology and resource recycling, realizes the comprehensive goals of reducing system energy consumption, improving recovery rate and achieving zero wastewater discharge.

[0017] Through the integrated design of waste heat recovery, intelligent backwashing, high-efficiency desalination and resource recycling, the problems of high energy consumption, large water consumption and difficult wastewater treatment in the traditional process are solved. After transformation, the water recovery rate of the system is increased to 70%, the annual operation cost is reduced by 3.748 million yuan, and zero wastewater discharge is achieved, with significant economic and environmental benefits.

[0018] The synergistic effect of waste heat recovery and high-efficiency desalination, and the linkage mechanism of intelligent control and resource closed-loop.

[0019] A cation bed and an anion bed are configured upstream of the mixed bed, which can effectively exert the advantages of the mixed bed. The advantages of the mixed bed are: excellent and stable effluent water quality; less influence on the effluent water quality during intermittent operation; obvious exchange end point, which is conducive to supervision and automatic control; fewer equipment than the double bed, and centralized layout.

[0020] Since the chloride ions and hydroxide ions entering the water after mixed ion exchange immediately form water molecules with very low ionization degree, during the exchange process of the mixed bed resin, due to being in a uniformly mixed state, arranged alternately and in contact with each other, it can be regarded as a multi-stage double-bed pure water machine composed of many anion and cation exchange resins, which can be equivalent to a 1000 - 2000-stage double bed. Because of the uniform mixing, the anion and cation exchange reactions are almost simultaneous, and the generated H + , OH - Immediately synthesize H2O, and the exchange reaction proceeds very thoroughly. Therefore, the effluent water quality of the anion-cation mixed bed pure water equipment is better than that which can be achieved by multiple series-connected double-bed pure water machines, and can produce pure water with a relatively high purity.

[0021] A method and device for collaborative optimization of a desalted water system and its application according to the present invention are reasonably designed, simple in structure, safe and reliable, convenient to use, and easy to maintain, and have good popularization and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Appendix Figure 1 is the process optimization flow chart of the system of the present invention (showing waste heat recovery, high-efficiency desalination and water circulation path); Appendix Figure 2 is the schematic diagram of the intelligent backwashing control logic of the present invention (backwashing cycle and recycled water linkage mechanism); Appendix Figure 3 is the schematic diagram of the waste heat recovery unit and temperature control module of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following is a detailed description of a method and device for collaborative optimization of a desalted water system and its application according to the present invention with reference to the accompanying drawings.

[0024] As shown in the accompanying drawings, a method and device for collaborative optimization of a desalted water system and its application according to the present invention solve the defects of scattered improvement of the existing system through the following collaborative optimization measures: (1) Waste heat recovery and temperature collaborative control module: Heat the raw water to 25°C by using the waste heat of the gasification external discharged ash water through an anti-scaling plate heat exchanger unit, improve the reverse osmosis water production rate (more than 10%), and at the same time stop using the original gasification ash water cooler to reduce the circulating water consumption (500 m³ / h) and cleaning frequency.

[0025] (2) Intelligent backwashing and resource recycling module: Dynamically adjust the ultrafiltration backwashing cycle (40 → 45 minutes), combine the backwashing water to be recycled to the raw water system, reduce the backwashing frequency (24 times / day) and water consumption (20 m³ / h); The mixed bed regeneration waste water, the normal washing / backwashing water are recycled in a closed loop to the ultrafiltration backwashing water tank to realize the recycling of water resources.

[0026] (3) High-efficiency desalination collaborative process: Adopt "fiber filter + double-chamber cation bed + decarbonator + double-chamber anion bed + mixed bed" to replace part of the membrane process, combine with dynamic pH adjustment (pH of the secondary reverse osmosis inlet water = 8.2) to reduce the conductivity (≤0.2 μS / cm), extend the mixed bed regeneration cycle to 21 days, and reduce the discharge of concentrated water (directly enter the intermediate water crystallization system).

[0027] (4) Equipment optimization and energy consumption control module: Stop using redundant raw water pumps (6 units), saving 973,000 yuan in electricity annually; The stirrer of the neutralization water tank operates intelligently intermittently (24 h → 4 h), saving 69,000 yuan in electricity annually.

[0028] Collaborative technology: (1)System integration advantages: The combination of waste heat recovery and high - efficiency desalination technology solves the problems of reduced water production rate and membrane fouling caused by low temperature; Intelligent backwashing and closed - loop water recovery reduce water consumption and at the same time reduce the wastewater treatment load.

[0029] (2)Economic improvement: The annual operating cost is reduced from 14.64 million yuan to 11.39 million yuan, saving 3.748 million yuan; The water recovery rate is increased from 45% to 70%, achieving zero wastewater discharge.

[0030] (3)Environmental benefits: The pH of the regenerated waste liquid is 8, meeting environmental protection standards; Reducing the use of chemicals and the COD load of the discharged wastewater.

[0031] In the present invention: The high - efficiency cation exchanger bed, also known as the high - efficiency cation exchanger.

[0032] The high - efficiency anion exchanger bed, also known as the high - efficiency anion exchanger.

[0033] The mixed bed, also known as the anion - cation mixed ion exchange column. It is to mix a certain proportion of cation and anion exchange resins and load them into the same exchange device to exchange and remove ions in the fluid.

[0034] 1. Strengthening synergy: Integrating the original scattered improvements into a collaborative module for systematic design; 2. The synergistic effect of waste heat recovery and high - efficiency desalination, and the linkage mechanism of intelligent control and resource closed - loop; 3. Economic benefits (annual savings of more than 3 million yuan) and technical indicators (water recovery rate of 70% - 80%).

[0035] The process after transformation: Raw water tank (reusing existing equipment) → Fiber filter → High - efficiency cation exchanger bed → Decarbonator + Intermediate water tank → High - efficiency anion exchanger bed → Mixed bed (reusing existing equipment) → Demineralized water tank (reusing existing equipment).

[0036] The water quality of the primary demineralized water outlet is controlled with a conductivity of 1 - 20 μs / cm (during operation, most of the time, the conductivity ≤ 3.0 μs / cm), and the water quality of the secondary demineralized water has a conductivity less than 0.2 μs / cm and SiO2 less than 20.0 μg / L (reusing the existing mixed bed).

Claims

1. A collaborative optimization method for a desalted water system, characterized in that This method reduces system energy consumption, improves water recovery rate, reduces wastewater discharge and even achieves zero wastewater discharge through the synergistic effect of waste heat recovery, intelligent backwash control, efficient desalination technology and resource recycling in the process of desalted water.

2. The collaborative optimization method for a desalted water system according to claim 1, wherein The process of the desalination system is: A grey water and raw water heat exchanger is arranged upstream of the raw water tank. The grey water is cooled by heat exchange in the grey water and raw water heat exchanger, and the fresh raw water is heated by heat exchange in the grey water and raw water heat exchanger and then connected to the raw water tank. The raw water tank is connected to the ultrafilter. The water channel downstream of the ultrafilter is connected to the top of the fiber filter, and the water channel at the bottom of the fiber filter is connected to the bottom of the high-efficiency cationic bed; After cation exchange, the water channel at the top of the high-efficiency cation bed is connected to the decarbonizer, and the bottom of the decarbonizer is connected to the intermediate water tank; The intermediate water tank is connected to the bottom of the high-efficiency anion bed through a process pump. After anion exchange, the water channel at the top of the high-efficiency anion bed is connected to the top of the mixed bed. The water channel at the bottom of the mixed bed is connected to the desalted water tank.

3. A desalted water system collaborative optimization method according to claim 2, characterized in that: A backwash water channel is also provided between the raw water tank and the ultrafilter.

4. A desalted water system collaborative optimization method according to claim 1, characterized in that: A backwash water channel is set from the top of the mixed bed to the ultrafilter.

5. A desalted water system collaborative optimization method according to claim 1, characterized in that: In the desalination system, Differential pressure sensor, PLC controller, backwash inlet valve, backwash pump, drain valve, Timer, equipped with periodic triggering backwash pump; the backwash pump is connected to a spare drain valve; A flow sensor is arranged on the backwash pipeline of the backwash pump, and the flow sensor is equipped with an alarm module.

6. A desalted water system collaborative optimization method according to claim 5, characterized in that: The flow sensors installed on the pipelines are all connected to the DCS control system. The DCS control system automatically adjusts the flow solenoid valves of the monitored process pipelines through decentralized control and centralized management.

7. A desalted water system collaborative optimization method according to claim 5, characterized in that: The raw water is heated to 25°C by the plate heat exchanger using the waste heat of the grey water and then enters the raw water tank, ultrafilter and fiber filter; The high-efficiency cation bed and high-efficiency anion bed are connected in series downstream for desalination, and the pH is adjusted by adding alkali to the influent through secondary reverse osmosis, and the final produced water is refined by a mixed bed; The ultrafilter backwash cycle is dynamically adjusted by the intelligent backwash control system, and the backwash water is recycled to the raw water tank; The regeneration wastewater generated by the mixed bed and the drainage from the neutralization pool are sent back to the ultrafilter backwash system through the recovery pump; The system operation data is monitored in real time, and the linkage control of waste heat recovery, backwash frequency and pH value is achieved through PLC.

8. A method for collaborative optimization of a desalted water system according to claim 7, characterized in that: This method reduces system energy consumption, improves water recovery rate, and achieves zero wastewater discharge through the synergistic effect of waste heat recovery, intelligent backwash control system control, anion bed, cation bed, and mixed bed high-efficiency desalination technology, and resource recycling; The waste heat recovery uses the waste heat of gasified ash water and the plate heat exchanger to heat the raw water so that the raw water temperature is stably controlled at 25±2℃; The intelligent backwash control system dynamically adjusts the ultrafiltration backwash cycle and combines closed-loop recovery of backwash water.

9. A device for realizing collaborative optimization of a desalinated water system, characterized in that The system device is as follows: A greywater raw water heat exchanger is provided upstream of the raw water tank. The greywater is cooled by heat exchange in the greywater raw water heat exchanger, and the fresh raw water is heated by heat exchange in the greywater raw water heat exchanger and then connected to the raw water tank. The raw water tank is connected to an ultrafilter. The water path downstream of the ultrafilter is connected to the top of a fiber filter, and the water path at the bottom of the fiber filter is connected to the bottom of a high-efficiency cation bed. After cation exchange, the water path at the top of the high-efficiency cation bed is connected to a decarbonator, and the bottom of the decarbonator is connected to an intermediate tank. The intermediate tank is connected to the bottom of a high-efficiency anion bed through a process pump. After anion exchange, the water path at the top of the high-efficiency anion bed is connected to the top of a mixed bed. The water path at the bottom of the mixed bed is connected to a demineralized water tank. A backwash water path is also provided between the raw water tank and the ultrafilter. A backwash water path is provided from the top of the mixed bed to the ultrafilter. The pipeline flow configuration of the raw water is as follows: Raw water tank → fiber filter → high-efficiency cation bed → decarbonator + intermediate tank → high-efficiency anion bed → mixed bed → demineralized water tank.

10. Application of a method for collaborative optimization of a demineralized water system according to any one of claims 1 to 8 in a water treatment process.

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