High-speed mixed bed equipment for fine treatment of condensed water in thermal power plant

Abstract

The invention provides high-speed mixed bed equipment for fine treatment of condensed water of a thermal power plant, and belongs to the field of water treatment of the thermal power plant, the high-speed mixed bed equipment comprises a regeneration system, a control system and a high-speed mixed bed, the high-speed mixed bed is communicated with the regeneration system, and the regeneration system and the high-speed mixed bed are both electrically connected with the control system. According to the high-speed mixed bed equipment, the water distribution uniformity is remarkably improved, so that the utilization rate and the periodic water control amount of resin are remarkably improved, and the stability of the effluent quality is improved; the resin abrasion is reduced, the service life of the resin is prolonged, and the operation cost is reduced; the regeneration efficiency is improved, the consumption of a regeneration agent is reduced, and the discharge of regeneration wastewater is reduced; the equipment cost and the maintenance workload are reduced; the operation flexibility and reliability of the system are improved; and a modular design is adopted, so that capacity expansion and transformation are facilitated.

Description

Technical Field

[0001] This invention relates to the field of water treatment in thermal power plants, and more specifically to a high-speed mixed bed device for condensate polishing in thermal power plants. Background Technology

[0002] In thermal power plants, condensate is formed by the condensation of exhaust steam after the turbine has performed its work. The quality of the condensate directly affects the safe and economical operation of the boiler. Condensate usually contains trace amounts of impurities, such as metal oxides, silicates, and various ions, and needs to be deeply purified through a fine treatment system to meet boiler feedwater standards.

[0003] High-speed mixed beds are key equipment in condensate polishing systems, their main function being to remove various ionic impurities from condensate through a mixture of cation and anion exchange resins. Traditional high-speed mixed beds typically employ a large-diameter cylindrical structure (usually larger than DN2200) to meet high-flow-rate treatment requirements. However, large-diameter high-speed mixed beds have the following drawbacks: 1. Uneven water distribution. Due to the large diameter of the cylinder, the initial distribution of influent within the bed is difficult to be uniform, easily leading to channeling and short-circuiting. This causes water flow deviation, resulting in reduced resin utilization, premature resin failure in some areas, and affecting effluent quality and cycle water production. This unevenness also affects the uniform distribution of regenerated solution within the bed, reducing regeneration efficiency and increasing the consumption of regeneration reagents.

[0004] 2. Risk of bed fluidization. Large-diameter beds are prone to fluidization during operation, especially at high flow rates, which can lead to accelerated resin wear and affect the service life of the resin.

[0005] 3. The equipment is difficult to manufacture, transport, and maintain. The manufacturing, transportation, and on-site installation of large-diameter cylinders are all difficult, costly, and involve a large amount of maintenance work and long maintenance cycles.

[0006] Therefore, we propose a high-speed mixed bed device for condensate polishing in thermal power plants. Summary of the Invention

[0007] The purpose of this invention is to provide a high-speed mixed bed device for condensate polishing in thermal power plants, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a high-speed mixed bed device for condensate polishing in thermal power plants, comprising a regeneration system, a control system, and a high-speed mixed bed. The high-speed mixed bed is connected to the regeneration system, and both the regeneration system and the high-speed mixed bed are electrically connected to the control system. Furthermore, the high-speed mixed bed is provided with a number of small-diameter cylindrical ion exchangers, and the number of such small-diameter cylindrical ion exchangers are arranged in parallel.

[0009] Furthermore, the diameter of each small-diameter cylindrical ion exchanger is DN150-DN300.

[0010] Furthermore, each small-diameter cylindrical ion exchanger includes a cylindrical body, one end of which is a water inlet end, on which a water inlet distributor is installed, and the other end of which is a water outlet end, on which a water outlet collector is installed. The interior of the cylindrical body is filled with resin, which is located in the space between the water inlet distributor and the water outlet collector.

[0011] Furthermore, the resin is a mixture of a strongly acidic cation exchange resin and a strongly basic anion exchange resin.

[0012] Furthermore, the water inlet distributor is either a perforated plate or a spray-type distributor.

[0013] Furthermore, the water outlet collector is either a water supply pipe or a perforated plate water collector.

[0014] Furthermore, each small-diameter cylindrical ion exchanger is equipped with an independent flow meter and valve body, both of which are electrically connected to the control system.

[0015] Furthermore, the regeneration system employs a countercurrent regeneration method.

[0016] Furthermore, the control system is a PLC controller.

[0017] Compared with the prior art, the present invention has the following technical effects: 1. Significantly improves water distribution uniformity: Due to the use of a small-diameter cylindrical ion exchanger, channeling and short-circuiting phenomena commonly found in large-diameter beds are effectively avoided, improving water distribution uniformity. This significantly increases resin utilization and cycle water production, and improves the stability of effluent water quality.

[0018] 2. Reduced resin wear: Small-diameter beds reduce the risk of bed fluidization, reduce resin wear during operation, extend resin service life, and reduce operating costs.

[0019] 3. Improved regeneration efficiency: The small-diameter cylindrical ion exchanger makes the water distribution and regeneration solution distribution more uniform, which improves the regeneration efficiency, reduces the consumption of regeneration reagents, and reduces the discharge of regeneration wastewater.

[0020] 4. More convenient equipment manufacturing, transportation and maintenance: The manufacturing, transportation and installation of small-diameter cylinders are more convenient than those of large-diameter cylinders, reducing equipment costs and maintenance workload.

[0021] 5. High system flexibility and reliability: Multiple small-diameter cylindrical ion exchangers operate in parallel, improving the system's operational flexibility and reliability. When some cylinders require maintenance or regeneration, the others can continue operating, ensuring continuous system operation.

[0022] 6. Modular design is possible: This parallel structure enables modular design, allowing for flexible configuration of the number of small-diameter cylindrical ion exchangers according to the actual needs of the power plant, facilitating capacity expansion and retrofitting. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a small-diameter cylindrical ion exchanger according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a parallel arrangement of small-diameter cylindrical ion exchangers according to an embodiment of the present invention.

[0024] In the diagram: 1. Small-diameter cylindrical ion exchanger, 2. Cylinder, 3. Inlet water distributor, 4. Outlet water collector, 5. Resin, 6. Inlet end, 7. Outlet end. Detailed Implementation

[0025] The technical solutions of 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 a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0026] In this article, terms such as "left," "right," "up," "down," "front," and "back" are established based on the positional relationships shown in the attached drawings. Depending on the attached drawings, the corresponding positional relationships may also change. Therefore, they should not be interpreted as an absolute limitation on the scope of protection.

[0027] Please see Figures 1 to 2 This embodiment provides a high-speed mixed bed device for condensate polishing in thermal power plants, including a regeneration system, a control system, and a high-speed mixed bed. In this embodiment, the control system can be a PLC controller. The high-speed mixed bed is electrically connected to the control system. The control system can monitor and control the operating status (e.g., flow rate, pressure, conductivity, etc.) of each small-diameter cylindrical ion exchanger 1 in the high-speed mixed bed, and perform switching and regeneration operations as needed, thereby achieving optimized operation and automated control of the equipment.

[0028] Specifically, the regeneration system is connected to the high-speed mixed bed and is used to regenerate the failed resin 5 in the high-speed mixed bed. All small-diameter cylindrical ion exchangers 1 in the high-speed mixed bed share a single regeneration system. It should be noted that the regeneration system uses existing products, which consist of a regeneration solution preparation unit, a conveying unit, and a discharge unit, etc. Therefore, this embodiment will not describe the structure and working principle of the regeneration system in detail. When regenerating the failed resin 5, the regeneration system can use either co-current or counter-current regeneration methods, with counter-current regeneration being preferred to improve regeneration efficiency. The regeneration system is electrically connected to the control system, which can monitor and control the operating status of the regeneration system.

[0029] Specifically, the high-speed mixed bed includes several small-diameter cylindrical ion exchangers 1, which are connected in parallel. Each small-diameter cylindrical ion exchanger 1 has a diameter of DN150-DN300, preferably DN200. The total processing capacity of the high-speed mixed bed using multiple small-diameter cylindrical ion exchangers 1 is equal to that of a corresponding large-diameter high-speed mixed bed.

[0030] Specifically, each small-diameter cylindrical ion exchanger 1 is equipped with an independent inlet water distributor 3 and an outlet water collector 4, thereby ensuring uniform water flow distribution and avoiding mutual interference between the cylinders 2. Each small-diameter cylindrical ion exchanger 1 includes a cylinder 2, one end of which (i.e., the top of the cylinder 2) is the inlet end 6, which is connected to a main pipe for conveying untreated condensate. The inlet water distributor 3 is installed at the inlet end 6, and the inlet water distributor 3 can be either a perforated plate or a spray-type distributor. The other end of the cylinder 2 (i.e., the bottom of the cylinder 2) is the outlet end 7, which is connected to a pipe for conveying condensate treated by the resin 5. The outlet water collector 4 is installed at the outlet end 7, and the outlet water collector 4 can be either a water supply pipe or a perforated plate collector. The cylinder 2 is filled with resin 5, which is located in the space between the inlet water distributor 3 and the outlet water collector 4. Resin 5 is a mixture of strong acid cation exchange resin and strong base anion exchange resin. The ratio of resin 5 is optimized and adjusted according to the actual condensate water quality.

[0031] Specifically, each small-diameter cylindrical ion exchanger 1 is equipped with an independent flow meter, measuring tool, and valve body to achieve precise flow control and regulation. The flow meter is used to measure the flow rate of condensate within the cylinder 2. The measuring tool is used to measure various parameters of the condensate; the specific measuring tool used depends on the actual situation and is not specifically limited in this implementation. The valve body is used to control the opening and closing of the pipeline, realizing the switching of water flow direction and flow rate, etc. Various existing valve bodies can be used, and the specific valve body used is determined based on the actual situation; this implementation is not specifically limited in this regard. The flow meter, measuring tool, and valve body are all electrically connected to the control system. The control system can receive data from the flow meter and measuring tool, and then send signals to various valve bodies based on the transmitted data to control their operation.

[0032] Specifically, to further illustrate this high-speed mixed bed equipment, the following description uses the actual application of this equipment in a thermal power plant as a case study, detailing its configuration, operation process, and optimization effects.

[0033] Specifically, in terms of configuration, based on the power plant's condensate treatment requirements, the high-speed mixed bed is equipped with 6 small-diameter cylindrical ion exchangers 1, each with a diameter of DN200. The 6 small-diameter cylindrical ion exchangers 1 are arranged in parallel within the high-speed mixed bed, and the total treatment capacity of the high-speed mixed bed is equivalent to that of a DN2200 single-cylinder large-diameter high-speed mixed bed.

[0034] Specifically, each small-diameter cylindrical ion exchanger 1 has a cylinder 2 with a height of 3.5 meters, and is filled with a 1:1 ratio of strong acid cation exchange resin (model 001×7) and strong base anion exchange resin (model 201×7), with a filling height of 2.8 meters. A spray-type water distributor (5mm orifice diameter, distribution density of 30 orifices / ) is installed at the top of each cylinder 2 (i.e., the water inlet 6 of cylinder 2). This ensures that the water flows evenly through the resin 5. A perforated plate water collector (8mm diameter, 40% opening rate) is installed at the bottom of the cylinder 2 (i.e., the water outlet 7 of the cylinder 2).

[0035] Specifically, each small-diameter cylindrical ion exchanger 1 is equipped with an independent flow meter (accuracy ±1%) and an electric inlet valve at its inlet end 6. The flow meter measures the flow rate of condensate at the inlet end 6 of the cylinder 2. The electric inlet valve is driven by receiving an electrical signal to regulate parameters such as the flow rate and pressure of the condensate at the inlet end 6. Both the flow meter and the electric inlet valve are electrically connected to the control system. The control system receives data from the flow meter and then sends a signal to the electric inlet valve based on the data transmitted by the flow meter, controlling the operation of the electric inlet valve.

[0036] Specifically, an independent conductivity sensor (range 0 - 10 μS / cm), a pressure transmitter (range 0 - 1.6 MPa), a multi-parameter water quality analyzer, and an electric outlet valve are installed at the water outlet end 7 of each small-diameter cylindrical ion exchanger 1. The conductivity sensor is used to monitor the conductivity change of the condensate water at the water outlet end 7, so as to facilitate the staff to understand the fine treatment effect of the condensate water; the pressure transmitter is used to monitor the pressure change at the water outlet end 7; the multi-parameter water quality analyzer is used to collect data such as the pH value, conductivity, and sodium ion concentration of the condensate water at the water outlet end 7 in real time; the electric outlet valve drives the valve by receiving an electric signal to adjust parameters such as the flow rate and pressure of the condensate water at the water outlet end 7. The conductivity sensor, the pressure transmitter, the multi-parameter water quality analyzer, and the electric outlet valve are all electrically connected to the control system. The control system can receive the data from the conductivity sensor, the pressure transmitter, and the multi-parameter water quality analyzer. Among them, the data from the multi-parameter water quality analyzer can be transmitted to the control system through the Modbus protocol. The control system sends a signal to the electric outlet valve according to the transmitted data to control the action of the electric outlet valve.

[0037] Specifically, six small-diameter cylindrical ion exchangers 1 arranged in parallel share a set of regeneration systems. The regeneration system includes a regeneration liquid storage tank (hydrochloric acid and sodium hydroxide are stored in separate tanks), a metering pump (flow adjustable range 0 - 5 m³ / h), a waste liquid neutralization tank, and a pipeline switching device. The countercurrent regeneration method is adopted, and the regeneration liquid is injected from the bottom of the cylinder and discharged from the top. The regeneration flow rate is controlled at 4 m / h. The central control host (i.e., the control system) uses a PLC controller. The PLC controller is electrically connected to the flow meters, sensors, valves of each cylinder, and the regeneration system to achieve linkage.

[0038] Specifically, the operation process specifically includes: Normal operation stage The condensate water is distributed to each small-diameter cylindrical ion exchanger 1 through the main pipe. The PLC controller controls the opening degree of the electric control valve according to the real-time flow demand (for example: the single-cylinder design flow rate is 200 m³ / h) to ensure the flow balance of each small-diameter cylindrical ion exchanger 1. The water quality data is updated every 10 seconds. If the conductivity of the water outlet end of a certain small-diameter cylindrical ion exchanger 1 exceeds the set threshold (such as 0.1 μS / cm) for three consecutive detections, the PLC controller determines that the resin 5 of this small-diameter cylindrical ion exchanger 1 has failed.

[0039] Switching and regeneration of the failed small-diameter cylindrical ion exchanger 1 Automatic withdrawal: The PLC controller immediately closes the electric inlet valve and the electric outlet valve of the failed small-diameter cylindrical ion exchanger 1, triggers an alarm prompt, and then controls the remaining small-diameter cylindrical ion exchangers 1 to increase the flow rate to maintain the total treatment capacity unchanged.

[0040] Regeneration process: Backwash: Start the backwash water pump and backwash the resin 5 of the failed small-diameter cylindrical ion exchanger 1 at a flow rate of 15 m / h for five minutes to remove trapped impurities.

[0041] Regenerant injection: The regenerant is injected sequentially using a metering pump in the order of hydrochloric acid (5% concentration) → sodium hydroxide (4% concentration). Each regeneration takes 40 minutes.

[0042] Replacement and forward washing: Replace the residual regenerant with demineralized water and forward wash until the effluent pH stabilizes at 6.5-7.5 and the conductivity is ≤0.08μS / cm. Then, the failed small-diameter cylindrical ion exchanger 1 is put back into operation.

[0043] Multiple small-diameter cylindrical ion exchangers are controlled in a coordinated manner. When more than 50% of the small-diameter cylindrical ion exchangers 1 fail simultaneously, the PLC controller starts the backup small-diameter cylindrical ion exchanger 1 (if any) and prompts the maintenance personnel to intervene through the HMI interface.

[0044] The PLC controller records the runtime, regeneration times, and water quality data of each small-diameter cylindrical ion exchanger 1 in real time, generates optimization reports, and recommends the replacement cycle of resin 5 (usually 3 years).

[0045] Specifically, regarding the implementation results: Improved water distribution uniformity Through comparative dyeing tracer experiments, the water flow distribution non-uniformity was reduced from 25% in traditional large cylinder (i.e., DN2200 single cylinder large diameter high-speed mixed bed) to 8%, the water distribution uniformity was greatly improved, and the resin utilization rate was increased to 92%.

[0046] Regeneration efficiency and cost optimization In countercurrent regeneration mode, regenerant consumption is reduced by 30%, and single regeneration time is shortened by 20%. Annual savings of hydrochloric acid and sodium hydroxide reach 12 tons and 8 tons, respectively.

[0047] Ease of operation and maintenance The small-diameter cylindrical ion exchanger features a modular design that supports online replacement. The maintenance time for a single cylinder has been reduced from 48 hours for the original large cylinder to 4 hours, and the system availability rate has been increased to 99.5%.

[0048] Environmental benefits This reduces the failure response time of resin 5 from 4 hours to within 10 seconds, prevents high-conductivity water from entering the boiler, and reduces wastewater discharge by approximately 5,000 tons per year.

[0049] Specifically, this high-speed mixed bed equipment significantly improves water distribution uniformity: Due to the use of small-diameter cylindrical ion exchangers 1, channeling and short-circuiting phenomena common in large-diameter beds are effectively avoided, improving water distribution uniformity. This significantly increases the utilization rate of resin 5 and the cycle water production, and improves the stability of effluent quality. It also reduces resin 5 wear: the small-diameter bed reduces the risk of bed fluidization, reduces resin 5 wear during operation, extends resin 5's service life, and lowers operating costs. Furthermore, it improves regeneration efficiency: the small-diameter cylindrical ion exchanger 1 makes water and regenerated liquid distribution more uniform, improving regeneration efficiency, reducing regeneration reagent consumption, and reducing regeneration wastewater discharge. The equipment is more convenient to manufacture, transport, and maintain: the small-diameter cylindrical body 2 is easier to manufacture, transport, and install than the large-diameter cylindrical body, reducing equipment costs and maintenance workload. Finally, the system offers high operational flexibility and reliability: multiple small-diameter cylindrical ion exchangers 1 operate in parallel, improving the system's operational flexibility and reliability. When some of the small-diameter cylindrical ion exchangers 1 require maintenance or regeneration, the other small-diameter cylindrical ion exchangers 1 can continue to operate, ensuring continuous system operation. Modular design is possible: This parallel structure enables modular design, allowing for flexible configuration of the number of small-diameter cylindrical ion exchangers 1 according to the actual needs of the power plant, facilitating expansion and retrofitting.

[0050] Specifically, in addition to power plants, this high-speed mixed bed equipment can also be applied to condensate polishing scenarios in other high-parameter units or nuclear power plants. For example, a 1000MW supercritical unit increased the number of small-diameter cylindrical ion exchangers from 2 to 8, successfully handling the peak flow rate of 8000m³ / h, with the silica content in the effluent consistently below 5μg / L.

[0051] The above embodiments merely illustrate the basic principles and characteristics of the present invention, but are not limited to the above implementation schemes. It should be understood that those skilled in the art can make various changes and modifications to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined freely by the appended claims and their equivalents.

Claims

1. A high-speed mixed-bed device for condensate polishing in thermal power plants, characterized in that, It includes a regeneration system, a control system, and a high-speed mixed bed. The high-speed mixed bed is connected to the regeneration system, and both the regeneration system and the high-speed mixed bed are electrically connected to the control system.

2. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 1, characterized in that, The high-speed mixed bed is provided with a number of small-diameter cylindrical ion exchangers (1), and the number of such small-diameter cylindrical ion exchangers (1) are arranged in parallel.

3. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 2, characterized in that, The diameter of each small-diameter cylindrical ion exchanger (1) is DN150-DN300.

4. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 3, characterized in that, Each small-diameter cylindrical ion exchanger (1) includes a cylindrical body (2), one end of which is a water inlet (6), and a water inlet distributor (3) is installed on the water inlet (6). The other end of the cylindrical body (2) is a water outlet (7), and a water outlet collector (4) is installed on the water outlet (7). The inside of the cylindrical body (2) is filled with resin (5), and the resin (5) is located in the space between the water inlet distributor (3) and the water outlet collector (4).

5. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 4, characterized in that, The resin (5) is a mixture of a strong acid cation exchange resin (5) and a strong base anion exchange resin (5).

6. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 5, characterized in that, The water inlet distributor (3) is either a perforated plate or a spray distributor.

7. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 6, characterized in that, The water outlet collector (4) is one of a water supply pipe or a perforated plate water collector.

8. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 7, characterized in that, Each small-diameter cylindrical ion exchanger (1) is equipped with an independent flow meter and valve body, and the flow meter and valve body are electrically connected to the control system.

9. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 1, characterized in that, The regeneration system employs either a counter-current regeneration method or a co-current regeneration method.

10. The high-speed mixed bed equipment for condensate polishing in thermal power plants according to claim 1, characterized in that, The control system is a PLC controller.

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