A circulating cooling water concentration rate control method and circulating cooling water system

Abstract

The present invention provides a control method for circulating cooling water concentration ratio and a circulating cooling water system, comprising a cooling tower, a circulating water pool, a first circulating water pipeline, a second circulating water pipeline, a sewage pipeline, a water supply pipeline, and a condenser, wherein the circulating water output end of the circulating water pool is connected to one end of the water side of the condenser through the first circulating water pipeline, and the other end of the water side of the condenser is connected to the circulating water input end of the cooling tower through the second circulating water pipeline, a pH sensor and a second conductivity meter are arranged on the second circulating water pipeline, and the pH sensor is close to the condenser, a first conductivity meter and a second control valve are arranged on the water supply pipeline in sequence, and a first control valve is arranged on the sewage pipeline. Using the method of the present invention, the circulating water concentration ratio can be increased, water resources can be saved, and the pollution of the circulating water sewage to the environment can be reduced, and the added raw materials are more environmentally friendly, with good economic and social benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of circulating water management, and in particular to a method for controlling a concentration ratio of circulating cooling water and a circulating cooling water system. Background Art

[0002] The raw water is treated and added to the circulating water system. The circulating water pump transports the cooling water from the tower pool to the heat exchanger. After passing through the heat exchanger, the circulating water returns to the tower pool after being sprayed by the cooling tower to dissipate heat and is recycled again, thus forming a water circulation system. The circulating water will evaporate after being heated, causing evaporation losses. The salt content of the circulating water will increase. When the salt content of the circulating water increases to a certain value, problems such as corrosion and scaling of the circulating water system will occur. In order to maintain the safe and stable operation of the circulating water, the salt content of the circulating water needs to be monitored and controlled. The method of controlling the concentration ratio of the circulating water is usually used to control the salt content of the circulating water. The ratio of the salt content of the circulating water to the make-up water is defined as the concentration ratio (K). The water replenishment and sewage discharge of the circulating water system are inversely correlated with the K value.

[0003] Traditional circulating cooling water concentration ratio supervision: Manually measure and calculate the salt content (dissolved solids) ratio of circulating water to make-up water as the concentration ratio. You can also manually detect and measure the chloride ion or calcium ion, the ratio of chloride ion or calcium ion in circulating water, and roughly calculate the circulating water concentration ratio.

[0004] The prior art with publication number CN102681452A discloses a circulating water system control method, the process of which is: (1) Obtaining the limit concentration ratio of the circulating water through a scale inhibition test. (2) Determining the limit value of the chloride ion concentration ratio, the hardness limit value and the alkalinity limit value of the circulating water at the limit concentration ratio. (3) Formulating a chloride ion concentration ratio for safe circulating water operation control, and determining the control indicators of alkalinity and hardness. (4) Detecting the alkalinity and hardness of the circulating water. (5) Observing whether the alkalinity test value and the hardness test value of the circulating water meet the control indicators. If one or both of the alkalinity test value or the hardness test value do not meet the control indicators, the circulating water needs to be treated and adjusted before being tested. (6) If both the alkalinity test value and the hardness test value meet the control indicators, the test ends. The low concentration ratio in the prior art leads to large water consumption and sewage discharge, and the effectiveness of the water treatment agent cannot be fully utilized. Chloride ions are used to calculate the concentration ratio of circulating water, and manual chloride ion detection is required. The detection test requires chemical agents, which endangers the personal safety of operators, and the test waste liquid needs to be treated, which wastes financial, material and human resources and has high economic costs. Summary of the invention

[0005] In view of this, the present invention aims to propose a control method for the concentration ratio of circulating cooling water. In order to solve the problem that the concentration ratio in the prior art is low, resulting in large water consumption and sewage discharge, and the efficiency of water treatment agents cannot be fully utilized, and the circulating water concentration ratio is calculated by using salt content or chloride ion and calcium ion, and salt content or chloride ion and calcium ion detection is required, and the detection test requires chemical agents, which endangers the personal safety of operators, and the test waste liquid needs to be treated, which wastes financial, material and human resources and has high economic costs.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A circulating water cooling system comprises a cooling tower, a circulating water pool, a first circulating water pipeline, a second circulating water pipeline, a sewage pipeline, a water supply pipeline and a condenser, wherein the circulating water output end of the circulating water pool is connected to one end of the water side of the condenser through the first circulating water pipeline, and the other end of the water side of the condenser is connected to the circulating water input end of the cooling tower through the second circulating water pipeline, a pH sensor and a second conductivity meter are arranged on the second circulating water pipeline, and the pH sensor is close to the condenser, a first conductivity meter and a second control valve are arranged on the water supply pipeline, and a first control valve is arranged on the sewage pipeline.

[0008] This setting enables the open cooling water circulation system to implement the introduction of microbial preparations and nutrients, and according to the circulating cooling water makeup water quality, it can increase the circulating cooling water rate, achieving the cooling system's treatment goals of preventing scale and corrosion, and avoiding algae growth and slime.

[0009] Furthermore, it also includes transmitting the collected data of the pH sensor, the first conductivity meter and the second conductivity meter to a remote overall monitoring network server via wireless data, and obtaining relevant data by accessing the server through an Internet-connected client. When the pH sensor detects that the pH of the circulating water is between 7.5 and 8.5, the mobile phone will receive an alarm text message.

[0010] This setting completely avoids the safety and economic problems caused by circulating cooling water out of control due to manual control, and the alarm signal of pH exceeding the standard is an overall protection for the open circulating cooling water system, extending the service life of the unit.

[0011] A method for controlling the concentration ratio of circulating cooling water, using the above-mentioned system, comprises the following steps:

[0012] S1: Install an open circulating water cooling system;

[0013] S2: The open circulating cooling water system is started, and scale inhibitors, corrosion inhibitors, microbial preparations and nutrients are added to the circulating cooling water in sequence. The operating data H0 of the pH sensor is monitored. When H0 begins to decrease, it means that the active microorganisms have adapted to the circulating cooling water quality. Continue to monitor H0 to confirm whether it has entered the circulating cooling water concentration stage.

[0014] S3: In the circulating cooling water concentration stage, the opening of the second control valve is controlled, and the circulating water concentration rate limit value Kmax and the second conductivity standard data A are determined according to the monitoring data of the first conductivity meter and the second conductivity meter. 标 ;

[0015] S4: Control the opening of the first control valve and / or the second control valve, monitor the data of the first conductivity meter and the second conductivity meter, and make the circulating cooling water system operate when the circulating water concentration ratio K1 is the first preset value ≤ K1 ≤ Kmax and the second conductivity operation data A1 is less than A 标 Run below.

[0016] This setting can greatly increase the concentration rate of the circulating cooling water system, reduce the amount of water to be replenished and the amount of sewage discharged, avoid the use of chemical agents, avoid secondary pollution, simplify chemical technical supervision, reduce employee labor intensity, and has significant economic, safety, social and ecological benefits.

[0017] Furthermore, the circulating water concentration ratio limit Kmax is controlled between 12 and 15 times.

[0018] This arrangement enables the open circulating cooling water system to achieve significant water-saving and emission-reduction effects, and reduces the scaling and corrosion tendency of the circulating water.

[0019] Preferably, if the circulating water concentration ratio limit Kmax is too high, the scaling and corrosion tendency of the circulating water will increase, which is not conducive to safe operation.

[0020] Furthermore, step S2 includes:

[0021] S21: When H0 starts to decrease, it means that the active microorganisms have adapted to the water quality of the circulating cooling water, and H0 continues to be monitored, and step S22 is executed;

[0022] S22: When H0<8, close the first control valve and enter the circulating cooling water concentration stage;

[0023] S23: When H0>8, add nutrients to the circulating water and execute step S24;

[0024] S24: According to the detection data H0' of the pH sensor, determine whether H0' is greater than 8, if so, execute step S23, if not, execute step S22.

[0025] This setup makes open-loop cooling water treatment more environmentally friendly.

[0026] Furthermore, step S4 further includes the following steps:

[0027] S41: when K1 is less than the first preset value, the opening of the first control valve is reduced to reduce the amount of water replenishment;

[0028] S42: when K1>Kmax, increase the opening of the first control valve and increase the water replenishment amount;

[0029] S43: When the first preset value ≤ K1 ≤ Kmax, the normal operation of the circulating cooling water system is maintained.

[0030] This setting enables the circulating water concentration rate to be controlled within a relatively high range, thereby saving energy and reducing emissions, and achieving the treatment goals of preventing scale and corrosion in the circulating cooling system, and avoiding the growth of algae and slime.

[0031] Preferably, the first preset value cannot be too low, the concentration ratio is low, the water consumption and sewage discharge are large, and the efficiency of the microorganisms cannot be fully exerted, which is not conducive to the economic operation of the power plant.

[0032] Furthermore, step S4 also includes adding 200-300 kg of nutrient agent into the circulating cooling water system every 1-3 days.

[0033] This setting keeps the circulating cooling water system running for a long time, prevents corrosion, scaling and microbial growth in the circulating cooling water system, and ensures the safe, stable, economical and environmentally friendly operation of the circulating cooling water system.

[0034] Furthermore, it also includes monitoring the sensitivity of the circulating cooling water quality to the addition of nutrients every 10 to 20 days after the circulating cooling water system is used, and appropriately supplementing the microbial preparation.

[0035] This setting prevents corrosion, scaling and microbial growth in the open circulating cooling water system, ensuring the safe, stable, economical and environmentally friendly operation of the circulating cooling water system.

[0036] Furthermore, step S2 also includes adding a bactericide to the circulating cooling water tower for sterilization 5-10 days in advance before the open circulating cooling water system is started.

[0037] Furthermore, the calculation formula of the circulating water concentration ratio K1 is as follows: K1=A y / A x

[0038] Where: A x —Measurement value of the first conductivity meter; A y —Measurement value of the second conductivity meter.

[0039] Compared with the prior art, the method for controlling the concentration ratio of circulating cooling water and the open circulating cooling water system described in the present invention have the following advantages:

[0040] 1) The present invention adds chemical agents such as scale inhibitors and corrosion inhibitors, sulfuric acid, bactericides and algaecides, and slime stripping agents to the open industrial circulating cooling water, and uses the screened, cultured, and domesticated beneficial microbial flora and suitable nutrient regulators to perform microbial chemical treatment on the open circulating cooling water. According to the water quality of the circulating cooling water replenishment, the circulating cooling water rate can be increased to about 12-15 times, while the circulating water cooling system can be scaled and corrosion inhibited, and algae breeding and slime prevention can be achieved. This not only facilitates the operation control of the circulating water, but also maximizes the use of water resources, saves funds, and ensures the safe and stable operation of the circulating water system;

[0041] 2) The present invention installs a first conductivity meter and a second conductivity meter on the first circulating water pipeline and the second circulating water pipeline, and controls the circulating cooling water replenishment and circulating water concentration ratio through the corresponding relationship between the first conductivity meter, the second conductivity meter and the salt content, so that the circulating water quality adjustment is faster and more convenient;

[0042] 3) The control method of the present invention has the advantages of simple operation, easy control, and strong adaptability. It can increase the concentration rate of circulating water, save water resources, and reduce the pollution of circulating water sewage to the environment. The added raw materials are more environmentally friendly and have good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the overall structure of the circulating water cooling water system of the present invention;

[0044] Figure 2 The present invention is a flow chart of a method for controlling the concentration ratio of circulating water.

[0045] Description of reference numerals:

[0046] 1-cooling tower, 2-circulating water pool, 3-sewage pipe, 31-first control valve, 4-water supply pipe, 41-first conductivity meter, 42-second control valve, 5-circulation pump, 6-pH sensor, 7-second conductivity meter, 8-first circulating water pipe, 9-condenser, 10-second circulating water pipe, 11-dosing pipe, 111-dosing box, 112-dosing pump. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Example

[0048] The present invention relates to a method for controlling the concentration ratio of circulating water, comprising the following steps:

[0049] Step 1: Installation of open circulating water cooling system;

[0050] Specifically, the open circulating cooling water system includes a cooling tower 1, a circulating water pool 2, a sewage pipe 3, a first control valve 31, a water supply pipe 4, a first conductivity meter 41, a second control valve 42, a circulating pump 5, a pH sensor 6, a second conductivity meter 7, a first circulating water pipe 8, a condenser 9, a second circulating water pipe 10, a dosing pipe 11, a dosing box 111, and a dosing pump 112;

[0051] Among them, the circulating water output end of the circulating water pool 2 is connected to one end of the water side of the condenser 9 through the first circulating water pipe 8, the other end of the water side of the condenser 9 is connected to the circulating water input end of the cooling tower 1 through the second circulating water pipe 10, and the dosing pipe 11 is connected to the second circulating water pipe 10.

[0052] Preferably, a 220V fixed power supply is selected near the condenser and connected to the upper grid plate of the drainage pump pit, one for each of Units 1 and 2, with a power of 0.5kW each, for the power supply of the circulating cooling water conductivity meter and the online pH meter).

[0053] Specifically, a circulating pump 5 and a condenser 9 are sequentially arranged on the first circulating water pipeline 8 .

[0054] The first circulating water pipeline 8 is provided with a pH sensor 6 and a second conductivity meter 7 in sequence. In the present application, the open circulation system is equipped with a pH sensor to monitor the pH value of the circulating cooling water, and the second conductivity meter can detect the water quality of the circulating water online.

[0055] Specifically, the sewage pipe 3 is connected to the circulating water pool 2, and a first control valve 31 is provided on the sewage pipe 3. In the present application, the sewage flow rate can be adjusted according to the opening of the first control valve to ensure that the conductivity of the circulating cooling water is within a certain range.

[0056] Specifically, the water supply pipe 4 is connected to the circulating water pool 2, and a second control valve 42 and a first conductivity meter 41 are provided on the water supply pipe 4. In the present application, the water supply flow rate can be adjusted according to the opening of the second control valve to ensure that the concentration ratio of the circulating cooling water is within a certain range. The first conductivity meter can detect the water quality of the circulating water online.

[0057] Specifically, the dosing pipe 11 is provided with a dosing box 111 and a dosing pump 112. In the present application, the water quality of the circulating water can be detected according to the pH sensor, the first conductivity meter and the second conductivity meter. When adding drugs and discharging sewage, the dosing pump provides power to add the required agents to the dosing box to meet the requirements of the circulating water quality standards, wherein the correspondence between the conductivity of different water sources and the salt content.

[0058] Step 2: The biochemical startup process of the circulating cooling water includes opening the first control valve and the second control valve, adding scale inhibitors, corrosion inhibitors, microbial preparations and nutrients to the circulating cooling water in sequence, and monitoring the operating data H0 of the pH sensor. When H0 starts to decrease, it indicates that the active microorganisms have adapted to the circulating cooling water quality. Continue to monitor H0. When H0 is greater than 8, add nutrients to the circulating water. When H0 is less than 8, it indicates that the microbial activity meets the circulating cooling water treatment requirements. Close the first control valve and enter the circulating cooling water concentration stage.

[0059] Specifically, before the open circulating cooling water system is started, bactericide is added to the circulating cooling water tower for sterilization 7 days in advance, the activated microbial preparation and nutrient agent are added to the dosing box, powered by the dosing pump and put into the dosing pipeline, and then enter the circulating cooling water system and finally reach the circulating cooling water tower. The original treatment method of adding scale inhibitors and corrosion inhibitors is maintained, and nutrients are added regularly and the water quality of the circulating cooling water is monitored. When the pH value of the circulating cooling water begins to decrease, generally within 2 days, it proves that the active microorganisms in the biochemical treatment of the circulating cooling water have basically adapted to the water quality of the circulating cooling water and have begun to enter a normal life metabolism state. The pH of the circulating cooling water continues to be monitored. When the pH drops below 8.0, it indicates that the microbial activity has met the circulating cooling water treatment requirements and can work normally. At this time, stop adding scale inhibitors and corrosion inhibitors, close the sewage gate, and enter the stage of increasing the concentration rate of the circulating cooling water.

[0060] Step 3: During the circulating cooling water concentration stage, the opening of the second control valve is controlled, and according to the monitoring data of the first conductivity meter and the second conductivity meter, the circulating water concentration rate limit value Kmax and the standard data A of the second conductivity meter are determined by the calculation formula of the circulating water concentration rate limit value Kmax: Kmax=A2 / A1, where: A1 is the monitoring value of the first conductivity meter; A2 is the monitoring value of the second conductivity meter. 标 , A 标 =A2;

[0061] Step 4: Control the opening of the first control valve and / or the second control valve, monitor the data of the first conductivity meter and the second conductivity meter, and make the circulating cooling water system operate when the circulating water concentration ratio K1 is the first preset value ≤ K1 ≤ Kmax and the second conductivity operation data A1 is less than A 标When K1 is less than the first preset value, the opening of the first control valve is reduced to reduce the amount of water replenishment. When K1 is greater than the concentration ratio limit value, the opening of the first control valve is increased to increase the amount of water replenishment. The calculation formula of the circulating water concentration ratio K1 is: K1=A y / A x , where: A x —The measured value of the first conductivity meter; Ay —The measured value of the second conductivity meter.

[0062] Specifically, the circulating water concentration ratio is adjusted according to the chloride ion concentration of the replenishing water. For example, the chloride ion concentration of the circulating cooling water replenishing water is 63.5 mg / L, and the chloride ion concentration in the circulating cooling water is controlled not to exceed 1000 mg / L, and the circulating water concentration ratio is controlled below 15 times. The concentration ratio of the circulating cooling water after biochemical treatment can be obtained by monitoring the ratio of the first conductivity meter and the second conductivity meter. If the concentration ratio is too low, the replenishing water amount is reduced, thereby increasing the circulating cooling water concentration ratio and reducing the sewage discharge amount. If the circulating concentration ratio is too high, the replenishing water amount is increased to reduce the circulating cooling water concentration ratio.

[0063] More specifically, when the concentration ratio limit of circulating cooling water is 12 times, the first control valve is opened to control the sewage flow rate by adjusting the opening of the first control valve to ensure that the conductivity of the circulating cooling water operates within the range of 4800μs / cm to 5000μs / cm, so as to avoid corrosion of stainless steel pipes such as condensers. The purpose of supervising the chloride ion concentration of circulating water in high concentration ratios is achieved mainly by monitoring the change in conductivity before and after. Considering the condenser is made of 316L stainless steel, if the chloride ion concentration is controlled not to exceed 1000mg / L, the conductivity meter display value at the condenser outlet must not exceed 5000us / cm, and the concentration ratio must not exceed 12 times.

[0064] Monitoring method: On-site monitoring of pH sensor, first conductivity meter and second conductivity meter data is transmitted in real time (every 30 seconds) via wireless data (data flow card of mobile telecommunications company) to the remote monitoring network server, and the server is accessed through the Internet client (desktop browser or Android phone with app software) to obtain relevant data. If the pH exceeds the standard, the mobile phone will receive an alarm SMS.

[0065] When the operation starts, it is basically unnecessary to add microbial agents again after adding them. According to the water quality index of circulating cooling water, 200kg to 300kg of microbial nutrient agents can be directly added every day. Appropriate adjustments can be made under special circumstances. After 15 days, microbial agents should be appropriately supplemented according to the sensitivity of circulating cooling water quality to the addition of nutrient agents.

[0066] When the open circulation system is running, the pH sensor, the first conductivity meter, and the second conductivity meter transmit the collected data to the remote overall monitoring network server via wireless data, and access the server through the Internet client to obtain relevant data. When the pH sensor detects that the pH of the circulating water is between 7.5 and 8.5, the mobile phone will receive an alarm text message.

[0067] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A circulating cooling water system, characterized in that: It includes a cooling tower, a circulating water pool, a first circulating water pipeline, a second circulating water pipeline, a sewage pipeline, a water supply pipeline, a condenser, a dosing pipeline, a dosing box, and a dosing pump. The circulating water output end of the circulating water pool is connected to one end of the water side of the condenser through the first circulating water pipeline, and the other end of the water side of the condenser is connected to the circulating water input end of the cooling tower through the second circulating water pipeline. The second circulating water pipeline is provided with a pH sensor and a second conductivity meter, and the pH sensor is close to the condenser. The water supply pipeline is provided with a first conductivity meter and a second control valve in sequence, and the sewage pipeline is provided with a first control valve; the dosing pipeline is connected to the second circulating water pipeline, and the dosing box and the dosing pump are provided on the dosing pipeline; The method for controlling the concentration ratio of circulating cooling water of the system comprises the following steps: S1: Install an open circulating water cooling system; S2: The open circulating cooling water system is started, and antiscalant, corrosion inhibitor, microbial preparation and nutrient are added to the circulating cooling water in sequence, and the operation data H0 of the pH sensor is monitored to confirm whether the circulating cooling water concentration stage has been entered; Step S2 includes: S21: When H0 starts to decrease, it means that the active microorganisms have adapted to the water quality of the circulating cooling water, and H0 continues to be monitored, and step S22 is executed; S22: When H0<8, close the first control valve and enter the circulating cooling water concentration stage; S23: When H0>8, add nutrients to the circulating water and execute step S24; S24: judging whether H0' is greater than 8 according to the detection data H0' of the pH sensor, if so, executing step S23, if not, executing step S22; S3: In the circulating cooling water concentration stage, the opening of the second control valve is controlled, and the circulating water concentration rate limit value Kmax and the standard data A of the second conductivity table are determined according to the monitoring data of the first conductivity table and the second conductivity table. 标 ; S4: Control the opening of the first control valve and / or the second control valve so that the circulating cooling water system is closed when the circulating water concentration ratio K1 is a first preset value ≤ K1 ≤ Kmax and the second conductivity operation data A1 is less than A 标 Run below; Step S4 also includes the following steps: S41: when K1 is less than the first preset value, the opening of the first control valve is reduced to reduce the amount of water replenishment; S42: When K1>Kmax, increase the opening of the first control valve to increase the water replenishment amount; S43: When the first preset value ≤ K1 ≤ Kmax, maintaining the normal operation of the circulating cooling water system; The circulating water concentration ratio limit Kmax is controlled between 12 and 15 times; The calculation formula of the circulating water concentration ratio K1 is as follows: K1 = A y / A x , where: A x —Measurement value of the first conductivity meter; A y —Measurement value of the second conductivity meter.

2. The system according to claim 1, characterized in that It also includes transmitting the collected data of the pH sensor, the first conductivity meter and the second conductivity meter to a remote overall monitoring network server via wireless data, and obtaining relevant data by accessing the server through an Internet-connected client. When the pH sensor detects that the pH of the circulating water is between 7.5 and 8.5, the mobile phone will receive an alarm text message.

3. The system according to claim 1 further comprises monitoring the sensitivity of the circulating cooling water quality to the addition of nutrients and supplementing the microbial preparation every 10 to 20 days after the circulating cooling water system is used.

4. The system according to claim 1, characterized in that Step S4 also includes adding 200-300 kg of nutrient agent into the circulating cooling water system every 1-3 days.

5. The system according to claim 1, characterized in that Step S2 also includes adding a bactericide to the circulating cooling water tower for sterilization 5-10 days in advance before the open circulating cooling water system is started.

Images