阅读说明：本技术 一种纯水脱气氢电导率的在线测量方法及测量装置 (On-line measuring method and measuring device for pure water degassing hydrogen conductivity ) 是由 许怀鹏 张永福 杜伟华 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种纯水脱气氢电导率的在线测量方法及测量装置,所述测量方法具体步骤为：(1)待测样水进入H+型阳离子交换柱后流出；(2)流出的样水进入脱气柱,脱气柱顶部连接射水抽气器,脱气柱内装有填料层,样水从填料层上部进入,经高效CO<Sub>2</Sub>吸收剂处理过的空气在射水抽气器的作用下从填料层下部进入；从填料层下部进入的空气与从填料层上部下淋的样水接触后,将水中的CO<Sub>2</Sub>解析出来通过射水抽气器排出；(3)脱除CO<Sub>2</Sub>后的样水自流进入电导池,此时检测的电导率即为脱气氢电导率；本发明能够保证脱气氢电导率测量值的准确性,而且设备结构简单,安装方便。(The invention discloses an on-line measuring method and a measuring device for pure water degassed hydrogen conductivity, wherein the measuring method comprises the following specific steps: (1) the sample water to be tested flows out after entering an H + type cation exchange column; (2) the effluent sample water enters a degassing column, the top of the degassing column is connected with a water jet air extractor, a packing layer is arranged in the degassing column, and the sample water enters from the upper part of the packing layer and passes through high-efficiency CO 2 The air treated by the absorbent enters from the lower part of the filler layer under the action of the water jet air extractor; the air entering from the lower part of the packing layer contacts with the sample water sprayed from the upper part of the packing layer, and then the CO in the water is treated 2 The analyzed solution is discharged through a water jet air extractor; (3) CO removal 2 The sample water automatically flows into the conductivity cell, and at the momentThe detected conductivity is the degassed hydrogen conductivity; the invention can ensure the accuracy of the conductivity measurement value of the degassed hydrogen, and has simple equipment structure and convenient installation.)

1. An on-line measuring method for pure water degassing hydrogen conductivity is characterized in that: the method comprises the following specific steps:

(1) the sample water to be tested flows out after entering an H + type cation exchange column;

(2) the effluent sample water enters a degassing column, the top of the degassing column is connected with a water jet air extractor, a packing layer is arranged in the degassing column, and the sample water enters from the upper part of the packing layer and passes through high-efficiency CO₂The air treated by the absorbent enters from the lower part of the filler layer under the action of the water jet air extractor; the air entering from the lower part of the packing layer contacts with the sample water sprayed from the upper part of the packing layer, and then the CO in the water is treated₂The analyzed solution is discharged through a water jet air extractor;

(3) CO removal₂And the sample water automatically flows into a conductivity cell, and the detected conductivity is the degassed hydrogen conductivity.

2. The method for on-line measurement of pure water degassed hydrogen conductivity according to claim 1, characterized in that: in the step (1), the inner diameter of the H + type cation exchange column is 40mm-60mm, the height is 500-600mm, and the flow rate of the sample water to be detected is not less than 200 mL/min.

3. The method for on-line measurement of pure water degassed hydrogen conductivity according to claim 1, characterized in that: in the step (2), the inner diameter of the degassing column is 1-1.5 times of that of the H + type cation exchange column, the height of the degassing column is 500-600mm, the height of the packing layer is not less than 300mm, and the specific surface area of the packing layer is not less than 350m²/m³(ii) a The upper part of the packing layer is provided with a sample water spraying nozzle, and the lower part of the packing layer is provided with an air inlet pipe.

4. The method for on-line measurement of pure water degassed hydrogen conductivity according to claim 3, characterized in that: one end of the air inlet pipe extends into the degassing column and is arranged at the lower part of the packing layer, and the other end of the air inlet pipe is provided with CO₂Absorption tube, CO₂The absorption pipe is connected with the air inlet pipe.

5. The method for on-line measurement of pure water degassed hydrogen conductivity according to claim 4, characterized in that: CO 2₂The volume of the absorption tube is not less than 200mL, and CO₂The absorption tube is provided with CO₂An absorbent; CO 2₂The inlet and the outlet of the absorption pipe are connected by a hose, and the air inlet pipe is provided with a control valve.

6. The method for on-line measurement of pure water degassed hydrogen conductivity according to claim 1, characterized in that: and (4) arranging a temperature sensor in the conductivity cell in the step (3), wherein the height of an overflow port of the conductivity cell from the bottom of the degassing column is 50-100 mm.

7. The method for on-line measurement of pure water degassed hydrogen conductivity according to claim 1, characterized in that: in the step (2), the water jet air extractor is connected with circulating cooling water, and a control water valve is arranged on an inlet pipe of the circulating cooling water; the air extraction amount of the water jet air extractor is 180L/h-360L/h; the negative pressure in the degassing column is not more than 1-2 kPa.

8. An on-line measuring device for the conductivity of pure water degassed hydrogen, which is used in the on-line measuring method for the conductivity of pure water degassed hydrogen according to any one of claims 1 to 7, and which is characterized in that: comprises an H + type cation exchange column, a degassing column and a conductivity measuring flow cell connected with the bottom end of the degassing column; the top end of the H + type cation exchange column is connected with a water inlet pipe communicated with sample water, and the bottom end of the H + type cation exchange column is connected with a water outlet pipe; a packing layer is arranged in the degassing column, and the top end of the degassing column is connected with a water jet air extractor; the water outlet pipe extends into the degassing column, and the outlet of the water outlet pipe is positioned above the packing layer; the side end of the degassing column is connected with an air inlet pipe, and one end of the air inlet pipe extends into the degassing columnThe air column is arranged below the packing layer, and the other end of the air inlet pipe is connected with CO₂Absorption tube, CO₂The absorption pipe is connected with the air inlet pipe.

9. The apparatus for on-line measurement of pure water degassed hydrogen conductivity according to claim 8, wherein: the inner diameter of the H + type cation exchange column is 40-60 mm, the height is 500-600mm, and the flow rate of sample water to be detected is not less than 200 mL/min.

10. The apparatus for on-line measurement of pure water degassed hydrogen conductivity according to claim 8, wherein: the inner diameter of the degassing column is 1-1.5 times of that of the H + type cation exchange column, the height of the degassing column is 500-600mm, the height of the packing layer is not less than 300mm, and the specific surface area of the packing layer is not less than 350m²/m³(ii) a A sample water spraying nozzle is arranged on the water outlet pipe.

Technical Field

The invention belongs to an on-line measurement technology of pure water degassing hydrogen conductivity of a thermal power plant, and particularly relates to an on-line measurement method and a measurement device of pure water degassing hydrogen conductivity.

Background

The thermal power plant needs to adjust the water quality and evaluate the water vapor quality by monitoring the hydrogen conductivity of the water vapor sample. Dissolving carbon dioxide in pure water can cause the measured value of hydrogen conductivity to be higher, and the requirement is that a water sample to be measured firstly passes through a cation exchange column, then the carbon dioxide dissolved in the water sample is removed through a degassing device, and the conductivity of the degassed water sample is measured, so that the degassed hydrogen conductivity is obtained. At present, the electrical conductivity of the degassed hydrogen is measured by commonly used degassing methods such as a boiling method, a gas purging method and a membrane degassing method. The boiling method is that the water sample is heated to the boiling point corresponding to the local atmospheric pressure to achieve the degassing effect, and the water sample is cooled to the measurement temperature after degassing. The gas purging method is to reversely spray high-purity nitrogen (the purity is not lower than 99.99%) into a water sample through a nozzle to achieve the degassing effect. The membrane degassing method is to make the water sample pass through the semipermeable membrane to achieve the degassing effect.

The three degassing modes adopted at present have the disadvantages of complex equipment structure, high price of the device, difficult maintenance and limited field use.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the online measuring method and the online measuring device for the conductivity of the pure water degassed hydrogen, which can ensure the accuracy of the conductivity measured value of the degassed hydrogen, have simple equipment structure and are convenient to install.

In order to achieve the purpose, the invention adopts the technical scheme that:

the on-line measuring method for the pure water degassing hydrogen conductivity comprises the following specific steps:

(1) the sample water to be tested flows out after entering an H + type cation exchange column;

(2) the effluent sample water enters a degassing column, the top of the degassing column is connected with a water jet air extractor, a packing layer is arranged in the degassing column, and the sample water enters from the upper part of the packing layer and passes through high-efficiency CO₂The air treated by the absorbent enters from the lower part of the filler layer under the action of the water jet air extractor; the air entering from the lower part of the packing layer contacts with the sample water sprayed from the upper part of the packing layer, and then the CO in the water is treated₂The analyzed solution is discharged through a water jet air extractor;

(3) removing ofCO₂And the sample water automatically flows into a conductivity cell, and the detected conductivity is the degassed hydrogen conductivity.

In the step (1), the inner diameter of the H + type cation exchange column is 40mm-60mm, the height is 500-600mm, and the flow rate of the sample water to be detected is not less than 200 mL/min.

In the step (2), the inner diameter of the degassing column is 1-1.5 times of that of the H + type cation exchange column, the height of the degassing column is 500-600mm, the height of the packing layer is not less than 300mm, and the specific surface area of the packing layer is not less than 350m²/m³(ii) a The upper part of the packing layer is provided with a sample water spraying nozzle, and the lower part of the packing layer is provided with an air inlet pipe.

One end of the air inlet pipe extends into the degassing column and is arranged at the lower part of the packing layer, and the other end of the air inlet pipe is provided with CO₂Absorption tube, CO₂The absorption pipe is connected with the air inlet pipe.

CO₂The volume of the absorption tube is not less than 200mL, and CO₂The absorption tube is provided with CO₂An absorbent; CO 2₂The inlet and the outlet of the absorption pipe are connected by a hose, and the air inlet pipe is provided with a control valve.

And (4) arranging a temperature sensor in the conductivity cell in the step (3), wherein the height of an overflow port of the conductivity cell from the bottom of the degassing column is 50-100 mm.

In the step (2), the water jet air extractor is connected with circulating cooling water, and a control water valve is arranged on an inlet pipe of the circulating cooling water; the air extraction amount of the water jet air extractor is 180L/h-360L/h; the negative pressure in the degassing column is not more than 1-2 kPa.

The online measuring device for the conductivity of the pure water degassed hydrogen is used for the online measuring method for the conductivity of the pure water degassed hydrogen, and comprises an H < + > type cation exchange column, a degassing column and a conductivity measuring flow cell connected with the bottom end of the degassing column; the top end of the H + type cation exchange column is connected with a water inlet pipe communicated with sample water, and the bottom end of the H + type cation exchange column is connected with a water outlet pipe; a packing layer is arranged in the degassing column, and the top end of the degassing column is connected with a water jet air extractor; the water outlet pipe extends into the degassing column, and the outlet of the water outlet pipe is positioned above the packing layer; the side end of the degassing column is connected with an air inlet pipe, one end of the air inlet pipe extends into the degassing column and is arranged below the packing layer, and the other end of the air inlet pipe is connected with CO₂Absorption tube, CO₂The absorption pipe is connected with the air inlet pipe.

The inner diameter of the H + type cation exchange column is 40-60 mm, the height is 500-600mm, and the flow rate of sample water to be detected is not less than 200 mL/min.

The inner diameter of the degassing column is 1-1.5 times of that of the H + type cation exchange column, the height of the degassing column is 500-600mm, the height of the packing layer is not less than 300mm, and the specific surface area of the packing layer is not less than 350m²/m³(ii) a A sample water spraying nozzle is arranged on the water outlet pipe.

The invention has the advantages that: in order to simplify the equipment structure and reduce the use cost, the invention provides the method and the device for measuring the conductivity of the degassed hydrogen of the pure water of the power plant.

Granular high-efficiency CO in the invention₂Residual CO in air after absorbent treatment₂The concentration can be reduced to below 4ppb, which is lower than the residual CO in the high-purity nitrogen gas specified by the standard₂The concentration and the degassed hydrogen conductivity detection accuracy are higher.

The degassed hydrogen conductivity measuring device adopting the conventional method (such as a boiling method and a gas purging method) is sold at a price of about 7-8 ten thousand yuan per set, and the hydrogen conductivity measuring device adopting the membrane degassing method is higher in price. The degassing hydrogen conductivity measuring device adopting the method has the advantages that the cost does not exceed 2 ten thousand yuan per set, and the maintenance is convenient. The total number of 9 boilers and 7 steam turbine generator units in a thermal power plant is that according to the requirements of DL/T246-2015 chemical supervision and guidance rules, the degassed hydrogen conductivity of 34 sample waters is monitored daily, a degassed hydrogen conductivity measuring device is purchased in the market, the cost is too high, the maintenance amount after installation is very large, and the cost can be saved by adopting the degassed hydrogen conductivity measuring device of the method: 5 ten thousand yuan/one set x 34 sets 170 ten thousand yuan. Other gas boilers and waste heat boilers are arranged in the horse steel company, and the method can be popularized and used for monitoring the conductivity of the degassed hydrogen and ensuring the safe and economic operation of the generator set.

Drawings

The contents of the expressions in the various figures of the present specification and the labels in the figures are briefly described as follows:

FIG. 1 is a schematic structural diagram of an on-line measuring device for pure water degassed hydrogen conductivity according to the present invention.

The labels in the above figures are:

1. h + type cation exchange column, 2, degassing column, 3, CO₂The device comprises an absorption pipe, 4, a conductivity cell, 5, a conductivity meter, 6, a water jet air ejector, 7, a rotor flow meter, 8, a packing layer, 9, an inlet pipe of circulating cooling water, 10, an outlet pipe of circulating cooling water, 11, sample water drainage, 12, a sample water inlet direction, 13, a water spraying nozzle, 14, an air inlet pipe, 15, an air inlet pipe, 16, a control valve, 17, a control water valve, 18, a water inlet pipe, 19 and a water outlet pipe.

Detailed Description

The following description of preferred embodiments of the invention will be made in further detail with reference to the accompanying drawings.

As shown in fig. 1, the online measurement method for pure water degassed hydrogen conductivity comprises the following specific steps:

(1) the sample water to be tested enters an H + type cation exchange column 1, and flows out after passing through the H + type cation exchange column 1;

(2) the effluent sample water enters a degassing column 2, the top of the degassing column 2 is connected with a water jet air extractor 6, the water jet air extractor 6 is communicated with the top end of the degassing column 2 through an air pipe, and a rotameter 7 is arranged on the air pipe; the degassing column 2 is internally provided with a packing layer 8 for dispersing water flow and increasing the contact area of a water film, sample water enters from the upper part of the packing layer 8 and passes through efficient CO₂The air treated by the absorbent enters from the lower part of the filler layer 8 under the action of the water jet air extractor 6; air entering from the lower part of the packing layer 8 contacts sample water sprayed from the upper part of the packing layer 8, and then CO in the water is discharged₂The analyzed water is discharged through a water jet air extractor 6;

(3) CO removal₂The sample water automatically flows into a conductivity cell 4, the conductivity cell 4 is a conductivity measurement flow cell, the water level of the sample water in the degassing column 2 is controlled by adjusting the height of an overflow port of the conductivity cell 4, a conductivity meter 5 is arranged in the conductivity cell 4, and the detected conductivity is the degassed hydrogen conductivity.

The determination of the electrical conductivity of the degassed hydrogen is generally applied to the boiler condensed water, feed water, steam and boiler water in a power plant, the water sample to be tested is provided with a circulating cooling device, part of the circulating cooling water is taken to form micro negative pressure in a degassing column 2 through a water jet air extractor 6, and CO is removed₂The air flows in the degassing column 2 and is easy to realize. The method can not only remove the carbon dioxide gas in the pure water more completely and ensure the accuracy of the conductivity measurement value of the degassed hydrogen, but also has simple equipment structure and convenient installation.

In the step (1), the inner diameter of the H + type cation exchange column 1 is 40mm-60mm, the height is 500-600mm, and the flow rate of the sample water to be detected is not less than 200 mL/min. The inner diameter of the H + type cation exchange column 1 is preferably 40mm, and the maximum is not more than 60 mm.

In the step (2), the inner diameter of the degassing column 2 is 1-1.5 times of that of the H + type cation exchange column 1, the height of the degassing column 2 is 500-600mm, the height of the packing layer 8 is not less than 300mm, and the specific surface area of the packing layer 8 is not less than 350m²/m³(ii) a The upper part of the packing layer 8 is provided with a water spraying nozzle 13 for sample water, and the lower part of the packing layer 8 is provided with an air inlet pipe 14.

The structural arrangement of the H + type cation exchange column 1 and the degassing column 2 realizes better removal of CO of the processed sample water clock to be detected₂The method has the advantages of being convenient for quickly and accurately measuring the electrical conductivity of the degassed hydrogen.

One end of an air inlet pipe 14 extends into the degassing column 2 and is arranged at the lower part of the packing layer 8, and the other end of the air inlet pipe 14 is provided with CO₂Absorption tube 3, CO₂The suction pipe 3 is connected to an air inlet pipe 15. Air is passed through the CO before entering the degassing column 2 from the air inlet pipe 14₂Efficient CO removal by absorber pipe 3₂To ensure that air CO is blown into the degassing column 2₂The content is minimum to ensure that CO in the sample water is removed₂The effect of (1).

CO₂The volume of the absorption tube 3 is not less than 200mL, CO₂The absorption pipe 3 is provided with CO₂An absorbent; CO 2₂The inlet and outlet of the absorption pipe 3 are connected by a hose, and the air inlet pipe 15 is provided with a control valve 16. The control valve 16 is used for controlling the inflow rate of air to ensure CO₂The absorption tube 3 can be removed to the maximum extent and enters the degassing column 2CO of air (1)₂。

Granular high-efficiency CO₂After absorption of the absorbent, CO in the air₂The concentration can be reduced to below 4 ppb. According to Henry's law, the CO in the sample water after the mass transfer of the air and the sample water in the degassing tower₂The concentration can be reduced to below 5ppb, and the degassing effect is better than that of the gas purging method (in nitrogen with the purity of more than 99.99 percent, CO in CO) specified in the pure water degassing hydrogen conductivity on-line measuring method of DL/T1602-2016 power plant₂At a concentration of less than 100 ppb). The method can obtain a degassed hydrogen conductivity detection value with higher accuracy.

And (3) arranging a temperature sensor in the conductivity cell 4, wherein the height of an overflow port of the conductivity cell 4 from the bottom of the degassing column 2 is 50-100 mm. The temperature sensor is used for measuring the temperature of the sample water in the conductivity cell and carrying out temperature compensation.

In the step (2), the water jet air ejector 6 is connected with the circulating cooling water, an inlet pipe 9 connected with the circulating cooling water and an outlet pipe 10 connected with the circulating cooling water are respectively connected with the water jet air ejector 6, and the inlet pipe 9 of the circulating cooling water is provided with a control water valve 17; the air extraction amount of the water jet air extractor 6 is 180L/h-360L/h; the negative pressure in the degassing column 2 is not more than 1-2 kPa. The water jet air ejector 6 is connected with an inlet pipe 9 of circulating cooling water and is additionally provided with a valve, and the air extraction amount is controlled to be about 180L/h-360L/h; or a plurality of degassing columns 2 can share one water jet air extractor 6, CO₂The air inlet pipe 15 of the absorption pipe 3 is provided with a control valve 16, the control valve 16 controls the air input of each degassing column 2 to be about 180L/h-360L/h, and the negative pressure in the columns is not more than 1-2 kPa.

As shown in FIG. 1, the device for on-line measurement of pure water degassed hydrogen conductivity is used for the above-mentioned method for on-line measurement of pure water degassed hydrogen conductivity, and comprises an H + type cation exchange column 1, a degassing column 2, and a conductivity cell 4 connected with the bottom end of the degassing column 2; the top end of the H + type cation exchange column 1 is connected with a water inlet pipe 18 communicated with sample water, and the bottom end of the H + type cation exchange column 1 is connected with a water outlet pipe 19; a packing layer 8 is arranged in the degassing column 2, and the top end of the degassing column 2 is connected with a water jet air extractor 6; the water outlet pipe 19 extends into the degassing column 2, and the outlet of the water outlet pipe 19 is positioned above the packing layer 8; an air inlet pipe 14 is connected to the side end of the degassing column 2, one end of the air inlet pipe 14 extends into the degassing column 2Is arranged below the packing layer 8, and the other end of the air inlet pipe 14 is connected with CO₂Absorption tube 3, CO₂The suction pipe 3 is connected to an air inlet pipe 15.

The operation steps of the online measuring device for the pure water degassing hydrogen conductivity are as follows: opening the water inlet valve of the sample water to be measured, adjusting the flow rate, and enabling the sample water to enter H in sequence⁺The type cation exchange column 1 and the degassing column 2 automatically flow into the conductance pool 4 and overflow; open high efficiency CO₂A control valve 16 for the air inlet 15 of the suction pipe 3; opening a control water valve 17 of a circulating cooling water inlet pipe 9 of the water jet air ejector 6, and adjusting the air input of the degassing column 2 to be about 180L/h-360L/h; and (3) putting a conductivity meter in the conductivity cell 4, and obtaining the conductivity of the degassed hydrogen when the measured value of the conductivity is reduced to be stable. The device is shut down and the reverse steps are followed.

The inner diameter of the H + type cation exchange column 1 is 40mm-60mm, the height is 500-600mm, and the flow of the sample water to be detected is not less than 200mL/min, so that the sample water entering the degassing column 2 can realize better degassing effect.

The inner diameter of the degassing column 2 is 1-1.5 times of that of the H + type cation exchange column 1, the height of the degassing column 2 is 500-600mm, the height of the packing layer 8 is not less than 300mm, and the specific surface area of the packing layer 8 is not less than 350m²/m³(ii) a The water outlet pipe 19 is provided with a sample water spraying nozzle 13.

The structural arrangement of the H + type cation exchange column 1 and the degassing column 2 realizes better removal of CO of the processed sample water clock to be detected₂The method has the advantages of being convenient for quickly and accurately measuring the electrical conductivity of the degassed hydrogen.

The degassed hydrogen conductivity measuring device adopting the method can accurately and rapidly measure the degassed hydrogen conductivity of pure water, and meanwhile, the cost is not more than 2 ten thousand yuan/set, and the device is convenient to maintain. Taking the current situation of the applicant as an example, the total number of 9 boilers and 7 steam turbine generator units in a thermal power plant is 9, according to the requirements of DL/T246-2015 chemical supervision and guidance, the degassed hydrogen conductivity of 34 sample waters is monitored daily, the degassed hydrogen conductivity measuring device purchased in the market has high cost and huge maintenance amount after installation, and the cost can be saved by adopting the degassed hydrogen conductivity measuring device prepared by the method: 5 ten thousand yuan/one set x 34 sets 170 ten thousand yuan. Other gas boilers and waste heat boilers are arranged in the horse steel company, and the method can be popularized and used for monitoring the conductivity of the degassed hydrogen and ensuring the safe and economic operation of the generator set. By adopting the invention, the production safety is improved, and the production cost is greatly reduced.

It is clear that the specific implementation of the invention is not restricted to the above-described embodiments, but that various insubstantial modifications of the inventive process concept and technical solutions are within the scope of protection of the invention.