CN214471626U

CN214471626U - System for monitoring condensate fine treatment mixed bed resin leakage in power plant

Info

Publication number: CN214471626U
Application number: CN202120431548.7U
Authority: CN
Inventors: 周潮; 刘宏侠; 白阳晨; 华若岚; 李强; 翟宏升; 高昆; 张倩玉
Original assignee: Datang Qinling Power Generation Co ltd
Current assignee: Datang Qinling Power Generation Co ltd
Priority date: 2021-02-26
Filing date: 2021-02-26
Publication date: 2021-10-22
Anticipated expiration: 2031-02-26

Abstract

The utility model provides a pair of power plant monitoring condensate polishing mixes bed resin leakage system, because OH type anion resin in the mixed bed resin begins to decompose when 60 ℃, produce benzyl alcohol, trimethylamine, amine ion and hydroxyl ion, after mixing the bed and throwing in, if mix the bed resin and leak, the resin is when low pressure feed water heater, low pressure feed water heater 7's operating temperature is 120 ℃, consequently OH type anion resin has decomposed, the hydroxyl ion in its product can make online conductivity table measurement value increase, consequently, the difference of the water conductivity that condenses after condensate according to oxygen-eliminating device entry condensate conductivity and the female pipe of mixed bed adds ammonia, can definitely know the mixed bed of throwing in and whether leak the resin, improve unit operation safety, also avoid the resin extravagant simultaneously.

Description

System for monitoring condensate fine treatment mixed bed resin leakage in power plant

Technical Field

The utility model relates to a power plant condensate water fine processing system, concretely relates to power plant monitoring condensate water fine processing mixes bed resin leakage system.

Background

The high-parameter and high-capacity generator set has more strict requirements on the quality of water vapor, the condensate polishing is an important measure for ensuring the quality of water vapor and the safe and economic operation of the generator set, the prior process of condensate polishing mainly comprises a mixed bed, and after resin of the mixed bed for condensate polishing leaks into a thermodynamic system, the safe operation of the generator set can be threatened, and particularly, the high-parameter and supercritical generator set with strict requirements on water quality has serious consequences. After the ion exchange resin enters the thermodynamic system, the ion exchange resin not only affects the quality of water vapor and increases water consumption and heat loss, but also severely corrodes the thermodynamic system to form a vicious circle. The boiler water runs at a low pH value for a long time, acid corrosion is formed, and hydrogen embrittlement occurs in serious cases, so that the boiler tube is exploded in a short time, and the safe running of the boiler is directly influenced. The quality of the boiler water is deteriorated, the steam carrying is increased, the quality of the steam is further influenced, the salt accumulation of the flow passage part of the superheater and the steam turbine is caused, the efficiency of the steam turbine is influenced, and the pipe explosion of the superheater can be caused in serious conditions. The distribution coefficient of acidic substances in the steam, such as sulfuric acid, formic acid and acetic acid, is very small, and particularly acidic corrosion can be caused to a steam turbine wet area, for example, a low-pressure section partition plate, a partition plate sleeve, a low-pressure cylinder inlet steam distribution device, a steam exhaust chamber and the like are corroded by the acid, so that a surface protective film of the low-pressure section partition plate falls off to form a corrosion groove, and the surface of the low-pressure section partition plate is rough and cellular, so that equipment is damaged.

In addition, because leaked resin can not be recycled after entering a thermodynamic system, great economic loss is caused, a series of adverse effects are caused on the operation and regeneration of the high-speed mixing bed, and the fine treatment operation level and reliability are seriously affected. Therefore, timely and accurate monitoring of mixed bed resin leakage is of great significance to safe operation of the unit. At present, the mixed bed resin leakage is mainly observed manually, and the timeliness is poor. When the mixed bed leaks the resin, the mixed bed leaks a large amount of resin, which causes great influence on the safe and economic operation of the unit.

SUMMERY OF THE UTILITY MODEL

In order to accurately find the mixed bed leakage resin in time, the utility model aims to provide a power plant monitoring condensate fine treatment mixed bed resin leakage system and method, can effectively accurately monitor the mixed bed leakage tree in time.

The utility model discloses a realize through following technical scheme:

a system for monitoring condensate fine treatment mixed bed resin leakage of a power plant comprises a controller, a mixed bed main pipe conductivity meter connected with the controller, a deaerator inlet conductivity meter and an electric valve;

the mixed bed main pipe electric conductivity meter is arranged on a pipeline after ammonia is added into the mixed bed main pipe, the deaerator inlet electric conductivity meter is arranged on a deaerator inlet main pipe, the deaerator inlet main pipe is connected with an outlet of a heater, and an inlet of the heater is connected with the mixed bed main pipe;

the controller is used for outputting an alarm signal of the mixed bed leaked resin according to the detection data of the mixed bed main pipe conductivity meter and the deaerator inlet conductivity meter.

Preferably, an electric valve is arranged on an outlet pipeline of the mixing bed and connected with a controller, and the controller is used for acquiring a valve position signal of the electric valve and determining a serial number of the mixing bed to be put into operation.

Preferably, when a plurality of mixing beds are included, an electric valve is arranged at the outlet of each mixing bed.

Preferably, the number of the mixed beds is three, and the three mixed beds are all connected with the mixed bed main pipe.

Preferably, the heater is a low pressure heater.

Preferably, the controller is a PLC.

Compared with the prior art, the utility model discloses following profitable technological effect has:

the utility model provides a pair of power plant monitoring condensate polishing mixes bed resin leakage method, because OH type anion resin in the mixed bed resin begins to decompose when 60 ℃, produce benzyl alcohol, trimethylamine, amine ion and hydroxyl ion, after mixing the bed and throwing in, if mix the bed and leak the resin, the resin is when low pressure feed water heater, low pressure feed water heater's operating temperature is 120 ℃, consequently OH type anion resin has decomposed, the hydroxyl ion in its product can make online conductivity table measurement value increase, consequently, according to the oxygen-eliminating device entry conductivity with mix the difference of bed total export postammoniation conductivity, can clearly know the mixed bed of throwing in whether leak the resin, improve unit operation security, also avoid the resin extravagant simultaneously.

Drawings

Fig. 1 is a schematic diagram of the control system of the present invention.

Fig. 2 is a historical curve diagram of the electric conductivity of the oxygen remover inlet and the mixed bed total outlet after ammonia addition in embodiment 1 of the present invention.

In the figure: 1. the device comprises a mixed bed main pipe conductivity meter, 2, a deaerator inlet conductivity meter, 3, a first electric valve, 4, a second electric valve, 5, a third electric valve, 6, a mixed bed main pipe, 7, a low-pressure heater, 8, a deaerator inlet main pipe, 9 and a controller.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings, which are provided for purposes of illustration and not limitation.

Referring to fig. 1 and 2, a system for monitoring condensate polishing mixed bed resin leakage in a power plant comprises a controller 9, and a mixed bed main pipe conductivity meter 1, a deaerator inlet conductivity meter 2, a first electric valve 3, a second electric valve 4 and a third electric valve 5 which are connected with the controller.

The mixed bed main pipe electric conductivity meter 1 is arranged on a pipeline after ammonia is added into the mixed bed main pipe 6, the deaerator inlet electric conductivity meter 2 is arranged on a deaerator inlet main pipe 8, the first electric valve 3 is arranged on an outlet pipeline of the mixed bed A, the second electric valve 4 is arranged on an outlet pipeline of the mixed bed B, and the third electric valve 5 is arranged on an outlet pipeline of the mixed bed C.

The deaerator inlet main pipe 8 is connected with the outlet of the low-pressure heater 7, and the inlet of the low-pressure heater 7 is connected with the mixed bed main pipe 6.

The controller 9 is used for receiving detection data of the mixed bed main pipe electric conductivity meter 1 and the deaerator inlet electric conductivity meter 2 and opening and closing signals of the first electric valve 3, the second electric valve 4 and the third electric valve 5.

The controller is a PLC or an industrial personal computer.

The monitoring method for monitoring the condensate polishing mixed bed resin leakage system of the power plant comprises the following steps:

step 1, determining a serial number of a mixed bed to be put into operation according to a valve position signal of an electric valve of the mixed bed;

step 2, obtaining the conductivity average value delta of condensed water after ammonia is added into the mixed bed main pipe in a set time before the mixed bed is put into operation_{1 front}And the average value delta of the conductivity of the condensate at the inlet of the deaerator_{2 front}And calculating the difference delta between the two_{Front side}；

Specifically, the conductivity meter of the mixed bed main pipe and the conductivity meter of the deaerator inlet are measured in real time on line, and measured data are sent to the controller to be recorded simultaneously.

Therefore, in a set time range before the mixed bed is put into operation, the average value of the conductivity kappa of the condensed water after the ammonia is added in the mixed bed main pipe in the set time range can be obtained through historical measurement data_{1 front}And average value of conductivity k of condensed water at the inlet of deaerator_{2 front}。

Average value of conductivity κ_{2 front}And conductivity mean value k_{1 front}Difference value delta of_{Front side}The calculation method of (2) is as follows:

δ_{front side}＝κ_{2 front}-κ_{1 front}

Step 3, obtaining the conductivity average value kappa of condensed water after ammonia is added to the mixed bed main pipe in the set time after the mixed bed is put into operation_{1 after}And average value of conductivity k of condensed water at the inlet of deaerator_{2 after}And calculating the difference delta between the two_{Rear end}；

Average value of conductivity κ_{2 after}And electrical conductivityMean value kappa_{2 after}Difference value delta of_{Rear end}The calculation method of (2) is as follows:

δ_{rear end}＝κ_{2 after}-κ_{1 after}

Step 4, calculating the difference delta_{Rear end}And the difference delta before delta, the calculation method is as follows:

δ＝δ_{rear end}-δ_{Front side}

And when delta is larger than the set threshold value, outputting an alarm signal of the mixed bed resin leakage in the step 1.

The utility model discloses monitoring method's theory of operation as follows:

the resins in the mixed bed include: a negative resin and a positive resin.

The cation resin begins to decompose at 150 ℃ into sulfuric acid and sodium bisulfate.

The anion resin is mostly OH type and Cl type.

The OH type anion resin starts to decompose into benzyl alcohol, trimethylamine, amine ions and hydroxide ions at 60 ℃.

The Cl-type anion resin starts to decompose into benzyl chloride, trimethylamine, benzyl alcohol and amine chloride at 160 ℃.

When the mixed bed is put into operation, if the mixed bed resin leaks, when the resin passes through the low-pressure heater 7, because the working temperature of the low-pressure heater 7 is 120 ℃, only OH type negative resin is decomposed, and the decomposition products are as follows: methanol, trimethylamine, amine ions and hydroxide ions, wherein the hydroxide ions increase the measured value of the deaerator inlet conductivity meter 2. When the leaked resin does not enter the low-pressure heater 7, the working temperature is lower than 60 ℃, the cation and anion resin can not be decomposed, and the change of the measurement value of the mixed bed main pipe conductivity meter 1 can not be caused.

And the controller 9 determines the mixed bed leakage resin according to the fact that the difference value of the measured values of the mixed bed main pipe conductivity meter 1 and the deaerator inlet conductivity meter 2 in a certain time is larger than a preset value, and alarm of mixed bed resin leakage through condensate fine treatment is achieved.

Example 1

Taking a 600MW supercritical DC furnace unit of a certain power plant as an example, after a mixed bed is put into operation, the historical curve of the electric conductivity of the inlet of the deaerator and the electric conductivity of the total outlet of the mixed bed after ammonia addition is shown in figure 1, and it can be seen that the electric conductivity of the inlet of the deaerator and the electric conductivity of the total outlet of the mixed bed after ammonia addition have obvious difference. Before the mixed bed is put into operation, the average value of the electric conductivity of the inlet of the deaerator is 5.83 mu S/cm, the average value of the electric conductivity of the total outlet of the mixed bed after ammonia is added is 5.81 mu S/cm, and the electric conductivity is not changed. The average value of the conductivity of the inlet of the deaerator after the mixed bed is put into operation is 6.12 mu S/cm, the average value of the conductivity of the total outlet of the mixed bed after ammonia is added is 5.81 mu S/cm, and the average value of the conductivity is increased by 0.31 mu S/cm. Upon manual observation, leaked resin was found.

The above contents are only for explaining the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby, and any modification made on the basis of the technical solution according to the technical idea of the present invention all fall within the protection scope of the claims of the present invention.

Claims

1. A system for monitoring condensate polishing mixed bed resin leakage in a power plant is characterized by comprising a controller (9), a mixed bed main pipe conductivity meter (1), a deaerator inlet conductivity meter (2) and an electric valve, wherein the mixed bed main pipe conductivity meter, the deaerator inlet conductivity meter and the electric valve are connected with the controller;

the mixed bed main pipe conductivity meter (1) is arranged on a pipeline after ammonia is added into the mixed bed main pipe (6), the deaerator inlet conductivity meter (2) is arranged on a deaerator inlet main pipe (8), the deaerator inlet main pipe (8) is connected with an outlet of a heater, and an inlet of the heater is connected with the mixed bed main pipe (6);

and the controller (9) is used for outputting an alarm signal of the mixed bed leakage resin according to the detection data of the mixed bed main pipe conductivity meter (1) and the deaerator inlet conductivity meter (2).

2. The system for monitoring the resin leakage of the condensate polishing mixed bed in the power plant as claimed in claim 1, wherein an electric valve is arranged on an outlet pipeline of the mixed bed, the electric valve is connected with a controller, and the controller is used for acquiring a valve position signal of the electric valve and determining a serial number of the mixed bed in operation.

3. The system of claim 1, wherein when a plurality of mixed beds are included, an electrically operated valve is provided at the outlet of each mixed bed.

4. The system for monitoring the condensate polishing mixed bed resin leakage in the power plant according to claim 3, wherein the number of the mixed beds is three, and the three mixed beds are all connected with a mixed bed main pipe.

5. The system of claim 1, wherein the heater is a low pressure heater.

6. The system of claim 1, wherein the controller is a PLC.