CN115541485A - A thermal power plant shutdown protective agent maintenance effect evaluation device and using method - Google Patents

Abstract

The invention discloses a maintenance effect evaluation device and a method for using a thermal power plant shutdown protective agent. ; The outlet of the humidifier is connected to the regulating chamber, the regulating chamber is equipped with a cooler and a heater, the regulating chamber is equipped with a first temperature and humidity meter, the inlet of the circulating fan is connected to the regulating chamber, and the outlet of the circulating fan is connected to The inlet of the dryer and its bypass, the outlet of the dryer and its bypass are connected to the test piece suspension device and the inlet of the bypass, the outlet pipe of the test piece suspension device and the bypass is connected to the second temperature and humidity meter and connected to the conditioning room . The operation of the evaluation device is controlled by PLC, and the surface state of the test piece can be observed in real time under the set temperature and humidity. The invention is suitable for evaluating the maintenance effect of the shutdown protection agent in thermal power plants.

Description

A thermal power plant shutdown protective agent maintenance effect evaluation device and using method

technical field

The invention belongs to the field of outage maintenance of thermal equipment, and in particular relates to a maintenance effect evaluation device and a use method of a furnace outage protective agent in a thermal power plant.

Background technique

When the boiler in a thermal power plant is in standby, the oxygen and moisture in the air will cause oxygen corrosion on the heating surface of the boiler. The corrosion of the boiler in the thermal power plant during the stand-by period can lead to poor water vapor quality when the boiler is restarted. Startup requires a lot of cold and hot flushing, resulting in waste of water and energy, and can cause damage to the metal structure of the inner surface of the boiler. This will affect the service life of the boiler. Carrying out shutdown maintenance on boilers that have been shut down for standby use can effectively suppress downtime corrosion. Commonly used furnace shutdown maintenance methods include nitrogen filling maintenance, hot furnace water discharge waste heat drying, dry air drying method, ammonia-hydrazine method, furnace shutdown protection agent maintenance, etc. Because of the advantages of good maintenance effect, no need for special dosing equipment, and simple dosing operation, the maintenance of boiler shutdown protection agent is widely used in shutdown maintenance of thermal power plants in my country.

The electric power industry standard DL/T 956-2017 "Guidelines for Anti-corrosion of Thermal Equipment for Shutdown (Standby) in Thermal Power Plants" stipulates that when using new organic amine alkalizers and corrosion inhibitors for outage maintenance, it should be determined through tests Drug concentration and process parameters to avoid corrosion and pollution of thermal equipment due to excessive drug or decomposition products. However, DL/T 956-2017 does not provide a method for evaluating the maintenance effect of the shutdown protective agent.

GB/T 25149-2010 "Red point method for testing the quality of carbon steel passivation film in chemical cleaning of industrial equipment" gives the quality method of chemical cleaning carbon steel passivation film. In this method, the carbon steel surface is chemically cleaned by acidic copper sulfate dripping, and the quality of the passivation film is determined according to the discoloration time of the copper sulfate dripping liquid. This method can test the quality of the passivation film, but it cannot directly determine the effect of the shutdown protection agent on the shutdown maintenance of thermal power plants and the maintenance time limit.

Contents of the invention

In order to better evaluate the effectiveness and timeliness of maintenance of thermal power plant shutdown protection agents, the purpose of the present invention is to provide a thermal power plant shutdown protection agent maintenance effect evaluation device and method of use, the method of the invention is easy to implement , high reliability of the device, good uniformity of temperature and humidity in the dynamic operation of the system, the timeliness of the shutdown protective agent can be evaluated, and the corrosion status of the test piece can be observed in real time.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A maintenance effect evaluation device for a thermal power plant shutdown protection agent, including a regulating chamber, a humidifier, a circulating fan, a dryer and its bypass, a test piece suspension device and the bypass;

The outlet of the humidifier is connected to the regulating chamber, the regulating chamber is equipped with a cooler and a heater, the regulating chamber is equipped with a first temperature and humidity meter, the inlet of the circulating fan is connected to the regulating chamber, and the outlet of the circulating fan is connected to the drying chamber. The inlet of the dryer and its bypass, the outlet of the dryer and its bypass are connected to the test piece suspension device and the inlet of the bypass, and the outlet pipeline of the test piece suspension device and the bypass is connected to the second temperature and humidity meter and connected to the adjustment room.

As a further improvement of the present invention, the top of the regulating chamber is provided with an electric intake valve, and the bottom of the regulating chamber is provided with an electric discharge valve.

As a further improvement of the present invention, the humidifier is an ultrasonic humidifier, and a thermostatic device with adjustable temperature is installed inside. The humidifier is connected with an isolated electric valve and connected to the regulating chamber.

As a further improvement of the present invention, the heater is an electric heating wire heater, and the heating system has an over-temperature alarm.

As a further improvement of the present invention, the desiccator and its bypass include at least one main path of the drier and one bypass of the drier, and the desiccant is equipped with a color-changing silica gel desiccant.

As a further improvement of the present invention, the test piece suspension device and bypass include at least one test piece suspension device and one bypass, and the material of the test piece suspension device is transparent material; there is a flow meter and an isolation valve in front of the test piece suspension device , An isolation valve is installed behind the test piece suspension pipe; an electric valve is installed in the bypass of the test piece suspension device.

As a further improvement of the present invention, it also includes PLC, the intake electric valve and discharge electric valve on the regulating chamber, humidifier, cooler, heater, circulating fan, dryer and the main circuit electric valve on the bypass And the bypass electric valve, the test piece suspension device and the bypass valve on the bypass are all electrically connected to the PLC.

A method for using a maintenance effect evaluation device for a thermal power plant shutdown protection agent, characterized in that it includes:

Hang the test pieces in the autoclave that have undergone protection and maintenance tests into the test piece suspension device and the bypass test piece suspension device, open the inlet and outlet valves of the test piece suspension device, close the bypass door, and start the test. During the test, the system Maintain the set temperature and humidity, the control range is 0-45°C, and the humidity control range is 10%-96%;

During the operation of the evaluation device, observe the corrosion of the test piece under the set temperature and humidity.

As a further improvement of the present invention, the test piece through the protection and maintenance test in the autoclave is hung into the test piece suspension device and the bypass test piece suspension device, which also includes before:

Start the humidifier, cooler, and humidifier. When the temperature and humidity of the first thermo-hygrometer reach the set value, the circulation fan will be put into operation, and the bypass valve of the dryer and its bypass will be opened at the same time, and the dryer and its bypass will be closed. At the same time, open the test piece suspension device and the bypass of the bypass and manually close the main circuit. In the first stage, if the system humidity is high, the cooler will dehumidify it, and it will end when the second temperature and humidity reach the set value.

As a further improvement of the present invention, the test piece through the protection and maintenance test in the autoclave is hung into the test piece suspension device and the bypass test piece suspension device, specifically:

The liquid phase test piece, the vapor phase test piece and the vapor-liquid two-phase test piece in the autoclave are respectively hung in three separate test piece suspension devices.

Compared with the prior art, the present invention has the following advantages:

The maintenance effect evaluation device of the furnace shutdown protection agent of the present invention is simple in structure, easy to realize, automatic control of temperature and humidity, flexible and can operate dynamically. The test piece can be tested on the test piece suspension device and the test piece in the bypass, and the environment can be simulated by observing the temperature and humidity through the first thermo-hygrometer and the second thermo-hygrometer, and the surface of the test piece can be observed in real time under the set temperature and humidity state. The device can evaluate the timeliness of the furnace shutdown protective agent, and can evaluate the effects of various shutdown protections such as film-forming amines and active amines. During the evaluation process, the corrosion of the test piece can be observed in real time. Therefore, it is of great significance to develop an evaluation device suitable for evaluating the maintenance effect of shutdown protection agents, which can effectively screen shutdown protection agents and determine the maintenance timeliness of shutdown protection agents, which is of great significance to ensure the normal operation of boilers in thermal power plants.

Description of drawings

Fig. 1 is a schematic diagram of a thermal power plant shutdown protection agent maintenance effect evaluation device of the present invention.

detailed description

In order to enable those skilled in the art to understand the features and effects of the present invention, the terms and terms mentioned in the specification and claims are generally described and defined below. Unless otherwise specified, all technical and scientific terms used herein have the usual meanings understood by those skilled in the art for the present invention. In case of conflict, the definitions in this specification shall prevail.

The theories or mechanisms described and disclosed herein, whether true or false, should not limit the scope of the present invention in any way, ie, the present invention can be practiced without being limited by any particular theory or mechanism.

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

As shown in Fig. 1, the present invention provides a kind of thermal power plant shut-down protection agent maintenance effect evaluation device, comprises adjustment room 1, humidifier 2, cooler 3, heater 4, first temperature-hygrometer 5, circulating fan 6. Desiccator and its bypass 7. Test piece suspension device and bypass 8. Second temperature and humidity meter 9.

The outlet of the humidifier 2 is connected to the regulating chamber 1, the cooler 3 and the heater 4 are built in the regulating chamber 1, the top of the regulating chamber 1 is equipped with a first temperature-hygrometer 5, and the inlet of the circulating fan 6 is connected to the regulating chamber 1 , the outlet of the circulating fan 6 is connected to the inlet of the dryer and its bypass 7, the outlet of the dryer and its bypass 7 is connected to the entrance of the test piece suspension device and the bypass 8, and the outlet of the test piece suspension device and the bypass 8 The second hygrometer 9 is connected to the pipeline and connected to the conditioning chamber 1 .

The device can evaluate the timeliness of the furnace shutdown protective agent, and can evaluate the effects of various shutdown protections such as film-forming amines and active amines. During the evaluation process, the corrosion of the test piece can be observed in real time.

The functions and details of each part are as follows:

The regulating chamber 1 has the function of regulating the temperature and humidity of the system. The top of the regulating chamber 1 is provided with an electric intake valve, and the bottom of the regulating chamber 1 is provided with an electric discharge valve.

The humidifier 2 is an ultrasonic humidifying device with a constant temperature device inside, and the temperature can be set. The humidifier 2 is connected with an isolated electric valve and connected to the regulating chamber 1. The humidified particles ejected by the humidifier 2 are gas The particle size of aerosol and aerosol is less than 50μm, and the humidifier 2 can keep the maximum relative humidity of the system to 96%.

The heater 4 is an electric heating wire heater, the heating system has an over-temperature alarm, and the heater 4 can heat the maximum temperature of the system to 45°C.

The cooler 3 has two functions, one is to cool down the system when the system temperature exceeds the set temperature, and the other is to condense the water vapor to achieve the purpose of dehumidification when the system humidity exceeds the set humidity. The cooler 3 can Lower the system temperature to a minimum of 0 °C.

The dryer and its bypass 7 are the main road of the two-way dryer and the bypass of the one-way dryer. The dryer is equipped with a color-changing silica gel desiccant. When the system is running, the humidity can be fine-tuned. The adjustment method is: turn off the bypass, Slightly open the desiccant one way, and the other desiccant for spare. When the system is running, if the system does not need to adjust the humidity, the bypass of the dryer is put into operation. The main road of the dryer is equipped with electric valves before and after the dryer, and the bypass valve of the dryer is also an electric valve.

Described test piece suspension device and bypass 8 are three-way test piece suspension device and one-way bypass, and the material of three-way test piece suspension device is transparent material, for example, glass or plexiglass, and the purpose of suspension tube material is transparent material In order to monitor the corrosion of the surface of the test piece in real time during the operation of the device. There are flowmeters and isolation valves in front of the test piece suspension pipe, and an isolation valve is also installed behind the test piece suspension pipe. The bypass of the test piece suspension device is equipped with an electric valve. When the maintenance effect evaluation device is in the temperature and humidity adjustment stage, the bypass of the test piece suspension device is put into operation. When the temperature and humidity reach the set value, the test piece is hung into the suspension pipe and the flow rate of the test piece suspension device is adjusted to the required flow rate. Close the bypass to the test strip suspension.

The intake electric valve and discharge electric valve on the regulating chamber 1, humidifier 2, cooler 3, heater 47, circulation fan 6, dryer and the main road electric valve and bypass electric valve on the bypass 7 The valve, the test piece suspension device and the bypass electric valve on the bypass 8 are all electrically connected to the PLC, and the PLC is equipped with a digital display control panel for system parameter input.

The second object of the present invention is to provide a method for using a thermal power plant shutdown protective agent maintenance effect evaluation device. The operation of the evaluation device includes two stages:

The first stage is the constant temperature and humidity adjustment stage. In the first stage, the humidifier 2, cooler 3, and humidifier 24 are controlled by the PLC according to the temperature and humidity set by the PCL control panel. The control strategy is PID control. When the first temperature and humidity meter 5, after the temperature and humidity reach the set value, put into operation the circulation fan 6, open the bypass valve of the drier and its bypass 7 at the same time, close the main valve of the drier and its bypass 7, and open the test piece suspension device and Bypass 8 and manually close its main circuit. In the first stage, if the system humidity is high, the cooler 3 will dehumidify it. When the second temperature and humidity reach the set value, the first stage ends;

The second stage is the evaluation stage. First, hang the test pieces in the autoclave that have passed the maintenance test into the test piece suspension device and the test piece suspension device of the bypass 8. The liquid phase test piece, the vapor phase test piece and the vapor-liquid two The relative test piece can be hung on three separate test piece suspension devices, open the inlet and outlet valves of the test piece suspension device, close its bypass door, and start the test. During the test, the system maintains the set temperature and humidity, in order to prevent control In the process of temperature control and humidity, the humidity and the set value are too high to prevent temperature fluctuations during dehumidification. In the second stage of dehumidification, open the main valve of the dryer and its bypass 7 (do not use the cooler 3 for dehumidification) and use the dryer to dehumidify , The temperature control and humidity control of the second stage are controlled by PCL. The temperature control accuracy of the two-stage PLC is ±1°C, and the humidity control accuracy is ±3%. The temperature control range of the invention is 0-45 DEG C, and the humidity control range is 10%-96%. During the operation of the evaluation device, the corrosion of the test piece under the set temperature and humidity can be observed to determine the maintenance effect of the shutdown protective agent.

Conventional instruments and equipment in the art are used in the following examples. For the experimental methods without specific conditions indicated in the following examples, the conventional conditions or the conditions suggested by the manufacturer are usually followed. Various raw materials are used in the following examples. Unless otherwise specified, conventional commercially available products are used, and their specifications are conventional specifications in the art.

Example 1:

The protective effect of the modified octadecylamine shutdown protection agent intended to be used in the maintenance of 300WM boilers was evaluated. Liquid plate. After the film-forming test is completed, the effect evaluation is carried out. The evaluation device used is as follows: the outlet of the humidifier 2 is connected to the adjustment chamber 1, the cooler 3 and the heater 4 are built in the adjustment chamber 1, and the first temperature-hygrometer is installed on the top of the adjustment chamber 1 5. The inlet of the circulation fan 6 is connected to the adjustment chamber 1, the outlet of the circulation fan 6 is connected to the inlet of the dryer and its bypass 7, and the outlet of the dryer and its bypass 7 is connected to the test piece suspension device and the outlet of the bypass 8 The inlet, the test piece suspension device and the outlet pipeline of the bypass 8 are connected to the second temperature-hygrometer 9 and connected to the conditioning chamber 1 . The top of the regulating chamber 1 is provided with an electric intake valve, and the bottom of the regulating chamber 1 is provided with an electric discharge valve. An electric valve is connected between the humidifier and the regulating chamber 1 . There are two main roads of the dryer, electric valves are installed before and after the desiccant, and the bypass of the dryer is also an electric valve. The three main paths of the test piece suspension device are manual valves, and the bypasses of the test piece suspension device are electric valves. The humidifier 2, the cooler 3, the heater 4, the circulation fan 6, the first temperature-hygrometer 5, the second temperature-hygrometer 9 and the electric valves of the system are all electrically connected to the PLC. Set the temperature on the PLC control panel to 25°C and the relative humidity to 80%, start the first-stage program operation, and the system will circulate constant temperature and humidity. When the temperature of the second thermo-hygrometer 9 reaches 25±1°C, the relative humidity is 80%±3 % when the first phase ends. Hang the liquid phase test piece, vapor phase test piece and vapor-liquid phase test piece into the test piece suspension device respectively, start the second stage program, manually adjust the flow rate of the test piece suspension device to 0.5m ³ /h, and maintain the system temperature at 25± 1°C, relative humidity 80%±3%. After that, check the corrosion condition of the test piece every 12 hours, and record the time when the test piece begins to corrode, so as to determine the protective effect of the modified octadecylamine shutdown protective agent.

Example 2:

Evaluate the protective effect of the active organic amine shutdown protection agent to be applied to the 300WM boiler maintenance. The film formation test of the shutdown protection agent is carried out in an autoclave, and the liquid phase suspension, vapor phase suspension and vapor-liquid phase suspension are respectively carried out. piece. After the film-forming test is completed, the effect evaluation is carried out. The evaluation device used is as follows: the outlet of the humidifier 2 is connected to the adjustment chamber 1, the cooler 3 and the heater 4 are built in the adjustment chamber 1, and the first temperature-hygrometer is installed on the top of the adjustment chamber 1 5. The inlet of the circulation fan 6 is connected to the adjustment chamber 1, the outlet of the circulation fan 6 is connected to the inlet of the dryer and its bypass 7, and the outlet of the dryer and its bypass 7 is connected to the test piece suspension device and the outlet of the bypass 8 The inlet, the test piece suspension device and the outlet pipeline of the bypass 8 are connected to the second temperature-hygrometer 9 and connected to the conditioning chamber 1 . The top of the regulating chamber 1 is provided with an electric intake valve, and the bottom of the regulating chamber 1 is provided with an electric discharge valve. An electric valve is connected between the humidifier and the regulating chamber 1 . There are two main roads of the dryer, electric valves are installed before and after the desiccant, and the bypass of the dryer is also an electric valve. The three main paths of the test piece suspension device are manual valves, and the bypasses of the test piece suspension device are electric valves. The difference from Embodiment 1 is that the second hygrometer is connected to a tee, one end of the tee is connected to the electric valve and then connected to the regulating chamber 1, the other end of the three is connected to the electric valve, and the other end of the electric valve is facing the air. The humidifier 2, the cooler 3, the heater 4, the circulation fan 6, the first temperature-hygrometer 5, the second temperature-hygrometer 9 and the electric valves of the system are all electrically connected to the PLC. Set the temperature on the PLC control panel to 30°C and the relative humidity to 75%, start the first-stage program operation, and the system will perform constant temperature and humidity. When the system temperature does not reach 30±1°C and the relative humidity does not reach 75%±3%, the system will The gas in the constant temperature and humidity process does not return to the conditioning chamber 1, and is discharged to the air. When the temperature of the second thermo-hygrometer 9 reaches 30±1° C. and the relative humidity is 75%±3%, the system switches to circulation, and the first stage ends. Hang the liquid phase test piece, vapor phase test piece and vapor-liquid phase test piece into the test piece suspension device respectively, start the second stage program, manually adjust the flow rate of the test piece suspension device to 0.6m ³ /h, and maintain the system temperature at 30± 1°C, relative humidity 75%±3%. After that, check the corrosion condition of the test piece every 12 hours, and record the time when the test piece begins to corrode, so as to determine the protective effect of the modified active organic amine protective agent.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be It is regarded as the protection scope of the present invention.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (10)

1. A thermal power plant shutdown protection agent maintenance effect evaluation device is characterized in that it comprises a conditioning chamber (1), a humidifier (2), a circulating fan (6), a drier and its bypass (7) and a test chamber Sheet suspension device and bypass (8); The outlet of the humidifier (2) is connected to the regulating chamber (1), the regulating chamber (1) is equipped with a cooler (3) and a heater (4), and the regulating chamber (1) is equipped with a first temperature and humidity Meter (5), the inlet of the circulation fan (6) is connected to the regulating chamber (1), the outlet of the circulation fan (6) is connected to the inlet of the dryer and its bypass (7), and the dryer and its bypass (7) The outlet is connected to the inlet of the test piece suspension device and the bypass (8), and the outlet pipeline of the test piece suspension device and the bypass (8) is connected to the second temperature-hygrometer (9) and connected to the regulating chamber (1). 2. The thermal power plant shutdown protection agent maintenance effect evaluation device according to claim 1, characterized in that, the top of the regulating chamber (1) is provided with an electric intake valve, and the bottom of the regulating chamber (1) is provided with an electric discharge valve . 3. The thermal power plant shutdown protective agent maintenance effect evaluation device according to claim 1, characterized in that, the humidifier (2) is an ultrasonic humidifier, and a thermostatic device with adjustable temperature is arranged inside it to humidify The device (2) is connected with an isolation electric valve and connected to the regulating chamber (1). 4. The thermal power plant shutdown protective agent maintenance effect evaluation device according to claim 1, characterized in that, the heater (4) is an electric heating wire heater, and the heating system has an over-temperature alarm. 5. The thermal power plant shutdown protective agent maintenance effect evaluation device according to claim 1, characterized in that, said drier and its bypass (7) at least include a main road of a drier and a bypass of a drier. Road, the desiccator is equipped with a color-changing silica gel desiccant. 6. The thermal power plant shutdown protective agent maintenance effect evaluation device according to claim 1, characterized in that, said test piece suspension device and bypass (8) at least comprise one test piece suspension device and one road bypass, The material of the test piece suspension device is transparent material; there is a flow meter and an isolation valve in front of the test piece suspension device, and an isolation valve is installed behind the test piece suspension pipe; the bypass of the test piece suspension device is equipped with an electric valve. 7. The thermal power plant shutdown protection agent maintenance effect evaluation device according to claim 1, characterized in that it also includes PLC, the intake electric valve and discharge electric valve, humidifier on the control chamber (1) (2), cooler (3), heater (7), circulation fan (6), main circuit electric valve and bypass electric valve on the dryer and its bypass (7), test piece suspension device and bypass (8) The bypass valves on (8) are all electrically connected to the PLC. 8. A method for using the thermal power plant shutdown protective agent maintenance effect evaluation device as described in any one of claims 1 to 7, characterized in that it comprises: Hang the test pieces in the autoclave that have undergone protection and maintenance tests into the test piece suspension device and the test piece suspension device of the bypass (8), open the inlet and outlet valves of the test piece suspension device, close the bypass door, and start the test. During the process, the system maintains the set temperature and humidity, the control range is 0-45°C, and the humidity control range is 10%-96%; During the operation of the evaluation device, observe the corrosion of the test piece under the set temperature and humidity. 9. using method according to claim 8, it is characterized in that, the test piece through protection and maintenance test in autoclave is hung in the test piece suspension device of test piece suspension device and bypass (8), also comprises before: Start the humidifier (2), cooler (3), and humidifier (4), and when the temperature and humidity of the first thermo-hygrometer (5) reach the set value, put into operation the circulation fan (6), and simultaneously open the dryer and The bypass valve of its bypass (7) and close the main road valve of the drier and its bypass (7), open the test piece suspension device and the bypass of bypass (8) at the same time and manually close its main road, the first In the stage, if the system humidity is high, dehumidification is carried out by the cooler (3), and ends when the second temperature and humidity (9) reaches the set value. 10. using method according to claim 8, it is characterized in that, the test piece through protection and maintenance test in the autoclave is hung in the test piece suspension device of test piece suspension device and bypass (8), specifically: The liquid phase test piece, the vapor phase test piece and the vapor-liquid two-phase test piece in the autoclave are respectively hung in three separate test piece suspension devices.

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