Waste oil atomization combustion-increasing device of CFB boiler

Abstract

The utility model discloses a waste oil atomization combustion-increasing device of a CFB boiler. The waste oil atomization combustion-increasing device comprises a waste oil purification device, a fuel oil device, an atomization device, a secondary atomization pipeline, a starting combustor and a DCS control system. According to the CFB boiler starting burner, the function that the CFB boiler starting burner can burn fuel oil is utilized, waste oil is firstly treated and atomized, meanwhile, the Venturi tube is utilized to atomize the fuel oil and mix the fuel oil with the atomized waste oil, and therefore atomized mixed oil mist with a high calorific value is formed to be burnt in the starting burner, contact with pulverized coal is avoided, and the combustion efficiency is improved. And the effects of increasing combustion and reducing fuel consumption are achieved for boiler combustion.

Description

TECHNICAL FIELD

[0001] The utility model relates to the auxiliary equipment of boiler combustion production with thermal power plant lubricating oil etc. BACKGROUND

[0002] The circulating fluidized bed boiler (CFB) power station rotating machine is more, and a large number of lubricating oils are used for lubrication. The waste lubricating oil replaced after maintenance is generally handed over to a special recycling unit for processing, and the thermal power plant will pay a considerable disposal fee. In order to make full use of the waste oil, some thermal power plants use the method of directly atomizing and spraying the lubricating oil into the coal-fired boiler for combustion, but there are the following problems: 1) the waste oil composition is complex, and after atomization, it may exacerbate the ash coking problem mixed with the boiler coal powder; 2) if it is sprayed from a certain part of the boiler, improper design or operation may also cause the coal powder to deviate from the ignition point.

[0003] Therefore, it is urgent to develop a waste oil atomization combustion device for CFB boiler to ensure the atomization effect. SUMMARY

[0004] The technical problem to be solved by the present application is that the existing method of waste oil entering the boiler for combustion may exacerbate the ash coking problem and cause the coal powder to deviate from the ignition point.

[0005] To solve the above technical problems, the present application provides a waste oil atomization combustion device for CFB boiler, which comprises: a waste oil purification device comprising a waste oil purifier, an oil filter screen, an oil pump and an ultrasonic oil atomizer connected in sequence on a pipeline, the waste oil purifier is connected to a waste oil treatment device of a power plant, and the outlet end of the ultrasonic oil atomizer is connected to the throat of a Venturi atomizer through a pipeline, and an oil atomizer outlet electric regulating valve is arranged on the pipeline; a fuel device comprising a fuel pressure regulating valve, a shut-off valve and an electric regulating valve connected in sequence on a pipeline, the inlet end of the fuel pressure regulating valve is connected to a fuel storage device, and the outlet end of the electric regulating valve is connected to the negative pressure area of the throat of the Venturi atomizer through a pipeline; an atomization device comprising a first pipeline and a second pipeline connected by a three-way valve, the first pipeline and the second pipeline are provided with a shut-off valve, an electric regulating valve and a check valve in sequence from the end of the three-way valve, the inlet end of the first pipeline is connected to steam, and the outlet end is connected to the converging section of the Venturi atomizer, the inlet end of the second pipeline is connected to compressed air, and the outlet end is connected to the converging section of the Venturi atomizer; a start-up burner connected to the outlet end of the Venturi atomizer, and a flame detector is arranged on the start-up burner; and a DCS control system connected to all valves, the ultrasonic oil atomizer, the oil pump and the flame detector.

[0006] According to the embodiment of the present application, a pressure sensor is arranged on the pipeline between the electric regulating valve and the check valve of the atomization device, and the pressure sensor is connected to the DCS control system.

[0007] According to the embodiment of the application, the secondary atomization pipeline is further arranged between the inlet end of the compressed air and the starting combustor.

[0008] According to the embodiment of the application, the secondary atomization pipeline is sequentially provided with a compressed air pressure regulating valve, a secondary atomization electric regulating valve and a check valve from the inlet end of the compressed air, a pressure sensor is arranged between the secondary atomization electric regulating valve and the check valve, and the pressure sensor is connected with the DCS control system.

[0009] According to the embodiment of the application, the DCS control system comprises an oil atomizer control cabinet, and the oil pump and the ultrasonic oil atomizer are both connected with the oil atomizer control cabinet.

[0010] According to the embodiment of the application, the waste oil purifier comprises an oil-water precipitation and layering part, an impurity filtering part and a blowdown part.

[0011] According to the embodiment of the application, a liquid level sensor is arranged in the waste oil purifier, and the liquid level sensor is connected with the DCS control system.

[0012] Compared with the prior art, the technical scheme of the application has the following beneficial effects:

[0013] 1. The Venturi tube is adopted in the utility model, the negative pressure at the nozzle of the Venturi tube mixes the fuel oil and the waste oil mist, atomizes the mixture, and obtains the oil mist with uniform mixture and high calorific value at the outlet section of the Venturi tube, so that the calorific value of the waste oil mist is increased and the ignition point of the mixture is reduced, thereby forming the atomized mixed oil mist with high calorific value to be combusted in the starting combustor, so that the contact with the coal powder is avoided, the combustion of the boiler is increased, and the fuel consumption is reduced.

[0014] 2. The compressed air of the original starting combustor is used as the secondary atomization pipeline in the utility model, the compressed air pressure regulating valve and the secondary atomization electric regulating valve can be opened according to the situation, the mixed oil mist is subjected to secondary atomization, the sufficient combustion of the mixed oil mist is ensured, and the successful ignition is ensured.

[0015] 3. The measurement and control signals of the devices such as the pressure transmitter, the electric regulating valve, the ultrasonic oil atomizer, the variable frequency oil pump and the flame detector are sent into the DCS system of the power plant for integration, the liquid level of the purifier, the oil output of the oil pump, the pressure of the atomization medium and the opening and closing of each valve are automatically controlled, time and labor are saved, and the effective combustion of the waste oil in the boiler is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme of the embodiments of the application, the drawings of the embodiments will be briefly introduced below, and obviously, the drawings in the following description only relate to some embodiments of the application, but are not limited to the application.

[0017] Figure 1 The utility model discloses an example of the structural schematic diagram.

[0018] The reference signs are explained as follows:

[0019] 1. Start burner, 2. Flame detector, 3. Venturi atomizer, 4. Electric regulating valve, 5. Check valve, 6. Pressure sensor, 7. Shut-off valve, 8. Fuel pressure regulating valve, 9. Three-way valve, 10. Waste oil purifier, 11. Oil filter screen, 12. Compressed air pressure regulating valve, 13. Oil pump, 14. Oil atomizer control cabinet, 15. Ultrasonic oil atomizer, 16. Secondary atomization electric regulating valve, 17. Oil atomizer outlet electric regulating valve.

[0020] A. Waste oil, B. Compressed air, C. Steam, D. Fuel oil. DETAILED DESCRIPTION

[0021] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0022] Unless otherwise defined, technical terms or scientific terms used herein should be understood as having the common meaning in the field of the present application to which they pertain. The terms "first", "second" and similar terms used in the patent application specification and claims of the present application do not denote any order, quantity or importance, but are used to distinguish different constituent parts. Similarly, the terms "one" or "a" or similar terms do not denote a quantity limitation, but mean that at least one exists.

[0023] As Figure 1 shown, the utility model discloses an example of a waste oil atomization combustion increasing device of CFB boiler, is related to four pipeline settings, including waste oil purification device, fuel oil device, atomization device, secondary atomization pipeline, start burner 1 and DCS control system, relative to the problem that waste oil atomization is easy to mix with coal powder and influence the combustion effect in the prior art, the utility model utilizes the function that CFB boiler start burner 1 can burn fuel oil, first, waste oil is handled and atomized, and fuel oil is atomized and mixed with atomized waste oil simultaneously by utilizing the Venturi tube, to form the atomized mixed oil mist of high calorific value and burn in start burner 1, to avoid contacting with coal powder, play the role of combustion increasing and reducing fuel consumption to boiler combustion.

[0024] In this embodiment, the waste oil purification device includes a waste oil purifier 10, an oil filter screen 11, an oil pump 13 and an ultrasonic oil atomizer 15 connected in sequence on a pipeline, the waste oil purifier 10 is connected to a waste oil treatment device of the power plant, an outlet end of the ultrasonic oil atomizer 15 is connected to a throat of the Venturi atomizer 3 through a pipeline, and an oil atomizer outlet electric regulating valve 17 is arranged on the pipeline.

[0025] Further, the waste oil purifier 10 is used to collect waste oil after maintenance of each device of the power plant, and the waste oil is treated by an oil-water precipitation stratification part, an impurity filtering part and a blowdown part of the waste oil purifier 10 and then connected to a pipeline system to preliminarily purify the waste oil. The oil filter screen 11 installed at an outlet end of the waste oil purifier 10 is used for filtering again to ensure that no impurities enter the subsequent pipeline equipment.

[0026] Further, a liquid level sensor is arranged in the waste oil purifier 10, and the liquid level sensor is connected to a DCS control system. In order to ensure purification quality, the liquid level of the purifier is controlled at a position of 1 / 3-2 / 3.

[0027] Further, the control of the oil pump 13 is controlled by an oil atomizer control cabinet 14 to ensure that the oil inlet quantity matches the oil quantity obtained by atomization and to ensure atomization effect. The oil mist after atomization enters the throat of the Venturi atomizer 3. In order to ensure stable combustion, the maximum flow of the output of the oil pump 13 is limited to be lower than 1 / 3 of the fuel quantity required for full load combustion of the start-up combustor 1.

[0028] Further, the oil pump 13 can be preferably a variable frequency oil pump.

[0029] The fuel device includes a fuel pressure regulating valve 8, a shut-off valve 7 and an electric regulating valve 4 connected in sequence on a pipeline, an inlet end of the fuel pressure regulating valve 8 is connected to a fuel storage device, and an outlet end of the electric regulating valve 4 is connected to a negative pressure area of the throat of the Venturi atomizer 3 through a pipeline.

[0030] In this embodiment, as shown in Figure 1 The atomization device includes a first pipeline and a second pipeline connected by a three-way valve 9, the first pipeline and the second pipeline are sequentially provided with a shut-off valve, an electric regulating valve 4 and a check valve 5 from the end of the three-way valve 9, an inlet end of the first pipeline is connected to steam, and an outlet end of the first pipeline is connected to a converging section of the Venturi atomizer 3, and an inlet end of the second pipeline is connected to compressed air, and an outlet end of the second pipeline is connected to the converging section of the Venturi atomizer 3.

[0031] Specifically, the electric regulating valve 4 of the atomization device can be adjusted according to the atomization effect in the Venturi tube to ensure the atomization effect of the ignition diesel oil and to match the waste oil after atomization to ensure safety and reliability in subsequent combustion. The function of the shut-off valve is to ensure reliable isolation of the pipeline in case of accidents and maintenance. The function of the fuel pressure regulating valve 8 is to regulate the pressure of the fuel.

[0032] Further, a pressure sensor 6 is arranged on the pipeline between the electric regulating valve 4 and the check valve 5 of the atomizing device, the pressure sensor 6 is connected to the DCS control system, and the pressure sensor 6 is designed to ensure the atomizing effect and ensure that the pressure of the atomizing medium is greater than 0.8 MPa. The atomizing medium enters the high-pressure inlet end of the Venturi atomizer 3 through the shutoff valve 7, the electric regulating valve 4 and the check valve 5, and the check valve 5 prevents the fuel oil from backflowing to the compressed air or steam pipeline system.

[0033] Further, a secondary atomizing pipeline is arranged between the inlet end of the compressed air and the start-up burner 1, the secondary atomizing pipeline is sequentially provided with a compressed air pressure regulating valve 12, a secondary atomizing electric regulating valve 16 and a check valve 5 from the inlet end of the compressed air, a pressure sensor 6 is arranged between the secondary atomizing electric regulating valve 16 and the check valve 5, and the pressure sensor 6 is connected to the DCS control system. In order to ensure the successful re-ignition of the start-up burner 1, the compressed air pressure regulating valve 12 and the secondary atomizing electric regulating valve 16 can be opened to perform secondary atomization on the mixed oil mist, thereby ensuring the combustion effect.

[0034] In the embodiment, the start-up burner 1 is connected to the outlet end of the Venturi atomizer 3, and the start-up burner 1 is provided with a flame detector 2. The mixed oil mist enters the start-up burner 1 to be ignited and combusted, if the flame detector 2 detects unstable flame, the compressed air pressure regulating valve 12 and the secondary atomizing electric regulating valve 16 can be opened to perform secondary atomization on the mixed oil mist by using the compressed air, thereby ensuring the combustion effect.

[0035] In the embodiment, the DCS control system is connected to all valves, the ultrasonic oil atomizer 15, the oil pump 13 and the flame detector 2. The measurement and control signals of the pressure transmitter, the electric regulating valve 4, the ultrasonic oil atomizer 15, the variable frequency oil pump 13 and the flame detector 2 are sent to the DCS system of the power plant for integration, thereby realizing the automatic control of the waste oil atomizing combustion-enhancing device.

[0036] Further, the DCS control system comprises an oil atomizer control cabinet 14, and the oil pump 13 and the ultrasonic oil atomizer 15 are connected to the oil atomizer control cabinet 14.

[0037] The application further discloses a control method of the waste oil atomizing combustion-enhancing device of the CFB boiler.

[0038] S1: Start the waste oil purifier 10 to purify the waste oil, adjust the flow of the oil pump 13, and perform steam blowing on the oil gun of the start-up burner 1 for 2-3 times, each time for not less than 30 s, and the blowing interval is not less than 10 s. The main purpose of step S1 is to remove metal impurities and water, thereby ensuring that the oil mist is beneficial to combustion after being mixed.

[0039] S2: open the fuel pressure regulating valve 8, adjust the fuel pressure to 0.6-0.8 MPa, and then open the shut-off valve 7.

[0040] S3: open the three-way valve 9, select steam or compressed air as the atomizing medium, and the atomizing medium enters the high-pressure inlet end of the Venturi atomizer 3 through the shut-off valve 7, the electric regulating valve 4, and the check valve 5. The atomizing medium enters the high-pressure inlet end of the Venturi atomizer 33 through the shut-off valve 7, the electric regulating valve 4, and the check valve 5. The check valve 5 prevents the fuel from backflowing to the compressed air or steam pipeline system.

[0041] S4: open the electric regulating valve 4 of the fuel pipeline and the electric regulating valve 4 at the outlet of the ultrasonic oil atomizer 15. The opening degrees of the two regulating valves are set in the control program to ensure that the amount of fuel entering is about twice the amount of oil mist. Due to the negative pressure at the nozzle of the Venturi tube, the fuel and waste oil mist are mixed and atomized at the same time, and a uniformly mixed and high-calorific-value oil mist is obtained at the outlet section of the Venturi tube. This oil mist can directly enter the oil gun of the starting burner 1 and cooperate with the ignition gun to perform ignition.

[0042] S5: ignite the oil gun of the starting burner 1 with the ignition gun for 30 seconds. If the flame detector 2 does not detect a flame signal, stop the ignition, quickly close the electric regulating valve 4 of the fuel pipeline, the shut-off valve 7, open the purging pipeline, and purge for 3 minutes. Stop purging and wait for the next ignition start. When igniting for the second time, open the compressed air pressure regulating valve 12 and the secondary atomizing electric regulating valve 16 to perform secondary atomization on the mixed oil mist, ensuring successful ignition again.

[0043] Further, in step S1, the liquid level of the waste oil purifier 10 is controlled at 1 / 3-2 / 3 to ensure purification quality. To ensure stable combustion, the maximum output flow of the oil pump 13 is limited to less than 1 / 3 of the amount of fuel required for full-load combustion of the starting burner 1.

[0044] Further, steam or compressed air is selected as the atomizing medium, and in step S3, the pressure of the steam or compressed air is greater than 0.8 MPa to ensure atomization effect.

[0045] The control principle of the waste oil atomization combustion increasing device of the CFB boiler in the embodiment is as follows: the first path is a waste oil purifying device, which is used for collecting waste oil after maintenance of various devices of the power plant, and the waste oil purifier 10 is internally provided with the functions of oil-water sedimentation layering, impurity filtering and pollution discharge. The waste oil after purification is filtered again through the oil filter screen 11 to ensure that no impurities enter the subsequent pipeline equipment. The clean oil passing through the oil filter screen 11 is delivered to the ultrasonic oil atomizer 15 by the variable frequency oil pump 13 for atomization. The control of the variable frequency oil pump 13 is controlled by the oil atomizer control cabinet 14 to ensure that the oil inlet amount matches the atomized oil amount, to ensure the atomization effect, and the atomized oil mist enters the throat of the Venturi atomizer 3. The second path is a fuel device, and the ignition diesel oil from the oil depot of the thermal power plant enters the negative pressure area of the throat of the Venturi atomizer 3 through the fuel pressure regulating valve 8, the shut-off valve 77 and the electric regulating valve 4 of the fuel device to be sucked into the atomizer for atomization. The electric regulating valve 4 of the fuel device can be adjusted according to the atomization effect in the Venturi tube to ensure the atomization effect of the ignition diesel oil and match the atomized waste oil to ensure safety and reliability in subsequent combustion. The function of the shut-off valve 7 is to ensure reliable isolation of the pipeline in case of an accident or maintenance, and the function of the fuel pressure regulating valve 8 is to regulate the pressure of the fuel. The third path is an atomization pipeline, and the atomization medium can be selected from steam or compressed control, and the three-way valve 9 is used for selection control. The steam or compressed air with pressure enters the converging section on the right side of the Venturi atomizer 3 through the respective pipeline shut-off valves, electric regulating valves 4 and check valves 5, the flow rate is increased, and reaches the maximum value when entering the throat, at which time the fuel oil and waste oil mist are sucked from the negative pressure of the throat. Since the relative flow rate between the gas and liquid phases is very large, the fuel oil is atomized under the high-speed airflow, and the waste oil mist is also fully mixed. The mixed oil mist enters the starting combustor 1 for ignition and combustion, and if the flame detector 2 detects unstable flame, the compressed air pressure regulating valve 12 and the secondary atomization electric regulating valve 16 can be opened to perform secondary atomization on the mixed oil mist by using compressed air to ensure the combustion effect.

[0046] In summary, the technical scheme of the present application has the following beneficial effects:

[0047] 1. The Venturi tube is adopted in the utility model, and the negative pressure at the nozzle of the Venturi tube mixes and atomizes the fuel oil and waste oil mist, the oil mist with uniform mixing and high calorific value is obtained at the outlet section of the Venturi tube, the calorific value of the waste oil mist is increased and the ignition point of the mixture is reduced, thereby forming the atomized mixed oil mist with high calorific value to be combusted in the starting combustor, so that contact with the coal powder is avoided, the combustion of the boiler is increased, and the fuel consumption is reduced.

[0048] 2. The utility model discloses a compressed air of original starting combustor as secondary atomization pipeline, can according to situation and can open compressed air pressure regulating valve, secondary atomization electric regulating valve, carries out secondary atomization to mixed oil mist, ensures mixed oil mist fully burns, ensures successful ignition again.

[0049] 3. The application will send the measurement, control signal of the equipment of pressure transmitter, electric regulating valve, ultrasonic oil atomizer, variable frequency oil pump and flame detector into the DCS system of power plant to carry out integration, realizes the automation control to the liquid level of purifier, oil pump oil output, the pressure of atomization medium, the switch of each valve, saves time and labour and ensures the effective combustion of waste oil in the boiler.

[0050] The above is only the exemplary embodiment of the application, and is not used to limit the protection scope of the application, and the protection scope of the application is determined by the appended claims.

Claims

1. A waste oil atomization and combustion enhancement device for a CFB boiler, characterized in that, include: Waste oil purification device includes a waste oil purifier, an oil filter, an oil pump and an ultrasonic oil atomizer connected in sequence on a pipeline. The waste oil purifier is connected to the waste oil treatment device of a power plant. The outlet end of the ultrasonic oil atomizer is connected to the throat of a Venturi atomizer through a pipeline. An electric regulating valve for the outlet of the oil atomizer is provided on the pipeline. The fuel system includes a fuel pressure regulating valve, a shut-off valve, and an electric regulating valve connected in sequence on a pipeline. The inlet end of the fuel pressure regulating valve is connected to a fuel storage device, and the outlet end of the electric regulating valve is connected to the negative pressure zone of the throat of a venturi atomizer through a pipeline. The atomizing device includes a first pipeline and a second pipeline connected by a three-way valve. The first pipeline and the second pipeline are sequentially provided with a shut-off valve, an electric regulating valve and a check valve starting from the end of the three-way valve. The inlet end of the first pipeline is connected to steam and the outlet end is connected to the converging section of a Venturi atomizer. The inlet end of the second pipeline is connected to compressed air and the outlet end is connected to the converging section of a Venturi atomizer. Start the burner, connecting it to the outlet end of the Venturi atomizer; the starter burner is equipped with a flame detector; and The DCS control system connects all valves, ultrasonic oil atomizers, oil pumps, and flame detectors.

2. The waste oil atomization and combustion enhancement device for a CFB boiler according to claim 1, characterized in that, A pressure sensor is installed on the pipeline between the electric regulating valve and the check valve of the atomizing device, and the pressure sensor is connected to the DCS control system.

3. The waste oil atomization and combustion enhancement device for a CFB boiler according to claim 1, characterized in that, A secondary atomization pipeline is also provided between the inlet of the compressed air and the starter burner.

4. The waste oil atomization and combustion enhancement device for a CFB boiler according to claim 3, characterized in that, The secondary atomization pipeline is provided with a compressed air pressure regulating valve, a secondary atomization electric regulating valve and a check valve in sequence from the compressed air inlet end. A pressure sensor is provided between the secondary atomization electric regulating valve and the check valve. The pressure sensor is connected to the DCS control system.

5. The waste oil atomization and combustion enhancement device for a CFB boiler according to claim 1, characterized in that, The DCS control system includes an oil atomizer control cabinet, and the oil pump and ultrasonic oil atomizer are both connected to the oil atomizer control cabinet.

6. The waste oil atomization and combustion enhancement device for a CFB boiler according to claim 1, characterized in that, The waste oil purifier includes an oil-water sedimentation and stratification section, an impurity filtration section, and a sewage discharge section.

7. The waste oil atomization and combustion enhancement device for a CFB boiler according to claim 1, characterized in that, The waste oil purifier is equipped with a liquid level sensor, which is connected to the DCS control system.

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