阅读说明：本技术 一种用于测量脱硝装置内烟气中氨浓度的装置及方法 (Device and method for measuring ammonia concentration in flue gas in denitration device ) 是由 陆超 王东 陈艺秋 张杨 杜振 晏敏 朱文韬 王丰吉 于 2020-04-10 设计创作，主要内容包括：本发明公开了一种用于测量脱硝装置内烟气中氨浓度的装置及方法,首先配置一个采样管装置,作为火电厂现场或实验室中接收烟气的连接装置,采样管段上配有过滤棉用于过滤烟气中的杂质。然后烟气通过烟气过滤器汽水分离且过滤后进入氨敏电极测试装置,对进入的烟气进行测量分析。同时,剩余的烟气依次流经烟气采样泵和烟气尾气处理装置,处理后的尾气排出。烟气采样泵带有变频装置,可以通过设定的流量和差压主动实时调节采样泵的出力,以稳定抽取烟气的流速。本发明避免了采用化学法、激光法等存在的测量氨浓度不准确、不及时、以及带来工程应用中喷氨过量导致氨与三氧化硫反应生成硫酸氢铵堵塞下游设备等问题。(The invention discloses a device and a method for measuring ammonia concentration in flue gas in a denitration device. Then the flue gas enters an ammonia sensitive electrode testing device after being subjected to steam-water separation and filtration by a flue gas filter, and the entering flue gas is measured and analyzed. Meanwhile, the residual flue gas flows through the flue gas sampling pump and the flue gas tail gas treatment device in sequence, and the treated tail gas is discharged. The flue gas sampling pump is provided with a frequency conversion device, and can actively adjust the output of the sampling pump in real time through the set flow and differential pressure so as to stably extract the flow velocity of the flue gas. The method avoids the problems that the ammonia concentration is measured inaccurately and untimely by adopting a chemical method, a laser method and the like, and the ammonia and sulfur trioxide react to generate ammonium bisulfate to block downstream equipment due to excessive ammonia spraying in engineering application, and the like.)

1. A device for measuring the ammonia concentration in flue gas in a denitration device is characterized by comprising a sampling pipe device (7) and an ammonia concentration testing device (16); the sampling pipe device (7) comprises a sampling head (1) with a thermocouple, a first-stage pipe section (2) with filter cotton, a diode section (3) with the filter cotton, a third-stage pipe section (4) with the filter cotton, a fourth-stage pipe section (5) with the filter cotton and a first connecting block (6), wherein the sampling head (1), the first-stage pipe section (2), the diode section (3), the third-stage pipe section (4), the fourth-stage pipe section (5) and the first connecting block (6) are sequentially connected; the ammonia concentration testing device (16) comprises a second connecting block (8), a flue gas filter (9), an ammonia sensitive electrode testing device (10), a flue gas sampling pump (11), a flue gas tail gas processing device (12), a controller (13) and an integrated control display (14), the second connecting block (8), the flue gas filter (9), the ammonia sensitive electrode testing device (10), the flue gas sampling pump (11) and the flue gas tail gas processing device (12) are sequentially connected through a flue gas pipeline (15) with a heat tracing pipe and a thermocouple, the flue gas filter (9), the ammonia sensitive electrode testing device (10), the flue gas sampling pump (11) and the flue gas tail gas treatment device (12) are all arranged on the fixing device (17), the integrated control display (14), the ammonia-sensitive electrode testing device (10) and the flue gas sampling pump (11) are all connected with a controller (13); the first connecting block (6) is connected with the second connecting block (8).

2. The device for measuring the ammonia concentration in flue gas of a denitration device according to claim 1, wherein the sampling pipe device (7) is of a structure which can stretch the length of the pipe section, and the primary pipe section (2), the diode section (3), the triode section (4) and the quaternary pipe section (5) are all of a sealing structure.

3. The device for measuring the ammonia concentration in flue gas in a denitration device according to claim 1, wherein the flue gas filter (9) filters flue gas with a small amount of particulate matters into particulate-free flue gas, prevents pollution of subsequent equipment, realizes steam-water separation, filters water in flue gas, and allows dry flue gas to flow through.

4. Device according to claim 1, characterized in that the flue gas sampling pump (11) is used to power the extraction of flue gas and that the flue gas sampling pump (11) is equipped with a frequency converter.

5. The apparatus for measuring the ammonia concentration in flue gas in a denitration apparatus according to claim 1, wherein said flue gas off-gas treatment apparatus (12) treats the remaining flue gas flowing through the ammonia-sensitive electrode test apparatus (10) as clean flue gas and discharges the clean flue gas to the outside of the ammonia concentration test apparatus (16).

6. The apparatus for measuring the ammonia concentration in flue gas in a denitration apparatus according to claim 1, wherein the start and stop of the ammonia sensitive electrode test apparatus (10) and the flue gas sampling pump (11) are controlled by sending instructions on the integrated control display (14) and transmitting the instructions from the controller (13) to the ammonia sensitive electrode test apparatus (10) and the flue gas sampling pump (11); the thermocouple on the sampling head (1) is transmitted to the integrated control display (14) through the controller (13), and an instruction is sent out on the integrated control display (14) to control the temperature in the flue gas pipeline (15) through which the flue gas flows to be consistent with the temperature at the sampling head (1).

7. A method of operating an apparatus for measuring the ammonia concentration in flue gas in a denitration apparatus according to any one of claims 1 to 6, characterized by the following procedure: firstly, the preheating temperature of an ammonia concentration testing device (16) is set through an integrated control display (14), a flue gas pipeline (15) is heated, when the temperature reaches a set value, a sampling pipe device (7) is inserted into a flue, and the length is adjusted as required; then setting the flow rate of smoke extraction on an integrated control display (14), clicking to start sampling, controlling and starting a smoke sampling pump (11) with a frequency converter through a controller (13), enabling smoke to enter an ammonia concentration testing device (16) and pass through a smoke filter (9) for steam-water separation and filtration, enabling dry smoke to flow into an ammonia sensitive electrode testing device (10), enabling the ammonia sensitive electrode testing device (10) to automatically extract a proper amount of smoke for measurement and analysis, transmitting a measurement value to the integrated control display (14) through the controller (13), enabling the smoke flowing through the ammonia sensitive electrode testing device (10) to sequentially flow through the smoke sampling pump (11) and a smoke tail gas processing device (12), and discharging the smoke to the outside of the ammonia concentration testing device (16) after tail gas processing; the ammonia concentration testing device (16) is preheated before being used by the heating flue gas pipeline (15), and real-time adjustment is carried out by the temperature fed back by the thermocouple on the sampling head (1), so that the flue gas temperature in the flue gas pipeline (15) is consistent with the field condition; the output of the flue gas sampling pump (11) is intelligently adjusted by a frequency converter, so that the flow speed of the extracted flue gas is ensured to be stable; and after the measurement is finished, clicking a stop button on the integrated control display (14) to stop working.

Technical Field

The invention relates to a device and a method for measuring ammonia concentration in flue gas in a denitration device.

Background

At present, the domestic environmental protection situation is severe, and the standard of environmental protection of the smoke is provided for large coal-fired power plants and the chemical energy industry. Flue gas denitration of thermal power plant is a flue gas environmental protection type technique that the technique is very mature and use many years, and present the vast majority denitration route be Selective Catalytic Reduction (SCR) denitration technique, but use this technique in thermal power plant and also do not avoid having some technological not enough, for example the reductant ammonia that uses in the denitration can react with sulfur trioxide in the flue gas and generate ammonium bisulfate, block up downstream equipment such as air preheater to produce adverse effect to the denitration catalyst. The control of the ammonia content in the flue gas is good, and reasonable ammonia injection is one of the fundamental methods for solving the problem. For complex and variable working conditions on site, it becomes especially important to measure the ammonia concentration at each point in the SCR region quickly and accurately.

Disclosure of Invention

The invention aims to overcome various problems of inaccurate and untimely ammonia concentration measurement in the prior art and bring about the condition that ammonia and sulfur trioxide react to generate ammonium bisulfate to block downstream equipment due to excessive ammonia spraying in engineering application, and provides a device and a method for measuring the ammonia concentration in flue gas in a denitration device.

The technical scheme adopted by the invention for solving the problems is as follows: a device for measuring the ammonia concentration in flue gas in a denitration device is characterized by comprising a sampling pipe device and an ammonia concentration testing device; the sampling pipe device comprises a sampling head with a thermocouple, a primary pipe section with filter cotton, a diode section with the filter cotton, a triode section with the filter cotton, a quaternary pipe section with the filter cotton and a first connecting block, wherein the sampling head, the primary pipe section, the diode section, the quaternary pipe section and the first connecting block are sequentially connected; the ammonia concentration testing device comprises a second connecting block, a smoke filter, an ammonia-sensitive electrode testing device, a smoke sampling pump, a smoke tail gas processing device, a controller and an integrated control display, wherein the second connecting block, the smoke filter, the ammonia-sensitive electrode testing device, the smoke sampling pump and the smoke tail gas processing device are sequentially connected through a smoke pipeline with a heat tracing pipe and a thermocouple, the smoke filter, the ammonia-sensitive electrode testing device, the smoke sampling pump and the smoke tail gas processing device are all arranged on a fixing device, and the integrated control display, the ammonia-sensitive electrode testing device and the smoke sampling pump are all connected with the controller; the first connecting block is connected with the second connecting block.

Furthermore, the sampling pipe device is a structure capable of extending the length of the pipe section of the sampling pipe device, and the first-level pipe section, the diode section, the triode section and the fourth-level pipe section are all sealing structures, so that internal smoke is prevented from leaking outside. The sampling pipe device is provided with a sampling head with a thermocouple, and the flue gas enters the sampling pipe device from the sampling head. The sampling head is provided with a thermocouple for measuring the temperature of the flue gas. The filter cotton of each pipe section can filter impurities in the flue gas.

Furthermore, the flue gas filter can filter the flue gas with a small amount of particulate matters into the flue gas without the particulate matters, so that subsequent equipment is prevented from being polluted, the steam-water separation can be realized, the moisture in the flue gas is filtered, and the dry flue gas flows through the flue gas filter.

Furthermore, the flue gas sampling pump is used for providing power for extracting flue gas, and the flue gas sampling pump is provided with a frequency converter, so that the output of the flue gas sampling pump can be conveniently adjusted in real time, and the flue gas flow is ensured to be uniform and stable.

Further, the flue gas tail gas treatment device can treat the residual flue gas flowing through the ammonia-sensitive electrode testing device into clean flue gas and discharge the clean flue gas to the outside of the ammonia concentration testing device.

Further, an instruction is sent out on the integrated control display and is transmitted to the ammonia-sensitive electrode testing device and the flue gas sampling pump by the controller, and the ammonia-sensitive electrode testing device and the flue gas sampling pump are controlled to start and stop; and the thermocouple on the sampling head is transmitted to the integrated control display through the controller, and an instruction is sent out on the integrated control display to control the temperature in a flue gas pipeline through which flue gas flows to be consistent with the temperature at the sampling head.

The working method of the device for measuring the ammonia concentration in the flue gas in the denitration device is characterized by comprising the following steps of: firstly, setting the preheating temperature of an ammonia concentration testing device through an integrated control display, heating a flue gas pipeline, inserting a sampling pipe device into a flue after the temperature reaches a set value, and adjusting the length as required; then setting the flow rate of smoke extraction on the integrated control display, clicking to start sampling, controlling and starting a smoke sampling pump with a frequency converter through a controller, enabling smoke to enter an ammonia concentration testing device, performing steam-water separation and filtration through a smoke filter, enabling dry smoke to flow into an ammonia-sensitive electrode testing device, automatically extracting a proper amount of smoke by the ammonia-sensitive electrode testing device, performing measurement analysis, transmitting a measurement value to the integrated control display through the controller, enabling the smoke flowing through the ammonia-sensitive electrode testing device to sequentially flow through the smoke sampling pump and a smoke tail gas treatment device, and discharging the smoke after tail gas treatment to the outside of the ammonia concentration testing device; preheating the ammonia concentration testing device before use through a heating flue gas pipeline, and adjusting the temperature fed back by a thermocouple on a sampling head in real time to ensure that the flue gas temperature in the flue gas pipeline is consistent with the field condition; the output of the flue gas sampling pump is intelligently adjusted by a frequency converter, so that the flow velocity of the extracted flue gas is ensured to be stable; and after the measurement is finished, clicking a stop button on the integrated control display to stop working.

Compared with the prior art, the invention has the following advantages and effects: the method is characterized in that a flue gas sampling pump with a frequency converter is firstly configured, and is generally in a negative pressure state when used in a flue of a power plant, so that a certain suction force is needed, and the sampling pump provides stable suction force for collecting flue gas, so that stable flue gas flow is ensured. The sampling pipe device is directly contacted with the on-site flue and is provided with a sampling head with a thermocouple, flue gas enters from the sampling head, the thermocouple can measure the temperature of the flue gas in the flue, the sampling pipe is divided into four sections, the sampling pipe is telescopic and suitable for the on-site wide flue, and each section is provided with own filter cotton for filtering impurities in the flue gas. Secondly, the flue gas passes through in the sampling pipe device enters into ammonia concentration testing arrangement, still is provided with filter equipment in the device and is used for steam-water separation to filter all impurity and moisture content, guarantees to enter into the flue gas of the quick electrode testing arrangement of ammonia and is clean dry flue gas, compares traditional chemistry method and laser method, and the quick electrode method of ammonia measures ammonia concentration accurate and quick. And the residual flue gas is discharged after being treated by the flue gas tail gas treatment device.

The method avoids the problems that the ammonia concentration is measured inaccurately and untimely by adopting a chemical method, a laser method and the like, and the ammonia and sulfur trioxide react to generate ammonium bisulfate to block downstream equipment due to excessive ammonia spraying in engineering application, and the like.

Drawings

FIG. 1 is a schematic structural diagram of a sampling tube assembly in an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of an ammonia concentration measuring apparatus according to an embodiment of the present invention.

In the figure: the device comprises a sampling head 1, a first-level pipe section 2, a diode section 3, a triode section 4, a fourth-level pipe section 5, a first connecting block 6, a sampling pipe device 7, a second connecting block 8, a flue gas filter 9, an ammonia sensitive electrode testing device 10, a flue gas sampling pump 11, a flue gas tail gas processing device 12, a controller 13, an integrated control display 14, a flue gas pipeline 15, an ammonia concentration testing device 16 and a fixing device 17.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.