CN105675499B - A Reverse Reaction Crystallization Device for Measuring SCR Solid Reductant - Google Patents

Abstract

The invention discloses a reverse reaction crystallization device for measuring SCR solid reductant, including a platform controller, a pressure regulating valve, a laser generator, a photosensitive resistance module, a large circulation heating water tank, a small circulation heating water tank, a large circulation water pump, a small circulation water pump, Electronically controlled nozzles, large circulation temperature sensor, small circulation temperature sensor, pressure sensor, water passage quartz glass tube, air passage quartz glass pipe, pressure regulating valve and computer, and the side of the pressure regulating valve is provided with a pre-valve mixed gas input pipeline And the other side of the pressure regulating valve is provided with a mixed gas pipeline after the valve, the mixed gas input pipeline before the valve and the mixed gas pipeline after the valve are both connected to the pressure regulating valve, and the top of the pressure regulating valve is fixed with a water outlet E and The waterway inlet D is fixed at the bottom of the pressure regulating valve. The SCR solid reductant reverse reaction crystallization device can measure the pressure and temperature relationship corresponding to the mixed gas generated after the SCR solid reductant is heated, and the reverse reaction to generate solid powder again.

Description

A Reverse Reaction Crystallization Device for Measuring SCR Solid Reductant

technical field

The invention specifically relates to a device for measuring the reverse reaction crystallization of an SCR solid reductant, which is used to measure the temperature corresponding to the crystallization of the mixed gas generated by the solid SCR reductant under different pressures.

Background technique

The continuous aggravation of environmental pollution and the improvement of environmental awareness around the world have prompted the continuous upgrading of automobile emission regulations. As an effective means to reduce NOx emissions from diesel vehicles, urea SCR technology has been widely used in the world. However, when the exhaust gas temperature is lower than 250°C, urea cannot be completely decomposed, so that the reducing agent needed to reduce NOx—NH3 cannot be obtained, and by-products that cause SCR catalyst failure will also be produced. For conversion efficiency, some people propose to use ammonium carbamate, ammonium carbonate, ammonium bicarbonate and other ammonium salts as raw materials to provide NH3, because such ammonium salts are cheap, have a low decomposition temperature, and are not limited by the exhaust temperature. NH3 can be quickly decomposed within the temperature range, thereby improving the conversion efficiency of NOx and reducing NOx emissions.

To use ammonium salt as the source of reducing agent, it is necessary to clarify the properties, decomposition process, and decomposition temperature of the ammonium salt. The decomposition of ammonium salts such as ammonium carbamate and ammonium carbonate is a reversible reaction, and the thermal decomposition rate of ammonium salt increases with the increase of temperature. The generated gas can be repolymerized below a certain temperature to form solid crystalline powder. If the powder is generated at the pressure transmitter, pressure regulating valve, and nozzle, it will make it difficult to accurately control the amount of NH3 injection, thereby affecting the conversion efficiency of NOx . In order to avoid the generation of reverse reaction crystal powder, it is necessary to clarify the crystallization temperature of the mixed gas generated by the decomposition of ammonium salt. Therefore, we propose a reverse reaction crystallization device for measuring SCR solid reductant.

Contents of the invention

The technical problem to be solved in the present invention overcomes the existing defects, and provides a reverse reaction crystallization device for measuring SCR solid reductant, which can measure the temperature corresponding to the crystallization of the mixed gas under different gas pipeline pressures, so as to provide a solid ammonium salt SCR system The pipeline insulation design provides a theoretical basis, improves energy utilization efficiency, reduces NOx emissions, and protects the atmospheric environment, which can effectively solve the problems in the background technology.

In order to solve the problems of the technologies described above, the present invention provides the following technical solutions:

The invention provides a reverse reaction crystallization device for measuring SCR solid reductant, including a platform controller, a pressure regulating valve, a laser generator, a photoresistor module, a large circulation heating water tank, a small circulation heating water tank, a large circulation water pump, a small circulation water pump, an electric control nozzle, large circulation temperature sensor, small circulation temperature sensor, pressure sensor, water channel quartz glass tube, gas channel quartz glass tube, pressure regulating valve and computer. The other side of the pressure regulating valve is provided with a mixed gas pipeline after the valve. Both the mixed gas input pipeline before the valve and the mixed gas pipeline after the valve are connected with the pressure regulating valve. The bottom of the pressure valve is fixed with a waterway inlet D, one end of the pre-valve mixed gas input pipeline is provided with an inlet A, and the outer part of the pre-valve mixed gas input pipeline is provided with a pre-valve heat preservation pipeline, and the front valve heat preservation pipeline is One end is provided with an inlet B and an outlet C arranged at the other end of the heat preservation pipeline before the valve. One end of the mixed gas pipeline after the valve is fixedly connected with an electronically controlled nozzle, and the mixed gas pipeline after the valve is equipped with a small circulation heat preservation pipe after the valve and the inlet H and outlet I between the small circulation insulation pipeline behind the valve and the large circulation insulation pipeline in front of the nozzle. One end of the large circulation insulation pipeline in front of the nozzle is provided with an inlet J And the outlet K at the other end located on one side of the electronically controlled nozzle, one end of the small circulation heat preservation pipeline after the valve is provided with an inlet F and the other end is provided with an outlet G, and the outlet G is connected to the inlet H, as well as the outlet I and the inlet J. Isolation, a pressure sensor is set between the outlet G and the inlet H, a small cycle temperature sensor is fixed on the side of the outlet G, and a gas path quartz glass tube is installed inside the valve mixed gas pipeline and installed in the gas path The water channel quartz glass tube outside the quartz glass tube, the gas channel quartz glass tube and the water channel quartz glass tube are both arranged between the inlet F and the outlet G, and the top of the water channel quartz glass tube is provided with a laser generator and a water channel quartz glass tube A photoresistor module is provided at the bottom, and the small circulating heating water tank is connected to the small circulating water pump. The bottom of the small circulating heating water tank is provided with an inlet L, and one side of the small circulating water pump is provided with an outlet M. The large circulating heating water tank and The large circulating water pump is connected, the bottom of the large circulating heating water tank is provided with an inlet N, and the side of the large circulating water pump is provided with an outlet P.

As a preferred technical solution of the present invention, the computer, large cycle temperature sensor, small cycle temperature sensor, pressure sensor and photoresistor module are respectively electrically connected to the platform controller, and the laser generator is electrically connected to the photoresistor module.

As a preferred technical solution of the present invention, the electronically controlled nozzle receives a control signal from the platform controller to control the injection of the mixed gas.

As a preferred technical solution of the present invention, the heating function of the large circulation heating water tank and the on-off of the large circulation water pump are controlled by the platform controller.

As a preferred technical solution of the present invention, the heating function of the small circulation heating water tank and the on-off of the small circulation water pump are controlled by the platform controller.

As a preferred technical solution of the present invention, the inner diameter of the heat preservation pipeline before the valve is larger than the outer diameter of the mixed gas input pipeline before the valve, and the inner diameter of the small circulation heat preservation pipeline after the valve and the large circulation heat preservation pipeline in front of the nozzle Both are larger than the outer diameter of the mixed gas pipeline after the valve.

As a preferred technical solution of the present invention, the outlet M is connected to the inlet F, the outlet G is connected to the inlet H, and the outlet I is connected to the inlet L.

As a preferred technical solution of the present invention, the outlet E is connected to the inlet J, the outlet K is connected to the inlet J, and the outlet K is connected to the inlet N.

The beneficial effect achieved by the invention is: a reverse reaction crystallization device for measuring the SCR solid-state reducing agent, and the laser light generated by the laser generator reaches the photosensitive resistance module through the quartz glass tube. After the mixed gas passes through the pressure regulating valve to adjust the pressure, reduce the temperature of the heat preservation pipeline. When the temperature drops to a certain value, the mixed gas will form crystalline powder on the inner wall of the quartz glass tube of the gas path. At the same time, the light intensity received by the photoresistor will At this time, the measured mixed gas pressure and the temperature of the insulation pipeline are in a corresponding relationship, that is, the temperature corresponding to the crystallization of the mixed gas, thus providing a theoretical basis for the pipeline insulation design of the solid ammonium salt SCR system and improving energy utilization efficiency , reduce NOx emissions and protect the atmospheric environment.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention.

In the attached picture:

1 is a schematic diagram of the overall structure of a reverse reaction crystallization device for measuring SCR solid reductant described in an embodiment of the present invention;

Labels in the figure: 1. Mixed gas input pipeline before the valve; 2. Insulation pipeline before the valve; 3. Pressure regulating valve; 4. Small circulation insulation pipeline after the valve; 5. Quartz glass tube for water passage; Gas pipeline; 7. Quartz glass tube of gas path; 8. Laser generator; 9. Photoresistor module; 10. Large circulation heat preservation pipeline in front of the nozzle; 11. Electronically controlled nozzle; 12. Pressure sensor; 13. Small circulation temperature sensor 14. Large circulation temperature sensor; 15. Platform controller; 16. Small circulation heating water tank; 17. Small circulation water pump; 18. Large circulation heating water tank; 19. Large circulation water pump; 20. Computer.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

Example: Please refer to Figure 1, the mixed gas generated by the SCR solid reducing agent enters the pre-valve mixed gas input pipeline 1 from the inlet A, and the pre-valve mixed gas input pipeline 1 communicates with the pressure regulating valve 3, and the mixed gas is regulated After the pressure is adjusted by the pressure valve 3, it enters the mixed gas pipeline 6 after the valve, and the electronically controlled nozzle 11 receives the control signal from the platform controller 15 to control the injection of the mixed gas.

Large circulation heating water tank 18 and large circulation water pump 19 provide hot water for maintaining pipeline temperature for large circulation. The heating function of the large circulation heating water tank 18 and the on-off of the large circulation water pump 19 are controlled by the platform controller 15 . The hot water heated by the large circulation heating water tank 18 flows out from the outlet M of the large circulation water pump 19, passes through the inlet B, flows into the pre-valve insulation pipeline 2, then flows out from the outlet C of the pre-valve insulation pipeline 2, and flows into the pressure regulating valve 3, the waterway inlet D flows out from the waterway outlet E of the pressure regulating valve 3, and then flows into the inlet J of the large circulation heat preservation pipeline 10 in front of the nozzle, flows out from the outlet K of the large circulation heat preservation pipeline 10 in front of the nozzle, and enters the inlet N to flow back Large circulation heating water tank 18. In this way, a large circulating waterway is formed. The circulation sequence of the large circulating waterway is: exit P——entry B——exit C——entrance D——exit E——entrance J——exit K——entrance N——exit P.

Small circulation heating water tank 16 and small circulation water pump 17 provide the hot water that keeps pipeline temperature for small circulation. The heating function of the small circulating heating water tank 16 and the on-off of the small circulating water pump 17 are controlled by the platform controller 15 . The hot water heated by the small circulation heating water tank 16 flows out from the outlet M of the small circulation water pump 17, passes through the inlet F, flows into the small circulation insulation pipeline 4 after the valve, and flows out by the outlet G. The small circulating water flows out from the outlet G and enters the inlet H, and then flows out through the outlet I. The waterway between the inlet F and the outlet I is the small circulation insulation pipeline after the valve. The outlet G and the inlet H are isolated from each other, but the mixed gas pipeline 6 after the valve can pass through. A pressure sensor 12 is installed between the outlet G and the inlet H to monitor the gas pressure in the after-valve mixed gas pipeline 6 , and the signal of the pressure sensor 12 is sent to the platform controller 15 . The signal of the pressure sensor 12 is sent to the platform controller 15 to control whether the small circulation heating water tank 16 heats the circulating water. The circulation sequence of the small circulating waterway is: exit M——entrance F——exit G——entrance H——exit I——entrance L——exit M.

The photoresistor module 9 receives the laser light from the laser generator 8 . The photoresistor module 9 can convert the light intensity of the laser into a voltage signal and send it to the platform controller 15 .

The working process of the experimental platform: first add a certain amount of pure water to the small circulation heating water tank 16 and the large circulation heating water tank 18, and the platform controller 15 sends a signal to the small circulation heating water tank 16 and the large circulation heating water tank 18 to start heating and start the small circulation Water pump 17 and large circulation water pump 19, small circulation and large circulation are opened simultaneously. The small circulation temperature sensor 13 and the large circulation temperature sensor 14 transmit the small circulation water temperature and the large circulation water temperature to the platform controller 15 respectively.

When the temperature of the small cycle and the large cycle reaches ℃, keep the temperature stable. Pass the gas generated by the SCR solid ammonium salt into the gas inlet A of the experimental platform, use the pressure regulating valve 3 to adjust the gas pressure to a certain value, and the pressure sensor 12 monitors the gas pressure behind the pressure regulating valve 3 and transmits the pressure signal to the platform controller 15. The platform controller 15 sends a signal to the electronically controlled nozzle 11 to maintain a certain injection pulse width, and adjust the pressure regulating valve 3 again so that the gas pressure behind the valve reaches the desired experimental pressure value.

After the pressure adjustment is completed, turn on the laser generator 8 and the photoresistor module 9, the photoresistor module 9 transmits the voltage signal of the light intensity to the platform controller 15 in real time, and the platform controller 15 transmits the temperature, pressure and light intensity voltage signals to the computer in real time 20. The computer 20 displays and records the above-mentioned signals in real time. Maintain the temperature of the large circulation waterway, stop the heating function of the small circulation heating water tank 16, and the small circulation water pump 17 continues to work. When the temperature of the small circulating waterway keeps decreasing and reaches a certain temperature, the mixed gas will form crystalline powder on the inner wall of the quartz glass tube 7 of the gas path. At the same time, the light intensity received by the photosensitive resistor module 9 will weaken, and the corresponding voltage signal will occur. Variety. The temperature of the small circulating water measured at this time is the temperature corresponding to the crystallization of the mixed gas under a certain pressure, that is, under this gas pressure, as long as the temperature is equal to or lower than the corresponding temperature when the light intensity changes, the mixed gas will Gas will produce crystalline powder.

By repeating the above steps, the crystallization temperature corresponding to different gas mixture pressures can be measured.

It should be noted that the present invention is a reverse reaction crystallization device for measuring SCR solid reductant. After the mixed gas passes through the pressure regulating valve 3 to adjust the pressure, the temperature of the heat preservation pipeline is reduced. When the temperature drops to a certain value, the mixed gas will be in the The inner wall of the gas path quartz glass tube 7 forms crystal powder, and at the same time, the light intensity received by the photoresistor will change. The pressure of the mixed gas measured at this time corresponds to the temperature of the insulation pipeline, that is, the temperature corresponding to the crystallization of the mixed gas. The invention can measure the crystallization temperature corresponding to different mixed gas pressures, and provides theoretical support for the design and stable operation of the solid-state SCR system.

Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still The technical solutions recorded in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. The utility model provides a survey SCR solid-state reductant reverse reaction crystallization device, including platform controller (15), air-vent valve (3), laser generator (8), photoresistor module (9), big circulation heating water tank (18), little circulation heating water tank (16), big circulating water pump (19), little circulating water pump (17), automatically controlled nozzle (11), big circulation temperature sensor (14), little circulation temperature sensor (13), pressure sensor (12), water route quartz glass pipe (5), gas circuit quartz glass pipe (7), air-vent valve (3) and computer (20), characterized in that, air-vent valve (3) one side is equipped with mixed gas input pipeline before the valve (1) and air-vent valve (3) opposite side is equipped with mixed gas pipeline after the valve (6), mixed gas input pipeline before the valve (1) and air-vent valve (6) all communicate with air-vent valve (3), air-vent valve (3) top is fixed to be equipped with water route export E and air-vent valve (3) bottom is fixed to be equipped with water route entry D, mixed gas input pipeline before the valve (1) one end is equipped with entry A, mixed gas input pipeline before the valve (1) outside is equipped with valve before the valve (2) and heat preservation valve before the valve (2) keeps warm and heat preservation pipeline before the other end (2) keeps warm and holds the valve after the valve (2), an electric control nozzle (11) is fixedly communicated with one end of the mixed gas pipeline (6) behind the valve, a small circulation heat preservation pipeline (4) behind the valve and a large circulation heat preservation pipeline (10) in front of the nozzle and an inlet H and an outlet I arranged between the small circulation heat preservation pipeline (4) behind the valve and the large circulation heat preservation pipeline (10) in front of the nozzle are arranged outside the mixed gas pipeline (6) behind the valve, one end of the large circulation heat preservation pipeline (10) in front of the nozzle is provided with an inlet J and an outlet K positioned at the other end of one side of the electric control nozzle (11), one end of the small circulation heat preservation pipeline (4) behind the valve is provided with an inlet F and the other end is provided with an outlet G, the outlet G is mutually isolated with the inlet H and the outlet I and the inlet J, a pressure sensor (12) is arranged between the outlet G and the inlet H, one side of the outlet G is fixedly provided with a small circulation temperature sensor (13), a gas circuit quartz glass tube (7) and a waterway glass tube (5) arranged outside the large circulation heat preservation pipeline (7) in front of the valve, the quartz glass tube (7) and the quartz glass tube (7) are internally mounted, one end of the small circulation glass tube (7) and the waterway glass tube (5) are respectively arranged at the outer side of the quartz glass tube (7), the small circulation glass tube (17) and the small circulation glass tube (16) are connected with a small waterway (16) and a small waterway pump (17), the utility model discloses a laser generator, including little circulation heating water tank (16), little circulation heating water tank (17) one side is equipped with export M, big circulation heating water tank (18) and big circulation water pump (19) are connected, big circulation heating water tank (18) bottom is equipped with entry N, big circulation water pump (19) one side is equipped with export P, computer (20), big circulation temperature sensor (14), little circulation temperature sensor (13), pressure sensor (12) and photo resistance module (9) respectively with platform controller (15) electricity federation, laser generator (8) and photo resistance module (9) electricity federation, automatically controlled nozzle (11) accept the control signal from platform controller (15), control mixture's injection.

2. The device for detecting the reverse reaction crystallization of the SCR solid reducing agent according to claim 1, wherein the heating function of the large circulation heating water tank (18) and the on-off of the large circulation water pump (19) are controlled by the platform controller (15).

3. The device for measuring the reverse reaction crystallization of the SCR solid reducing agent according to claim 1, wherein the heating function of the small circulation heating water tank (16) and the on-off of the small circulation water pump (17) are controlled by the platform controller (15).

4. The device for determining the reverse reaction crystallization of the SCR solid reducing agent according to claim 1, wherein the inner diameter of the pre-valve heat preservation pipeline (2) is larger than the outer diameter of the pre-valve mixed gas input pipeline (1), and the inner diameters of the post-valve small circulation heat preservation pipeline (4) and the pre-nozzle large circulation heat preservation pipeline (10) are both larger than the outer diameter of the post-valve mixed gas pipeline (6).

5. The apparatus for detecting the reverse reaction crystallization of a solid reducing agent of SCR according to claim 1, wherein the outlet M is connected to the inlet F, the outlet G is connected to the inlet H, and the outlet I is connected to the inlet L.

6. The device for detecting the reverse reaction crystallization of the SCR solid-state reducing agent according to claim 1, wherein the outlet P is connected with the inlet B, the outlet C is connected with the inlet D, the outlet E is connected with the inlet J, the outlet K is connected with the inlet J, and the outlet K is connected with the inlet N.

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