Diesel engine tail gas emission simulation and detection equipment

Abstract

The utility model discloses diesel engine tail gas emission simulation and detection equipment, which comprises an engine work simulation device, a gas treatment device and an ammonia gas absorption device which are connected in sequence, and the gas treatment device comprises an oxidation type catalyst, a wall flow type particle trap and a selective catalytic reduction device which are connected in sequence; a gas sensor is arranged between the engine work simulation device and the gas treatment device; a density concentration detector is arranged in the ammonia gas absorption device. According to the utility model, the working condition of the diesel engine is simulated, detection data of gas after combustion of different types of diesel and maintenance products are obtained, and the performance condition of a vehicle post-processing system is synthesized, so that the quality of different types of diesel, diesel maintenance products and vehicle urea solutions is evaluated.

Description

TECHNICAL FIELD

[0001] The utility model relates to a gas detection equipment, especially a diesel engine tail gas emission simulation and detection equipment. BACKGROUND

[0002] In order to reduce the influence of emission pollutants on atmospheric environment, major diesel engine manufacturers have carried out research on tail gas treatment.

[0003] The mainstream scheme of diesel engine tail gas aftertreatment is oxidation type catalyst (DOC) plus wall flow type particle trap (DPF) plus selective catalytic reduction (SCR) plus ammonia gas oxidation catalyst (ASC). Among them, DOC mainly treats hydrocarbons, nitrogen monoxide and soluble organic substances in particulate matter; DPF mainly treats particulate emissions generated by diesel combustion; SCR catalytically reduces nitrogen oxides by spraying urea water solution; and ASC treats unreacted ammonia gas escaping from SCR through catalytic oxidation.

[0004] Although the above-mentioned tail gas treatment technology can reduce emission pollutants to within the emission regulation limit, but due to the uneven quality of diesel or urea, engine aftertreatment loss and other reasons, there will still be emission exceeding the standard and engine torque limiting. Specifically, the use of inferior diesel, inferior urea water solution for vehicles or non-compliant maintenance products will cause damage to the engine, these products will reduce the activity of DOC and SCR catalysts, cause rapid clogging of DPF and other problems, thereby increasing the operation and maintenance cost of the engine, and even damaging the engine, causing serious loss. SUMMARY

[0005] The utility model aims at providing a diesel engine tail gas emission simulation and detection equipment for judging the quality of various vehicle chemicals, especially diesel and urea.

[0006] Technical scheme: the diesel engine tail gas emission simulation and detection equipment disclosed by the utility model comprises engine working simulation devices, gas treatment devices and ammonia gas absorption devices connected in sequence, the gas treatment device comprises oxidation type catalysts, wall flow type particle traps and selective catalytic reduction devices connected in sequence; a gas sensor one is arranged between the engine working simulation device and the gas treatment device; and a density concentration detection device is arranged in the ammonia gas absorption device.

[0007] By changing different diesel or maintenance products, comparing the detection data of the gas sensor, and according to the content of CO, SO2, HC, NOx, PN in the gas discharged by the engine working simulation device and the content of ash in the wall flow type particle trap, the quality of different types of diesel or maintenance products and their effects on the vehicle aftertreatment system can be compared and evaluated; according to the internal fouling of the selective catalytic reduction device and the ammonia concentration detected by the ammonia gas absorption device, the fouling and plugging risk, consumption and selective catalytic reduction ability of different types of vehicle urea solution can be compared and evaluated.

[0008] The engine working simulation device comprises an air inlet pipe, and a flow regulating valve is installed on the air inlet pipe. By controlling the flow regulating valve, the air intake amount can be changed to simulate different working conditions of the vehicle.

[0009] The engine working simulation device and the gas treatment device are connected by a pipeline, and the gas sensor is installed on the pipeline. A gas flow meter and at least one thermometer are also installed on the pipeline. The gas flow meter is used to obtain the gas discharge amount and temperature of the engine working simulation device.

[0010] The rear end of the oxidation catalyst and / or the rear end of the selective catalytic reduction device are provided with a gas sensor, a gas flow meter and a thermometer. The above-mentioned gas sensor, gas flow meter and thermometer are used to detect the gas composition, gas discharge amount and gas temperature corresponding to the gas treatment stage, which is helpful for comprehensive evaluation of the quality of various automobile chemicals such as diesel and urea.

[0011] The rear end of the wall flow type particle trap is provided with a gas sensor, and the front end of the selective catalytic reduction device is provided with a urea nozzle with adjustable flow. The urea nozzle is connected with a urea pump. According to the nitrogen oxide concentration measured by the above-mentioned gas sensor, the amount of urea sprayed by the urea nozzle is automatically or manually adjusted to adjust the reduction reaction of nitrogen oxides in the selective catalytic reduction device.

[0012] The ammonia gas absorption device further comprises a water inlet and a liquid level meter. The water inlet is used to introduce water to absorb the ammonia gas discharged by the selective catalytic reduction device, and the liquid level meter is used to monitor the water intake amount. The density concentration detection device can detect the ammonia concentration in the water.

[0013] The engine working simulation device comprises an igniter, a feeding area and a discharging area. The feeding area is used to introduce the material to be tested, the igniter is used to ignite the material to be tested, and the discharging area is used to discharge the waste residue of the material.

[0014] Beneficial effects: compared with the prior art, the utility model has the advantages that: 1, not only can realize the quality detection and evaluation of diesel and diesel maintenance products, but also can realize the detection and evaluation of urea quality;2, the detection device is arranged in each stage of gas treatment, comprehensive and accurate monitoring data can be obtained, thereby the diesel product is comprehensively evaluated;3, different working conditions of diesel engine can be simulated, and the test result has strong reference value. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0016] The technical scheme of the utility model will be further described below with reference to the drawings.

[0017] As Figure 1 shown, the utility model discloses a diesel engine exhaust emission simulation and detection equipment, including engine working simulation device 1, gas treatment device 2 and ammonia gas absorption device 3 that are connected in sequence.

[0018] Engine working simulation device 1 includes igniter 11, feed zone 12, discharge zone 13, air inlet pipe 102, ocular lens 14, feed zone 12 is used to introduce the material to be measured, igniter 11 is used to ignite the material to be measured, discharge zone 13 is used to discharge material waste residue, and flow regulating valve 103 and gas flow meter one are installed on air inlet pipe 102.

[0019] Engine working simulation device 1 and gas treatment device 2 are connected through a pipeline, and gas sensor one 101, gas flow meter one 104 and thermometer one 105 are installed on the pipeline.

[0020] Gas treatment device 2 includes oxidation type catalyst 21, wall flow type particle trap 22 and selective catalytic reduction device 23 that are connected in sequence. The rear end of oxidation type catalyst 21 is provided with gas sensor two 201, gas flow meter two 202 and thermometer two 203; the rear end of wall flow type particle trap 22 is provided with gas sensor four 207; the front end of selective catalytic reduction device 23 is provided with urea nozzle 208 with adjustable flow, and the rear end of selective catalytic reduction device 23 is provided with gas sensor three 204, gas flow meter three 205 and thermometer three 206.

[0021] Ammonia gas absorption device 3 includes density concentration detection device 31, water inlet 32, liquid level meter 33, gas outlet 34 and liquid outlet 35. Water inlet 32 is used to introduce water to absorb ammonia gas discharged by selective catalytic reduction device 23, liquid level meter 33 is used to monitor water inflow, density concentration detection device 31 can detect ammonia concentration in water, the remaining gas is discharged from gas outlet 34, and liquid is discharged from liquid outlet 35 after detection is completed.

[0022] Specifically, the material to be tested is introduced from the feeding area 12 of the engine working simulation device 1, air is introduced to participate in combustion through the air inlet pipe 102, the material is ignited by the igniter 11, the air inlet flow is adjusted by the flow adjusting valve 103 and the gas flow meter installed on the air inlet pipe 102, so as to simulate different working conditions of the engine. The gas after combustion enters the oxidation type catalyst 21 through the pipeline, and the composition, flow and temperature of the gas directly generated by the combustion of the material are monitored by the gas sensor 1 101, the gas flow meter 1 104 and the thermometer 1 105 arranged on the pipeline. The oxidation type catalyst 21 converts carbon monoxide (CO) and hydrocarbons (HC) in the gas into water (H2O) and carbon dioxide (CO2), and the converted gas enters the wall flow type particle trap 22. The gas sensor 2 201, the gas flow meter 2 202 and the thermometer 2 203 installed at the rear end of the oxidation type catalyst 21 record the composition, flow and temperature of the gas after being processed by the oxidation type catalyst 21. The wall flow type particle trap 22 traps carbon particles in the gas to remove most of the carbon particle pollutants. The gas sensor 4 207 at the rear end of the wall flow type particle trap 22 detects the concentration of nitrogen oxides (NOx) in the gas after being processed by the wall flow type particle trap 22, the urea injection amount of the urea nozzle 208 is adjusted according to the monitoring data of the gas sensor 4 207, the selective catalytic reducer 23 reduces the NOx in the gas after being processed by the wall flow type particle trap 22, and the composition data, flow and temperature of the gas after the reaction are detected by the gas sensor 3 204, the gas flow meter 3 205 and the thermometer 3 206. Open the exhaust port 34 of the ammonia gas absorption device 3, introduce water through the water inlet 32, and use the liquid level meter 33 to monitor the water inlet amount. The reduced gas enters the ammonia gas absorption device 3, where the ammonia is absorbed by water, and the ammonia concentration in the water is detected by the density concentration detection device 31. The remaining gas is discharged into the atmosphere through the exhaust port 34. After the material combustion is completed, the exhaust device of the engine working simulation device 1 is opened, the flow adjusting valve 103 is closed, the residual material waste is discharged through the discharging area 13, and the waste water in the device is discharged through the liquid outlet 35 of the ammonia gas absorption device 3.

[0023] By controlling the flow adjusting valve 103 to change the air inlet amount, different working conditions of the vehicle are simulated; by replacing different fuels or fuel maintenance products, the composition data of the gas sensor 1 101 are compared, the content of CO, SO2, HC, NOx, PN and other components is compared, the ash content in the wall flow type particle trap 22 is compared, and the influence of different types of fuel related chemicals on the vehicle aftertreatment system is evaluated; according to the internal fouling of the urea nozzle 208 and the selective catalytic reducer 23, the content of NOx and PN in the gas sensor 4 207, and the concentration of the absorption water in the ammonia gas absorption device, the fouling and blocking risk, the consumption amount and the selective catalytic reduction ability of different types of vehicle urea solution are compared.

[0024] Through the utility model, different brands and different types of diesel and maintenance products and different brands and different types of vehicle urea and various post-processing related maintenance products can be simulated to run the experiment, the practicability of different products on the market is evaluated, and example data and reference are provided for the practicability of diesel engine chemicals.

Claims

1. An apparatus for simulating and detecting exhaust emissions of a diesel engine, characterized by, The engine operation simulation device (1), the gas treatment device (2) and the ammonia absorption device (3) are sequentially connected, the gas treatment device (2) comprises an oxidation catalyst (21), a wall flow particle trap (22) and a selective catalytic reduction device (23) which are sequentially connected; a gas sensor (101) is arranged between the engine operation simulation device (1) and the gas treatment device (2); a density concentration detection device (31) is arranged in the ammonia absorption device (3).

2. The diesel engine exhaust emission simulation and detection apparatus according to claim 1, characterized by, The engine operation simulation device (1) comprises an air inlet pipe (102) on which a flow regulating valve (103) is installed.

3. The diesel engine exhaust emission simulation and detection apparatus according to claim 1, wherein The engine operation simulation device (1) and the gas treatment device (2) are connected through a pipeline, the gas sensor (101) is installed on the pipeline, and a gas flow meter (104) and at least one temperature meter (105) are also installed on the pipeline.

4. The diesel engine exhaust emission simulation and detection apparatus according to claim 1 or 3, characterized by, A gas sensor (201), a gas flow meter (202) and a temperature meter (203) are installed at the rear end of the oxidation catalyst (21), and / or a gas sensor (204), a gas flow meter (205) and a temperature meter (206) are installed at the rear end of the selective catalytic reduction device (23).

5. The diesel engine exhaust emission simulation and detection apparatus according to claim 1, wherein A gas sensor (207) is installed at the rear end of the wall flow particle trap (22), and a flow-adjustable urea nozzle (208) is installed at the front end of the selective catalytic reduction device (23).

6. The diesel engine exhaust emission simulation and detection apparatus according to claim 1, wherein The ammonia absorption device (3) further comprises a water inlet (32) for introducing water to absorb the ammonia gas discharged by the selective catalytic reduction device (23), and a liquid level meter (33) for monitoring the water inlet amount, and the density concentration detection device (31) can detect the ammonia concentration in the water.

7. The diesel engine exhaust emission simulation and detection apparatus according to claim 1, wherein The engine operation simulation device (1) comprises an igniter (11), a feed zone (12) and a discharge zone (13), the feed zone (12) is used to introduce the material to be tested, the igniter (11) is used to ignite the material to be tested, and the discharge zone (13) is used to discharge the material waste.

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