Centralized purification device for tail gas of diesel engine test bed

Abstract

The utility model discloses a tail gas centralized purification device for a diesel engine test bed. The tail gas centralized purification device comprises a gas collection pipeline, an electric heating diesel particulate filter, an atomized water filter device, a tail gas bypass system and a control system. Tail gas of the multiple engines is collected in a centralized mode through the gas collecting pipeline, purified through the electric heating diesel particulate filter and the atomization water filtering device in sequence and then exhausted through the exhaust funnel. Particulate matters and sulfides in the tail gas are respectively removed by the electric heating diesel particulate filter and the atomized water filtering device. The tail gas bypass system can reduce the resistance of the purification device under special working conditions such as regeneration. The control system automatically adjusts regeneration of the electric heating diesel particulate filter, pollution discharge and liquid supplement of the atomized water filter device and the like. The device achieves centralized purification and modular design, is high in automation degree, and can remarkably improve the tail gas purification efficiency of multiple diesel engine test beds.

Description

Technical Field

[0001] The utility model relates to the technical field of after-treatment of tail gas of an internal combustion engine, and in particular to a centralized tail gas purification device of a diesel engine test bench. Background Art

[0002] Diesel engines are widely used in transportation, construction machinery, agricultural equipment and other fields due to their good power, economy and reliability. In order to further improve the performance of diesel engines, they need to be tested and optimized on the test bench. During the test, diesel engines will produce a large amount of exhaust gas containing particulate matter, sulfide and other harmful substances. If they are directly discharged, they will cause serious pollution to the environment.

[0003] At present, the common practice for exhaust gas treatment on diesel engine test benches is to equip each engine with an independent purification device. This "one machine, one purification" model has the following problems: first, each purification device contains components such as DPF, catalytic converter, and selective catalytic reduction device, resulting in equipment duplication and cost waste; second, multiple purification devices work in parallel, occupying a large area, which is not conducive to the compact layout of the test bench; third, each purification device needs to be maintained separately, which is labor-intensive and has high operation and maintenance costs.

[0004] In order to solve the above problems, it is necessary to develop a centralized exhaust purification device for diesel engine test benches, which can collect and process the exhaust gas from multiple engines. Through modular design, the centralized layout and unified maintenance of purification equipment can be realized, which can improve equipment utilization, save site space, and reduce operation and maintenance costs. At the same time, the centralized purification device should have efficient particle capture and sulfide absorption capabilities, and be able to adapt to changes in operating conditions during engine testing. In addition, it is also necessary to solve the regeneration problem of the centralized purification device and reduce system resistance. Utility Model Content

[0005] In order to solve the problems of the prior art, the embodiment of the utility model provides a centralized exhaust gas purification device for a diesel engine test bench. The technical solution is as follows:

[0006] On the one hand, a centralized exhaust gas purification device for a diesel engine test bench is provided, comprising an air collecting pipeline, an electrically heated diesel particulate filter (DPF), an atomizing water filter device, an exhaust gas bypass system and a control system connected in sequence; the air collecting pipeline is used to collect and introduce exhaust gas from multiple diesel engines into the purification device; the electrically heated DPF is used to capture and oxidize particulate matter in the exhaust gas; the atomizing water filter device is used to absorb sulfides in the exhaust gas; the exhaust gas bypass system is used to adjust the direction of exhaust gas flow; the control system is electrically connected to the electrically heated DPF, the atomizing water filter device and the exhaust gas bypass system.

[0007] Furthermore, the gas collecting pipeline is made of high temperature resistant stainless steel, and is provided with vibration isolation and thermal expansion compensation devices, and the pipeline diameter is determined by calculation based on the number and displacement of engines.

[0008] Furthermore, the electrically heated DPF comprises a honeycomb cordierite ceramic substrate, a rare earth catalyst coating coated on the inside of the ceramic substrate, and a high temperature resistant electric heating belt wound around the outside of the ceramic substrate.

[0009] Furthermore, the atomizing water filter device is made of stainless steel, is internally provided with a high-pressure atomizing nozzle and a baffle, and has a sewage outlet and a liquid level control device at the bottom of the device.

[0010] Furthermore, the exhaust gas bypass system includes a pneumatic high-temperature butterfly valve arranged on the gas collecting pipeline.

[0011] Furthermore, the control system includes a PLC controller, a differential pressure sensor, a temperature sensor and a liquid level sensor electrically connected to the PLC controller.

[0012] Furthermore, the atomization particle size of the high-pressure atomization nozzle is 2-5 microns.

[0013] Furthermore, the purified liquid in the atomized water filter device is an alkaline solution.

[0014] The beneficial effects brought by the technical solution provided by the embodiment of the utility model are:

[0015] The diesel engine test bench exhaust centralized purification device provided by the utility model has the following beneficial effects:

[0016] 1. Centralized purification and high equipment utilization: The exhaust gas from multiple diesel engines is collected and purified uniformly, which reduces the number and types of purification equipment, improves equipment utilization and saves capital investment.

[0017] 2. Modular design and flexible layout: Adopting the modular design concept, various functional components can be flexibly combined according to actual needs, which facilitates the realization of compact layout and saves site space.

[0018] 3. Electric heating regeneration, high degree of automation: The electric heating DPF has an automatic regeneration function, which burns the captured soot particles through electric heating, avoiding DPF blockage and reducing maintenance workload. The regeneration process is automatically managed by the control system, which greatly improves the automation level of the system.

[0019] 4. Atomization absorption, high purification efficiency: The atomization water filter device atomizes the absorption liquid into fine droplets, which are fully mixed with the tail gas, greatly improving the absorption efficiency of sulfides. The built-in baffles extend the tail gas residence time and further enhance the purification effect.

[0020] 5. Bypass control to protect the engine: The pneumatic high-temperature butterfly valve installed on the gas collection pipeline can introduce the exhaust gas into the bypass under special working conditions such as DPF regeneration, reduce the resistance of the purification device, and avoid affecting the engine performance.

[0021] 6. Vibration isolation, adaptable to harsh environment: Vibration isolation and thermal expansion compensation devices are installed between the gas collection pipeline and the purification device to effectively reduce the impact of engine vibration on the purification device and improve system reliability.

[0022] 7. Fault diagnosis and convenient maintenance: The control system has a complete fault diagnosis function. Through the monitoring of parameters such as pressure difference, temperature, liquid level, etc., it can accurately judge the system operation status and promptly remind users to perform maintenance to ensure stable purification effect.

[0023] In summary, the centralized purification device provided by the utility model significantly improves the purification efficiency and automation level while reducing the number of purification equipment, prolongs the DPF life, reduces maintenance costs, and provides a set of efficient, reliable and economical solutions for exhaust gas treatment of multiple diesel engine test benches. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic diagram of a centralized exhaust gas purification device for a diesel engine test bench according to Embodiment 1 of the present utility model;

[0026] Figure 2 This is a schematic diagram of the electrically heated DPF and its control in Embodiment 1 of the present utility model;

[0027] Figure 3 This is a schematic diagram of the atomizing water filter device and its control in Example 1 of the utility model;

[0028] Figure 4 It is a schematic diagram of the gas collection pipeline and its vibration isolation / thermal expansion compensation device in Example 1 of the utility model. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clear, the implementation mode of the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] like Figure 1-4As shown, the utility model provides a centralized exhaust gas purification device for a diesel engine test bench, comprising an air collecting pipeline, an electrically heated diesel particulate filter (DPF), an atomizing water filter device, an exhaust gas bypass system and a control system which are connected in sequence.

[0032] The gas collection pipeline 1 is made of high temperature resistant stainless steel and is equipped with vibration isolation and thermal expansion compensation devices. The pipeline diameter is determined by the number and displacement of engines to be connected. The gas collection pipeline collects the exhaust gas of multiple diesel engines and guides it into the purification device.

[0033] The electric heating DPF includes a honeycomb cordierite ceramic matrix, a rare earth catalyst coating applied inside the ceramic matrix, and a high temperature resistant electric heating belt wrapped around the outside of the ceramic matrix. When the exhaust gas passes through the electric heating DPF, the particulate matter is trapped in the ceramic matrix and oxidized by the rare earth catalyst coating. The electric heating belt can heat the DPF to a temperature of more than 600°C, promoting the combustion and regeneration of the particulate matter.

[0034] The atomizing water filter device is made of stainless steel, with a high-pressure atomizing nozzle and a baffle inside, and a drain port and a liquid level control device at the bottom of the device. The high-pressure atomizing nozzle atomizes the purified liquid into fine droplets of 2-5 microns, which are fully mixed with the tail gas to absorb the sulfide in the tail gas. The baffle extends the flow path of the tail gas in the atomizing water filter device 3, improving the purification efficiency. The drain port and the liquid level control device are used to discharge waste liquid and replenish fresh purified liquid respectively.

[0035] The exhaust gas bypass system includes a pneumatic high-temperature butterfly valve installed on the gas collection pipeline. Under special working conditions such as DPF regeneration, the pneumatic high-temperature butterfly valve opens to allow the exhaust gas to partially or completely bypass the purification device, reducing system resistance.

[0036] The control system includes a PLC controller, a differential pressure sensor, a temperature sensor and a liquid level sensor electrically connected to the PLC controller. The PLC controller automatically controls the operating status of the electric heating belt, the pneumatic high-temperature butterfly valve and the atomizing water filter device according to the signals of each sensor.

[0037] The working process of this embodiment is as follows: the exhaust gas generated during the diesel engine test is first collected through the gas collection pipeline, then sequentially passed through the electrically heated DPF to remove particulate matter, the atomized water filter device absorbs sulfides, and finally discharged from the exhaust pipe. The control system determines whether regeneration is required based on the pressure difference, temperature and other parameters of the DPF, and controls the electric heating belt to heat the DPF when necessary. At the same time, according to the liquid level of the atomized water filter device and the purity of the purified liquid, the sewage outlet and the liquid level control device are controlled to discharge sewage and replenish liquid.

[0038] The diesel engine test bench exhaust centralized purification device provided in this embodiment centrally processes the exhaust of multiple engines, reduces the number of purification equipment, and saves floor space. The electric heating DPF can effectively remove particulate matter in the exhaust gas, and the atomizing water filter device can absorb sulfides. The combination of the two can significantly improve the exhaust gas purification effect. The electric heating regeneration and automatic control functions make the system operation more reliable and convenient.

[0039] Example 2

[0040] On the basis of Example 1, the purification liquid in the atomized water filter device is an alkaline solution, such as a sodium hydroxide solution or a potassium hydroxide solution. The alkaline solution can neutralize acidic substances such as sulfur dioxide in the tail gas, generate water-soluble compounds such as sodium sulfate, and improve the desulfurization efficiency.

[0041] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields, are also included in the patent protection scope of the utility model.

Claims

1. A diesel engine test bench exhaust centralized purification device, characterized in that: It includes an air collecting pipeline, an electrically heated diesel particulate filter, an atomizing water filter, an exhaust gas bypass system and a control system connected in sequence; the air collecting pipeline is used to collect the exhaust gas of multiple diesel engines and introduce it into the purification device; the electrically heated diesel particulate filter is used to capture and oxidize particulate matter in the exhaust gas; the atomizing water filter is used to absorb sulfides in the exhaust gas; the exhaust gas bypass system is used to adjust the exhaust gas flow direction; The control system is electrically connected to the electrically heated diesel particulate trap, the atomizing water filter device and the exhaust gas bypass system.

2. The diesel engine test bench exhaust centralized purification device according to claim 1, characterized in that: The gas collection pipeline is made of high temperature resistant stainless steel and is equipped with vibration isolation and thermal expansion compensation devices. The pipeline diameter is calculated and determined based on the number and displacement of engines.

3. The diesel engine test bench exhaust centralized purification device according to claim 1, characterized in that: The electrically heated diesel particulate filter comprises a honeycomb cordierite ceramic substrate, a rare earth catalyst coating coated inside the ceramic substrate, and a high-temperature resistant electric heating belt wound outside the ceramic substrate.

4. The diesel engine test bench exhaust centralized purification device according to claim 1, characterized in that: The atomizing water filter device is made of stainless steel, and is internally provided with a high-pressure atomizing nozzle and a baffle, and the bottom of the device is provided with a sewage outlet and a liquid level control device.

5. The diesel engine test bench exhaust centralized purification device according to claim 1, characterized in that: The tail gas bypass system includes a pneumatic high-temperature butterfly valve arranged on the gas collection pipeline.

6. The diesel engine test bench exhaust centralized purification device according to claim 1, characterized in that: The control system includes a PLC controller, a differential pressure sensor, a temperature sensor and a liquid level sensor electrically connected to the PLC controller.

7. The diesel engine test bench exhaust centralized purification device according to claim 4, characterized in that: The atomization particle size of the high-pressure atomization nozzle is 2-5 microns.

8. The diesel engine test bench exhaust centralized purification device according to claim 4, characterized in that: The purified liquid in the atomized water filter device is an alkaline solution.

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