Marine diesel engine exhaust SCR denitrification system test device and test method

Abstract

The invention discloses a test device and a test method for a marine diesel engine exhaust SCR denitration system. The device comprises an input exhaust test straight pipe and a post-denitration exhaust test straight pipe, and a supercharger exhaust pipe is sequentially connected to the input exhaust test straight pipe, the exhaust SCR denitration system and the post-denitration exhaust test straight pipe. The input exhaust test straight pipe and the post-denitration exhaust test straight pipe are respectively connected to an emission analyzer through a sample suction pipe. The input exhaust test straight pipe and the post-denitration exhaust test straight pipe are respectively connected to a temperature sensor, a pressure sensor and a NOX sensor. The test method comprises 1) performing load condition tests according to proportional loads, 2) the emission analyzer measures exhaust emission data before and after denitration of the marine diesel engine, and 3) determining whether the requirements of emission regulations are met. The invention can quickly and effectively test the matching performance of the marine diesel engine and the SCR, thereby ensuring that the exhaust emissions of the marine diesel engine meet the relevant regulatory requirements of the International Maritime Organization.

Description

Technical Field

[0001] The invention relates to a test device for marine diesel engine exhaust, which is used to detect whether a marine diesel engine exhaust SCR denitration system meets the latest emission regulations, and also relates to a test method for a marine diesel engine exhaust SCR denitration system, belonging to the technical field of internal combustion engine exhaust post-processing test. Background Art

[0002] In recent years, with the mandatory implementation of the International Maritime Organization's Tier III emission regulations, more and more marine diesel engines have begun to be equipped with exhaust SCR (catalytic reduction) denitrification devices to reduce exhaust pollution, thereby meeting the latest emission regulations of the International Maritime Organization. However, the matching of existing marine diesel engines and SCR is uneven, and often cannot meet the relevant foreign inspection requirements of classification societies. The matching of SCR denitrification devices and marine diesel engines directly determines the performance of marine diesel engines, and also affects the exhaust emission effects of marine diesel engines. At present, the testing of marine diesel engines equipped with exhaust SCR denitrification devices mainly relies on third-party testing organizations. The test device has a complex structure, and the assembly and disassembly is time-consuming and labor-intensive. The test method is cumbersome and has poor reliability. Summary of the invention

[0003] The purpose of the present invention is to provide a test device and a test method for a marine diesel engine exhaust SCR denitration system with a simple structure and reliable testing, which can quickly and effectively test the matching performance of the marine diesel engine and the SCR.

[0004] The present invention is achieved through the following technical solutions:

[0005] A test device for a marine diesel engine exhaust gas SCR denitration system comprises an input exhaust gas test straight pipe and a post-denitration exhaust gas test straight pipe, wherein the turbocharger exhaust pipe of the marine diesel engine is connected to the input end of the exhaust gas SCR denitration system through the input exhaust gas test straight pipe, and the output end of the exhaust gas SCR denitration system is connected to the post-denitration exhaust gas test straight pipe; a first test pipe is vertically connected to the input end of the input exhaust gas test straight pipe, and a second test pipe is vertically connected to the discharge end of the post-denitration exhaust gas test straight pipe; the first test pipe and the second test pipe are also respectively connected to an emission analyzer through a sample suction pipe; the input exhaust gas test straight pipe is respectively connected to the exhaust gas test straight pipe; and the exhaust gas test straight pipe is connected to the exhaust gas test straight pipe. The first temperature sensor, the first pressure sensor and the first NOx sensor are connected; the exhaust gas test straight pipe after denitration is connected to the second temperature sensor, the second pressure sensor, the second NOx sensor and the ammonia test sensor respectively; the exhaust gas SCR denitration system is connected to the mass flowmeter; the signal lines of each temperature sensor, pressure sensor and NOx sensor, as well as the signal lines of the ammonia test sensor, the mass flowmeter and the diesel engine load signal sensor arranged on the marine diesel engine are respectively connected to the corresponding channels of the PLC monitoring device; the upper computer is connected to the PLC monitoring device through Ethernet communication.

[0006] The purpose of the present invention is further achieved by the following technical solutions:

[0007] Furthermore, the diameter D1 of the exhaust gas test straight pipe section and the diameter D2 of the exhaust gas test straight pipe after denitration are both larger than the diameter d of the turbocharger outlet pipe of the marine diesel engine.

[0008] Furthermore, the ratio of the distance L1 from the center of the first measuring tube to the input port of the exhaust gas SCR denitrification system to the diameter d1 of the first measuring tube is: L1 / d1>5, and the ratio of the distance L2 from the output end of the exhaust gas SCR denitrification system to the center of the second measuring tube to the diameter d2 of the second measuring tube is: L2 / d2>10.

[0009] Furthermore, the temperature measurement ranges of the first and second temperature sensors are both 0~600°C, the pressure measurement ranges of the first pressure sensor and the second pressure sensor are both 0~200mbar, the test ranges of the first NOx sensor and the second NOx sensor are both 0~2000ppm, and the test range of the ammonia sensor is 0~100ppm.

[0010] A test method for a test device for a marine diesel engine exhaust SCR denitration system is performed according to the following test requirements and steps:

[0011] 1) Carry out load condition tests according to proportional loads. After the marine diesel engine has been running stably for more than 20 minutes, first carry out a load condition test of 100% of the rated power of the marine diesel engine, and then carry out load condition tests according to proportional loads of 75%, 50%, 25% and 10% of the rated power of the marine diesel engine;

[0012] 2) In each proportional load condition test, the exhaust emission data of the marine diesel engine before and after denitration are measured by the emission analyzer, and the exhaust emission data are compared and analyzed by the PLC monitoring device. The NOx data of the first NOx sensor before the input end of the exhaust SCR denitration system and the second NOx sensor after the output end of the exhaust SCR denitration system are collected respectively to analyze the change of NOx emissions; at the same time, the input end temperature of the exhaust SCR denitration system detected by the first temperature sensor and the output end temperature of the exhaust SCR denitration system detected by the second temperature sensor, the input end pressure of the exhaust SCR denitration system detected by the first pressure sensor and the output end pressure of the exhaust SCR denitration system detected by the second pressure sensor are collected respectively, and the difference between the input end pressure and the output end pressure is the pressure loss; the difference between the ammonia amount at the input end of the exhaust SCR denitration system detected by the first NOx sensor and the ammonia amount at the output end of the exhaust SCR denitration system detected by the second NOx sensor is the ammonia slip; the mass flow meter detects the urea injection amount of the exhaust SCR denitration system;

[0013] 3) The PLC monitoring device uses a weighted method to calculate the denitrification efficiency of the exhaust SCR denitrification system under each operating condition based on the above collected data to determine whether it meets the requirements of the International Maritime Organization's Tier III emission regulations, thereby completing the test of the exhaust emission effect of marine diesel engines.

[0014] Furthermore, the recommended reaction temperature of the exhaust gas SCR denitrification system in step 3) is 260-530°C; the pressure difference between the input and output ends of the exhaust gas SCR denitrification system does not exceed 30mbar, and the ammonia slip of the difference between the ammonia volume at the input end and the ammonia volume at the output end of the exhaust gas SCR denitrification system does not exceed 10PPm.

[0015] The present invention respectively sets an exhaust gas input test straight pipe and a post-denitration exhaust gas test straight pipe at both ends of the exhaust gas SCR denitration system of the marine diesel engine, and detects the corresponding data before and after the exhaust gas treatment through the corresponding temperature sensor, pressure sensor and NOX sensor, and then processes the above-collected data through the PLC monitoring device. The structure is simple and compact, and can quickly and effectively test the matching performance of the marine diesel engine and the SCR, so as to promote the performance matching of the marine diesel engine and the exhaust gas SCR denitration system to meet the requirements, thereby ensuring that the exhaust gas emissions of the marine diesel engine meet the relevant regulatory requirements of the International Maritime Organization.

[0016] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a test device for a marine diesel engine exhaust SCR denitration system of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] like Figure 1As shown, the test device for the exhaust SCR denitration system of a marine diesel engine of the present invention comprises an input exhaust test straight pipe 1 and a post-denitration exhaust test straight pipe 2. The turbocharger exhaust pipe 101 of the marine diesel engine 100 is connected to the input end of the exhaust SCR denitration system 20 through the input exhaust test straight pipe 1, and the output end of the exhaust SCR denitration system 20 is connected to the post-denitration exhaust test straight pipe 2. The first test pipe 11 is vertically connected to the input end of the input exhaust test straight pipe 1, and the second test pipe 21 is vertically connected to the discharge end of the post-denitration exhaust test straight pipe 2. The first test pipe 11 and the second test pipe 12 are also respectively connected to the emission analyzer 4 through the sample suction pipe 3. The input exhaust test straight pipe 1 is respectively connected to the first temperature sensor 51, the first pressure sensor 61 and the first NOx sensor 71, the post-denitration exhaust test straight pipe 2 is respectively connected to the second temperature sensor 52, the second pressure sensor 62, the second NOx sensor 72 and the ammonia test sensor 8, and the exhaust SCR denitration system 20 is connected to the mass flowmeter 201. The signal lines 301 of each temperature sensor, pressure sensor and NOx sensor, as well as the signal lines 301 of the ammonia test sensor 8, the mass flow meter 9 and the diesel engine load signal sensor arranged on the marine diesel engine are respectively connected to the corresponding channels of the PLC monitoring device 30; the host computer 40 is connected to the PLC monitoring device 30 via Ethernet communication.

[0020] The diameter D1 of the exhaust test straight pipe section and the diameter D2 of the exhaust test straight pipe after denitration are both larger than the diameter d of the turbocharger outlet pipe of the marine diesel engine 100. The ratio of the distance L1 from the center of the first test pipe 11 to the input port of the exhaust SCR denitration system 20 to the diameter d1 of the first test pipe is: L1 / d1>5, and the ratio of the distance L2 from the output end of the exhaust SCR denitration system 20 to the center of the second test pipe 21 to the diameter d2 of the second test pipe 21 is: L2 / d2>10.

[0021] The temperature measuring ranges of the first temperature sensor 51 and the second temperature sensor 52 are both 0-600°C, the pressure measuring ranges of the first pressure sensor 61 and the second pressure sensor 62 are both 0-200 mbar, the test ranges of the first NOx sensor 71 and the second NOx sensor 72 are both 0-2000 ppm, and the test range of the ammonia sensor 8 is 0-100 ppm.

[0022] The test method of the marine diesel engine exhaust SCR denitrification system test device is carried out according to the following test requirements and steps:

[0023] 1) Carry out load condition tests respectively according to proportional loads. After the marine diesel engine 100 has been running stably for more than 20 minutes, first carry out a load condition test of 100% of the rated power of the marine diesel engine 100. Then, carry out load condition tests respectively according to proportional loads of 75%, 50%, 25% and 10% of the rated power of the marine diesel engine 100.

[0024] 2) In each proportional load condition test, the exhaust emission data of the marine diesel engine 100 before and after denitration are measured by the emission analyzer 4, and the exhaust emission data are compared and analyzed by the PLC monitoring device 30, and the NOx data of the first NOx sensor 71 before the input end of the exhaust SCR denitration system 20 and the second NOx sensor 72 after the output end of the exhaust SCR denitration system 20 are collected respectively to analyze the change of NOx emissions; at the same time, the input end temperature of the exhaust SCR denitration system 20 detected by the first temperature sensor 51 and the output end temperature of the exhaust SCR denitration system 20 detected by the second temperature sensor 52, the input end pressure of the exhaust SCR denitration system 20 detected by the first pressure sensor 51 and the output end pressure of the exhaust SCR denitration system 20 detected by the second pressure sensor 52 are collected respectively, and the difference between the input end pressure and the output end pressure is the pressure loss. The difference between the ammonia amount at the input end of the exhaust SCR denitration system 20 detected by the first NOx sensor 71 and the ammonia amount at the output end of the exhaust SCR denitration system 20 detected by the second NOx sensor 72 is the ammonia slip amount.

[0025] 3) The PLC monitoring device 30 calculates the denitration efficiency of the exhaust SCR denitration system 20 under each operating condition using a weighted method for the above-collected data to determine whether the requirements of the International Maritime Organization's Tier III emission regulations are met, thereby completing the test of the exhaust emission effect of the marine diesel engine.

[0026] In step 3), the recommended reaction temperature of the exhaust gas SCR denitration system 20 is 260-530°C; the pressure difference between the input end and the output end of the exhaust gas SCR denitration system 20 does not exceed 30mbar, and the ammonia slip of the difference between the ammonia amount at the input end and the ammonia amount at the output end of the exhaust gas SCR denitration system 20 does not exceed 10PPm.

[0027] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A test method for a test device for a marine diesel engine exhaust gas SCR denitration system, the test device comprising an exhaust gas input test straight pipe and a denitration exhaust gas test straight pipe, the turbocharger exhaust pipe of the marine diesel engine is connected to the input end of the exhaust gas SCR denitration system through the exhaust gas input test straight pipe, the output end of the exhaust gas SCR denitration system is connected to the denitration exhaust gas test straight pipe; a first test pipe is vertically connected to the input end of the exhaust gas input test straight pipe, and a second test pipe is vertically connected to the discharge end of the denitration exhaust gas test straight pipe; the first test pipe and the second test pipe are also respectively connected to an emission analyzer through a sample suction pipe; the exhaust gas input test straight pipe is connected to the exhaust gas input test straight pipe, and the exhaust gas output end is connected to the exhaust gas output test straight pipe; the exhaust gas input test straight pipe is connected to the exhaust gas output ... The first temperature sensor, the first pressure sensor and the first NOX sensor are connected in parallel respectively; the exhaust gas test straight pipe after denitration is connected in parallel to the second temperature sensor, the second pressure sensor, the second NOX sensor and the ammonia test sensor respectively; the exhaust gas SCR denitration system is connected in parallel to the mass flowmeter; the signal lines of each temperature sensor, pressure sensor and NOX sensor, as well as the signal lines of the ammonia test sensor, the mass flowmeter and the diesel engine load signal sensor arranged on the marine diesel engine are connected to the corresponding channels of the PLC monitoring device respectively; the upper computer is connected to the PLC monitoring device through Ethernet communication; it is characterized in that: Perform the test according to the following test requirements and steps: Step 1) performing load condition tests respectively according to proportional loads, after the marine diesel engine has been running stably for more than 20 minutes, firstly performing a load condition test of 100% of the rated power of the marine diesel engine, and then performing load condition tests respectively according to proportional loads of 75%, 50%, 25% and 10% of the rated power of the marine diesel engine; Step 2) In each proportional load condition test, the exhaust emission data of the marine diesel engine before and after denitration are measured by the emission analyzer, and the exhaust emission data are compared and analyzed by the PLC monitoring device, and the NOx data of the first NOx sensor before the input end of the exhaust SCR denitration system and the second NOx sensor after the output end of the exhaust SCR denitration system are collected respectively, and the change of NOx emission is analyzed; at the same time, the input end temperature of the exhaust SCR denitration system detected by the first temperature sensor and the output end temperature of the exhaust SCR denitration system detected by the second temperature sensor, the input end pressure of the exhaust SCR denitration system detected by the first pressure sensor and the output end pressure of the exhaust SCR denitration system detected by the second pressure sensor are collected respectively, and the difference between the input end pressure and the output end pressure is the pressure loss; The difference between the amount of ammonia at the input end of the exhaust SCR denitration system detected by the first NOX sensor and the amount of ammonia at the output end of the exhaust SCR denitration system detected by the second NOX sensor is the ammonia slip amount; the mass flow meter detects the urea injection amount of the exhaust SCR denitration system; Step 3) The PLC monitoring device calculates the denitrification efficiency of the exhaust SCR denitrification system under each operating condition using a weighted method for the above-collected data to determine whether the requirements of the International Maritime Organization's Tier III emission regulations are met, thereby completing the test of the exhaust emission effect of the marine diesel engine.

2. The testing method of the marine diesel engine exhaust SCR denitration system testing device according to claim 1, characterized in that: The diameter D1 of the test straight pipe section and the diameter D2 of the test straight pipe after denitration are both larger than the diameter d of the turbocharger outlet pipe of the marine diesel engine.

3. The testing method of the marine diesel engine exhaust SCR denitration system testing device according to claim 1, characterized in that: The ratio of the distance L1 from the center of the first measuring tube to the input port of the exhaust gas SCR denitrification system to the diameter d1 of the first measuring tube is: L1 / d1>5, and the ratio of the distance L2 from the output end of the exhaust gas SCR denitrification system to the center of the second measuring tube to the diameter d2 of the second measuring tube is: L2 / d2>10.

4. The testing method of the marine diesel engine exhaust SCR denitration system testing device according to claim 1, characterized in that: The temperature measurement ranges of the first temperature sensor and the second temperature sensor are both 0-600°C, the pressure measurement ranges of the first pressure sensor and the second pressure sensor are both 0-200mbar, the test ranges of the first NOx sensor and the second NOx sensor are both 0-2000ppm, and the test range of the ammonia sensor is 0-100ppm.

5. The testing method of the marine diesel engine exhaust SCR denitration system testing device according to claim 1, characterized in that: The recommended reaction temperature of the exhaust gas SCR denitrification system in step 3) is 260-530°C; the pressure difference between the input end and the output end of the exhaust gas SCR denitrification system does not exceed 30mbar, and the ammonia slip of the difference between the ammonia amount at the input end and the ammonia amount at the output end of the exhaust gas SCR denitrification system does not exceed 10PPm.

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