A device and method for measuring ammonia emissions from an ammonia-hydrogen fuel engine

Abstract

This invention belongs to the field of exhaust gas monitoring technology and discloses a device and method for measuring ammonia emissions from an ammonia-hydrogen fuel cell engine. The device includes a high-efficiency filter and an engine. The high-efficiency filter is connected to an air heater. A first sampler is provided at the outlet of the air heater. The air heater and the engine are connected to a heating and mixing chamber. The heating and mixing chamber is connected to a dilution channel. The dilution channel is connected to a fan through a critical venturi tube. A sensor and a second sampler are provided in the dilution channel. The second sampler and the first sampler are connected to an analyzer. The analyzer and the sensor are connected to a computer. The method includes S1: connecting the measuring device; S2: preparation before measurement; S3: starting the measurement and acquiring parameters; S4: calculating the power-based emission factor of pollutants. This invention solves the problem of inaccurate measurement of ammonia emissions from engines in existing technologies and is applicable to exhaust gas measurement.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas monitoring technology, and in particular to a device and method for measuring ammonia emissions from an ammonia-hydrogen fuel engine. Background Technology

[0002] Hydrogen ammonia fuel is a new type of engine fuel because it has high energy density liquid ammonia and is a zero-carbon fuel, making it a substitute for traditional fuels.

[0003] The combustion of hydrogen ammonia fuel often results in the emission of NH3 pollutants. When measuring the pollutant emissions of hydrogen ammonia fuel engines, the NH3 emission sample is lost due to the water-soluble nature of NH3, leading to inaccurate measurement results. Summary of the Invention

[0004] The present invention aims to provide a device and method for measuring ammonia emissions from an ammonia-hydrogen fuel engine, in order to solve the problem of inaccurate measurement results of ammonia emissions from engines in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The basic technical solution provided by this invention is: a device and method for measuring ammonia emissions from an ammonia-hydrogen fuel engine, comprising an engine, an air filtration device, a mixing device, and a data acquisition device;

[0007] The air filtration system includes a high-efficiency filter, which is connected to an air heater. The air heater contains a device for removing NO from the air. x The catalyst; the mixing device includes a heated mixing chamber, which is connected to an engine, an air heater and a dilution channel respectively. The dilution channel is connected to a critical venturi tube, and the critical venturi tube is connected to a fan; the data acquisition device includes a sensor, a first sampler and a second sampler. The sensor includes a temperature sensor, a pressure sensor and a humidity sensor. The sensor and the second sampler are both located in the dilution channel. The first sampler is located at the outlet of the air heater. The first sampler and the second sampler are both connected to an analyzer. The analyzer and the sensor are both connected to a computer.

[0008] Furthermore, the catalyst is a transition metal silicon-oxygen tetrahedron.

[0009] Furthermore, both the air heater and the heating mixing chamber use resistance wires or burners as heating sources.

[0010] Furthermore, the temperature inside the air heater is 120°C.

[0011] Furthermore, the temperature inside the heating mixing chamber is not lower than 130°C.

[0012] Furthermore, the dilution channel adopts a short dilution channel design.

[0013] Furthermore, the distance between the sensor, the first sampler, and the second sampler and the inlet of the dilution channel is equal to five times the diameter of the dilution channel.

[0014] The present invention also provides a technical solution:

[0015] The method for measuring ammonia emissions using any of the above-mentioned ammonia emission measuring devices and methods for ammonia-hydrogen fuel engines includes the following steps:

[0016] S1: Connection of measuring device: Connect the high-efficiency filter to the air heater, connect the heating mixing chamber to the engine, air heater and dilution channel respectively, connect the critical venturi tube to the dilution channel and the fan respectively, place the first sampler at the outlet end of the air heater, place the sensor and the second sampler in the dilution channel, and the distance between the sensor and the second sampler and the inlet end of the dilution channel is 5 times the diameter of the dilution channel. Finally, connect the first sampler and the second sampler to the analyzer, and connect the analyzer and the sensor to the computer.

[0017] S2: Preparation before measurement: Turn on the fan. The fan, as a power source, draws the filtered air, which has passed through the high-efficiency filter and air heater, and the exhaust gas from the engine into the heating and mixing chamber for mixing. The mixed gas flows stably and continuously in the dilution channel. When the mixed gas flows through the throat of the critical venturi tube, the flow velocity of the mixed gas reaches the local speed of sound, thereby obtaining the critical flow rate V of the critical venturi tube.

[0018] S3: Start measuring and acquiring parameters: Obtain the pump pressure P of the fan. B Total cyclic power of the engine (W) cycle The temperature T in the dilution channel is collected using sensors. P Pressure P1 and absolute humidity H are measured. A sampler is used to collect air samples from the outlet of the air heater. The analyzer then analyzes the samples to obtain the water vapor concentration c of the filtered air. H2O,dil Concentration of pollutants C in filtered air d The second sampler is used to collect samples of the mixed gas in the dilution channel, and the analyzer analyzes the samples to obtain the water vapor concentration c of the mixed gas. H2O,exh The concentration of pollutants in the mixed gas C e The pollutant density ρ of the mixed gas i ;

[0019] S4: Calculate the work-based emission factor of pollutants: First, calculate the dilution ratio DF of the mixed gas in the dilution channel to the filtered gas after passing through the HEPA filter and air heater, and then use the dilution ratio DF to calculate the concentration C of the mixed gas in the dilution channel. eCorrections are made to prevent pollutants in the filtered air from affecting the measurement of pollutants in the engine exhaust, thus obtaining the corrected pollutant concentration C. i Then calculate the volume V of the mixed gas flowing through the dilution channel every 1 second. mix Humidity correction factor k for NH3 emissions H And based on the obtained C i V mix K H Calculate the mass m of pollutants in the exhaust gas at the i-th second in the dilution channel. i Finally, for m i By performing approximate integration, the power-based emission factor M of pollutants in engine exhaust is obtained. cycle This is used to determine the ammonia emissions of the ammonia-hydrogen fuel cell engine;

[0020] Calculate the dilution ratio DF:

[0021]

[0022] The concentration of pollutants C in the dilution channel was determined using the obtained dilution ratio DF. e Make corrections and obtain the corrected pollutant concentration C. i :

[0023]

[0024] Calculate the volume V of the mixed gas flowing through the dilution channel every 1 second. mix :

[0025]

[0026] Calculate the humidity correction factor k for NH3 emissions H :

[0027]

[0028] Based on the calculated C i V mix K H Calculate the mass m of pollutants in the exhaust gas at second i. i :

[0029] m i =V mix ×C i ×ρ i ×k H

[0030] The mass m of the pollutant per second during the experiment i By performing an approximate integral, the power-based emission factor M is obtained. cycle :

[0031]

[0032] In the formula c H2O,dil C d c represents the water vapor concentration and pollutant concentration at the outlet of the air heater, respectively. H2O,exh C e ρ i These represent the water vapor concentration, pollutant concentration, and pollutant density within the dilution channel, respectively, T. P P1, H, and V represent the temperature, mixed gas pressure, and absolute humidity measured by the sensor in the dilution channel, respectively. V is the critical flow rate of the critical venturi tube. B V is the pump pressure of the blower, DF is the dilution ratio of the mixed gas in the dilution channel to the filtered gas after passing through the high-efficiency filter and air heater, and V is the concentration of the pump pressure of the blower. mix To dilute the volume of gas flowing through the channel every 1 second, m i Let W be the mass of pollutants in the exhaust gas of the engine at the i-th second. cycle M is the total work done in a cycle of the engine. cycle It is the power-based emission factor of pollutants in engine exhaust.

[0033] The beneficial effects of the technical solution are:

[0034] 1. The filtered air, which has passed through a high-efficiency filter and an air heater, is heated by an air heater to keep the filtered air in a gaseous state. The engine exhaust is heated simultaneously by the filtered air and the heating mixing chamber. This ensures that the water and NH3 in the engine exhaust sample remain in a gaseous state throughout the measurement process, preventing condensation from absorbing NH3, effectively avoiding NH3 sample loss, and ensuring the accuracy of the test results.

[0035] 2. The engine exhaust remains in a gaseous state throughout the measurement process, ensuring that the measurement of engine pollutant emissions is not affected by the outside temperature, and thus the measurement results are convincing.

[0036] 3. The dilution channel of this invention adopts a short dilution channel design to reduce the heat dissipation of the mixed gas in the dilution channel. The molecular motion speed is increased in a high-energy state, which is conducive to the uniform mixing of pollutants in engine exhaust and ensures the accuracy of sample collection by the second sampler. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to the present invention;

[0038] The corresponding labels in the attached diagram are: Engine 1, High-efficiency filter 2, Air heater 3, Heated mixing chamber 4, Dilution channel 5, Computer 6, Sensor 7, First sampler 81, Second sampler 82, Analyzer 9, Critical venturi tube 10, Fan 11. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0040] like Figure 1 The following describes a device and method for measuring ammonia emissions from an ammonia-hydrogen fuel cell engine: a high-efficiency filter 2 and an engine 1. The high-efficiency filter 2 is connected to an air heater 3. The air heater 3 contains a silicon-oxygen tetrahedron catalyst. A first sampler 81 is located at the outlet of the air heater 3. Both the air heater 3 and the engine 1 are connected to a heating mixing chamber 4. Both the air heater 3 and the heating mixing chamber 4 use resistance wires or burners as heating sources. The temperature inside the air heater 3 is 120°C, and the temperature inside the heating mixing chamber 4 is not lower than 130°C. The heating mixing chamber 4 is connected to a dilution channel 5, which is designed as a short dilution channel. The dilution channel 5 is connected to a fan 11 via a critical venturi tube 10. A sensor 7 and a second sampler 82 are located inside the dilution channel 5. The distance between the sensor 7 and the inlet of the dilution channel 5 is equal to five times the diameter of the dilution channel 5. Both the second sampler 82 and the first sampler 81 are connected to an analyzer 9. Both the analyzer 9 and the sensor 7 are connected to a computer 6.

[0041] The method for measuring ammonia emissions using the aforementioned ammonia emission measuring device and method for an ammonia-hydrogen fuel engine includes the following steps:

[0042] S1: Connection of measuring device: Connect the high-efficiency filter 2 to the air heater 3, connect the heating mixing chamber 4 to the engine 1, the air heater 3, and the dilution channel 5 respectively, connect the critical venturi tube 10 to the dilution channel 5 and the fan 11 respectively, place the first sampler 81 at the outlet end of the air heater 3, place the sensor 7 and the second sampler 82 in the dilution channel 5, and the distance between the sensor 7 and the second sampler 82 and the inlet end of the dilution channel 5 is 5 times the diameter of the dilution channel 5. Finally, connect the first sampler 81 and the second sampler 82 to the analyzer 9, and connect the analyzer 9 and the sensor 7 to the computer 6.

[0043] S2: Preparation before measurement: Turn on the fan 11. The fan 11, as a power source, draws the filtered air through the high-efficiency filter 2 and the air heater 3, as well as the exhaust gas from the engine 1, into the heating and mixing chamber 4 for mixing. The mixed gas flows stably and continuously in the dilution channel 5. When the mixed gas flows through the throat of the critical venturi tube 10, the flow velocity of the mixed gas reaches the local speed of sound, thereby obtaining the critical flow rate V of the critical venturi tube 10.

[0044] S3: Start measuring and acquiring parameters: Obtain the pump pressure P of fan 11. B Total cycle power of engine 1 (W) cycle The temperature T inside the dilution channel 5 is collected using sensor 7. P Pressure P1 and absolute humidity H are measured. The filtered air at the outlet of air heater 3 is sampled using the first sampler 81, and the water vapor concentration c of the filtered air is obtained by the analyzer 9. H2O,dil Concentration of pollutants C in filtered air d The second sampler 82 is used to collect samples of the mixed gas in the dilution channel 5, and the analyzer 9 analyzes the samples to obtain the water vapor concentration c of the mixed gas. H2O,exh The concentration of pollutants in the mixed gas C e The pollutant density ρ of the mixed gas i ;

[0045] S4: Calculate the work-based emission factor of pollutants: First, calculate the dilution ratio DF of the mixed gas in dilution channel 5 to the filtered gas after passing through HEPA filter 2 and air heater 3, and then use the dilution ratio DF to calculate the concentration C of the mixed gas in dilution channel 5. e Corrections are made to prevent pollutants in the filtered air from affecting the measurement of pollutants in the exhaust of engine 1, thereby obtaining the corrected pollutant concentration C. i Then calculate the volume V of the mixed gas flowing through dilution channel 5 every 1 second. mix Humidity correction factor k for NH3 emissions H And based on the obtained C i V mix K H Calculate the mass m of pollutants in the exhaust gas at the i-th second within dilution channel 5. i Finally, for m i By performing approximate integration, the power-based emission factor M of pollutants in the exhaust of engine 1 is obtained. cycle This is used to determine the ammonia emissions of the ammonia-hydrogen fuel cell engine;

[0046] Calculate the dilution ratio DF:

[0047]

[0048] The obtained dilution ratio DF was used to determine the pollutant concentration C in dilution channel 5. e Make corrections and obtain the corrected pollutant concentration C. i :

[0049]

[0050] Calculate the volume V of the mixed gas flowing through dilution channel 5 every 1 second. mix :

[0051]

[0052] Calculate the humidity correction factor k for NH3 emissions H :

[0053]

[0054] Based on the calculated C i V mix K H Calculate the mass m of pollutants in the exhaust gas at second i. i :

[0055] m i =V mix ×C i ×ρ i ×k H

[0056] The mass m of the pollutant per second during the experiment i By performing an approximate integral, the power-based emission factor M is obtained. cycle :

[0057]

[0058] In the formula c H2O,dil C d The concentrations of water vapor and pollutants at the outlet of air heater 3 are c, respectively. H2O,exh C e ρ i These represent the water vapor concentration, pollutant concentration, and pollutant density within dilution channel 5, respectively, T P P1, H, and V represent the temperature, mixed gas pressure, and absolute humidity measured by sensor 7 within dilution channel 5, respectively. V is the critical flow rate of the critical venturi tube 10. B V is the pump pressure of fan 11, DF is the dilution ratio of the mixed gas in dilution channel 5 to the filtered gas after passing through high-efficiency filter 2 and air heater 3, and V is the concentration of the mixed gas in the dilution channel 5. mix To dilute the volume of gas flowing through channel 5 every 1 second, m i Let W be the mass of pollutants in the exhaust of engine 1 at the i-th second. cycleM is the total work done in a cycle of the engine. cycle The power-based emission factor is the pollutant emission factor in the exhaust of engine 1.

[0059] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A device and method for measuring ammonia emissions from an ammonia-hydrogen fuel engine, characterized in that: Includes engine (1), air filter, mixing unit and data acquisition unit; The air filtration device includes a high-efficiency filter (2), which is connected to an air heater (3). The air heater (3) is equipped with a device for removing NO from the air. x catalyst; The mixing device includes a heated mixing chamber (4), which is connected to the engine (1), the air heater (3) and the dilution channel (5) respectively. The dilution channel (5) is connected to a critical venturi tube (10), which is connected to a fan (11). The data acquisition device includes a sensor (7), a first sampler (81), and a second sampler (82). The sensor (7) includes a temperature sensor, a pressure sensor, and a humidity sensor. The sensor (7) and the second sampler (82) are both located in the dilution channel (5). The first sampler (81) is located at the outlet of the air heater (3). The first sampler (81) and the second sampler (82) are both connected to an analyzer (9). The analyzer (9) and the sensor (7) are both connected to a computer (6).

2. The ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to claim 1, characterized in that: The catalyst is a transition metal silicon-oxygen tetrahedron.

3. The ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to claim 1, characterized in that: The air heater (3) and the heating mixing chamber (4) both use resistance wire or burner as heating sources.

4. The ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to claim 1, characterized in that: The temperature inside the air heater (3) is 120°C.

5. The ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to claim 1, characterized in that: The temperature inside the heating mixing chamber (4) is not lower than 130°C.

6. The ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to claim 1, characterized in that: The dilution channel (5) adopts a short dilution channel design.

7. The ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to claim 1, characterized in that: The distance between the sensor (7), the first sampler (81), and the second sampler (82) and the inlet end of the dilution channel (5) is equal to 5 times the diameter of the dilution channel (5).

8. A method for measuring ammonia emissions using the ammonia emission measuring device and method for an ammonia-hydrogen fuel engine according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Connection of measuring device: Connect the high efficiency filter (2) to the air heater (3), connect the heating mixing chamber (4) to the engine (1), the air heater (3), and the dilution channel (5) respectively, connect the critical venturi tube (10) to the dilution channel (5) and the fan (11) respectively, place the first sampler (81) at the outlet end of the air heater (3), place the sensor (7) and the second sampler (82) in the dilution channel (5), and the distance between the sensor (7) and the second sampler (82) and the inlet end of the dilution channel (5) is 5 times the diameter of the dilution channel (5). Finally, connect the first sampler (81) and the second sampler (82) to the analyzer (9), and connect the analyzer (9) and the sensor (7) to the computer (6). S2: Preparation before measurement: Turn on the fan (11). The fan (11) acts as a power source to draw the filtered air through the high-efficiency filter (2) and air heater (3) and the exhaust gas from the engine (1) into the heating mixing chamber (4) for mixing. The mixed gas flows stably and continuously in the dilution channel (5). When the mixed gas flows through the throat of the critical venturi tube (10), the flow velocity of the mixed gas reaches the local speed of sound, thereby obtaining the critical flow rate V of the critical venturi tube (10). S3: Start measuring and acquiring parameters: acquire the pump pressure P of the fan (11). B Total cyclic power W of engine (1) cycle The temperature T in the dilution channel (5) is collected using sensor (7). P Pressure P1 and absolute humidity H are measured. The filtered air at the outlet of the air heater (3) is sampled using the first sampler (81), and the water vapor concentration c of the filtered air is obtained by the analyzer (9). H2O,dil Filtering air pollutant concentration C d The mixed gas in the dilution channel (5) is sampled using the second sampler (82), and the water vapor concentration c of the mixed gas is obtained by the analyzer (9) through analysis of the sample. H2O,exh The concentration of pollutants in the mixed gas C e The pollutant density ρ of the mixed gas i ; S4: Calculate the work-based emission factor of pollutants: First, calculate the dilution ratio DF of the mixed gas in the dilution channel (5) to the filtered gas after passing through the high-efficiency filter (2) and air heater (3), and use the dilution ratio DF to calculate the concentration C of the mixed gas in the dilution channel (5). e Corrections were made to avoid the pollutants contained in the filtered air affecting the measurement of pollutants in the engine (1) exhaust, thereby obtaining the corrected pollutant concentration C. i Then calculate the volume V of the mixed gas flowing through the dilution channel (5) every 1 second. mix Humidity correction factor k for NH3 emissions H And based on the obtained C i V mix K H Calculate the mass m of pollutants in the exhaust gas at the i-th second within the dilution channel (5). i Finally, for m i By performing approximate integration, the power-based emission factor M of pollutants in the exhaust of engine (1) is obtained. cycle This is used to determine the ammonia emissions of the ammonia-hydrogen fuel cell engine; Calculate the dilution ratio DF: The concentration of pollutants C in the dilution channel (5) was determined using the obtained dilution ratio DF. e Make corrections and obtain the corrected pollutant concentration C. i : Calculate the volume V of the mixed gas flowing through the dilution channel (5) every 1 second. mix : Calculate the humidity correction factor k for NH3 emissions H : Based on the calculated C i V mix K H Calculate the mass m of pollutants in the exhaust gas at the i-th second. i : m i =V mix ×C i ×ρ i ×k H The mass m of the pollutant per second during the experiment i By performing an approximate integral, the power-based emission factor M is obtained. cycle : In the formula c H2O,dil C d The water vapor concentration and pollutant concentration at the outlet of the air heater (3) are respectively c H2O,exh C e ρ i The concentrations of water vapor, pollutants, and pollutants in the dilution channel (5) are respectively T. P P1 and H are the temperature, mixed gas pressure and absolute humidity measured by the sensor (7) in the dilution channel (5), respectively; V is the critical flow rate of the critical venturi tube (10); P B V is the pump pressure of the blower (11), DF is the dilution ratio of the mixed gas in the dilution channel (5) to the filtered gas after passing through the high-efficiency filter (2) and the air heater (3), and V is the dilution ratio of the mixed gas in the dilution channel (5) to the filtered gas after passing through the high-efficiency filter (2) and the air heater (3). mix The volume of gas flowing through the dilution channel (5) per second is m. i W represents the mass of pollutants in the exhaust gas of engine (1) at the i-th second. cycle M is the total work done in a cycle of the engine. cycle The power-based emission factor of pollutants in the exhaust of engine (1).

Images