Methanol fuel engine waste gas monitoring system

Abstract

The invention discloses a methanol fuel engine waste gas monitoring system, and belongs to the technical field of environment monitoring and control. The system comprises a gas pretreatment module, a measurement and analysis module, a calibration control module and a data management module, the gas pretreatment module is used for collecting and conveying sample gas and adjusting the gas quantity; the measurement and analysis module is used for detecting the concentration of formaldehyde and methanol for the sample gas treated by the gas pretreatment module by adopting two optical methods of ultraviolet difference and non-dispersive infrared; the calibration control module realizes zero setting and calibration functions of the gas pretreatment module and the measurement and analysis module under the control of the calibration function of the upper computer; and the data management module realizes data acquisition, analysis, display, storage and control functions in the gas pretreatment module, the measurement analysis module and the calibration control module through upper computer software. The temperature, flow and pressure of waste gas are adjusted through the gas pretreatment module, and the concentration of methanol and formaldehyde in the waste gas is automatically measured on line through the measurement and analysis module.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental monitoring and control, and particularly to an exhaust gas monitoring system for a methanol fuel engine. Background Art

[0002] As a clean fuel, the technology of methanol fuel engines has received great attention and achieved a certain degree of development and application. When burning methanol, due to factors such as combustion temperature, load change, and engine speed, unburned methanol and formaldehyde will be generated in the combustion exhaust gas.

[0003] Therefore, from the perspectives of environmental protection and energy efficiency improvement, it is necessary to monitor the exhaust gas components of methanol fuel engines. Currently, the monitoring of engine exhaust gas focuses on the detection of automobile exhaust (CO, CO2, HC, NOx, O2, etc.) using traditional fossil fuels, and there are currently no relevant professional exhaust gas detection devices and methods for methanol engine exhaust gas monitoring. Summary of the Invention

[0004] In view of this, the present invention provides an exhaust gas monitoring system for a methanol fuel engine, which directly inserts a high-temperature sampling probe into the pipeline to collect the high-temperature exhaust gas after engine combustion, and adjusts the temperature, flow rate, and pressure of the exhaust gas through gas pretreatment, and finally uses an optical analysis method to realize the on-line and automatic measurement of the concentrations of methanol and formaldehyde in the exhaust gas.

[0005] An exhaust gas monitoring system for a methanol fuel engine includes a gas pretreatment module, a measurement and analysis module, a calibration control module, and a data management module;

[0006] The gas pretreatment module realizes the collection, transportation, and gas volume adjustment of the sample gas to meet the requirements of the measurement and analysis module for analysis and detection;

[0007] The measurement and analysis module uses two optical methods, ultraviolet difference and non-dispersive infrared, to respectively detect the concentrations of formaldehyde and methanol in the sample gas processed by the gas pretreatment module;

[0008] The calibration control module realizes the zero adjustment and calibration functions of the gas pretreatment module and the measurement and analysis module under the control of the calibration function of the upper computer;

[0009] The data management module realizes the functions of data collection, analysis, display, storage, and control in the gas pretreatment module, the measurement and analysis module, and the calibration control module through upper computer software.

[0010] Further, the gas pretreatment module includes a sampling probe, an electric tracing pipeline, a heating box, a high-temperature gas chamber, a condenser, and a suction pump;

[0011] The sampling probe is connected to the inlet of the high-temperature gas chamber inside the heating box through an electrically traced pipeline. The outlet of the high-temperature gas chamber is connected to the inlet of the condenser outside the heating box through an electrically traced pipeline, and the outlet of the condenser is connected to the air extraction pump through an electrically traced pipeline.

[0012] Furthermore, the measurement and analysis module includes a formaldehyde analysis unit, a methanol analysis unit, and an optical fiber; the formaldehyde analysis unit is connected to the high-temperature gas chamber through the optical fiber, and the methanol analysis unit is connected between the condenser and the air extraction pump.

[0013] Furthermore, the calibration control module includes a solenoid valve, a pneumatic valve, and a flow meter. The peripheral devices are an air compressor and an air storage tank; the air compressor is connected to the air storage tank. There are two outlets on the air storage tank. The first outlet is connected to the sampling probe through a pipeline, and a solenoid valve is connected to the pipeline. The second outlet is connected to the pipeline between the high-temperature gas chamber and the sampling probe through a pipeline, and a pneumatic valve is installed at the connection. A solenoid valve is connected to the pipeline between the pneumatic valve and the air storage tank; two pipelines are connected in parallel to the pipeline between the pneumatic valve and the high-temperature gas chamber, and solenoid valves are respectively installed on the two pipelines; the flow meter is installed on the pipeline between the methanol analysis unit and the air extraction pump.

[0014] Furthermore, a filter is installed on the electrically traced pipeline between the sampling probe and the pneumatic valve, and a humidity module is installed on the electrically traced pipeline between the high-temperature gas chamber and the condenser.

[0015] Beneficial effects:

[0016] 1. The exhaust gas monitoring system of the present invention is composed of a gas pretreatment module, a measurement and analysis module, a calibration control module, and a data management module. During monitoring, only the high-temperature sampling probe in the gas pretreatment module needs to be installed on the discharge pipeline in a flange manner, and the exhaust gas monitoring device can automatically realize sampling, transmission, analysis, and result display.

[0017] 2. The measurement and analysis system of the present invention uses two optical methods, ultraviolet differential and non-dispersive infrared, to respectively detect the concentrations of formaldehyde and methanol; to ensure the performance of the equipment and facilitate equipment calibration, a calibration control system is integrated, and the system calibration can be manually or automatically realized.

[0018] 3. The exhaust gas monitoring system of the present invention comprehensively adopts an optical detection method as a whole and has the characteristics of high measurement accuracy, good reliability, and convenient maintenance through modular design, and is suitable for the scenario of on-line detection of the exhaust gas components of methanol engines. Description of the drawings

[0019] Figure 1 It is the composition schematic diagram of the exhaust gas monitoring system of the methanol fuel engine of the present invention. Specific implementation manners

[0020] The present invention will be described in detail below in conjunction with the accompanying drawings and by way of examples.

[0021] The present invention provides a waste gas monitoring system for a methanol fuel engine. Functionally, the system is divided into four major parts: a gas pretreatment module, a measurement and analysis module, a calibration and control module, and a data management module.

[0022] As shown in the Figure 1 accompanying drawings, the gas pretreatment module includes a sampling probe, an electrically heated tracing pipeline, a heating box, a high-temperature gas chamber, a condenser, a humidity module, and a suction pump; the sampling probe is connected to the inlet of the high-temperature gas chamber inside the heating box through the electrically heated tracing pipeline, the outlet of the high-temperature gas chamber is connected to the inlet of the condenser outside the heating box through the electrically heated tracing pipeline, the outlet of the condenser is connected to the suction pump through the heated tracing pipeline, and the humidity module is installed on the electrically heated tracing pipeline between the high-temperature gas chamber and the condenser.

[0023] The measurement and analysis module includes a formaldehyde analysis unit, a methanol analysis unit, and an optical fiber; the formaldehyde analysis unit is connected to the high-temperature gas chamber through the optical fiber, and the methanol analysis unit is connected between the condenser and the suction pump.

[0024] The calibration and control module includes solenoid valves F1, F2, F3, F4, a pneumatic valve, and a flow meter. The peripheral devices are an air compressor and a gas storage tank; the air compressor is connected to the gas storage tank. The gas storage tank has two outlets. The first outlet is connected to the sampling probe through a pipeline, and the solenoid valve F4 is connected to the pipeline. The second outlet is connected to the pipeline between the high-temperature gas chamber and the sampling probe through a pipeline. A pneumatic valve is installed at the connection point. The solenoid valve F3 is connected to the pipeline between the pneumatic valve and the gas storage tank, and a filter is connected to the pipeline between the pneumatic valve and the sampling probe; two pipelines are connected in parallel to the pipeline between the pneumatic valve and the high-temperature gas chamber, and the solenoid valves F1 and F2 are respectively installed on the two pipelines. The solenoid valve F1 is used for zero adjustment, and the solenoid valve F2 is used for calibration; the flow meter is installed on the pipeline between the methanol analysis unit and the suction pump.

[0025] The waste gas monitoring system for a methanol fuel engine of the present invention has three working modes: measurement, purging, and calibration. The specific working methods are as follows:

[0026] Measurement mode: When the system is in a normal measurement state, the waste gas is sampled through the sampling probe and transmitted to the heating box through the electrically heated tracing pipeline. In the heating box, the sampled gas enters the high-temperature gas chamber through the filter and the pneumatic valve. The formaldehyde analysis unit outside the heating box detects the sampled gas in the high-temperature gas chamber through the optical fiber, and the formaldehyde concentration is measured here by the high-temperature ultraviolet differential method; after passing through the high-temperature gas chamber, the sampled gas passes through the humidity module and the condenser, is quickly condensed, dried, and enters the methanol analysis unit, where the methanol concentration is detected by the non-dispersive infrared method. After the detection is completed, the sampled gas is evacuated through the flow meter and the sampling pump.

[0027] Purge Mode: In the purge mode, the sampling probe and the analyzer are purged separately with clean compressed air. One path of clean air passes through solenoid valve F4 and reaches the sampling probe through the electrically traced pipeline to achieve purging; the other path of clean air passes through solenoid valve F3, pneumatic valve and purges and cleans the pipelines and components such as the high-temperature gas chamber, humidity module, condenser, methanol analysis unit, flow meter, etc. in sequence.

[0028] Calibration Mode: The system supports automatic or manual zero adjustment and calibration functions. The system externally connects a standard gas cylinder (zero gas or span gas), which enters the formaldehyde analysis unit and methanol analysis unit in sequence through the control of solenoid valve F1 (zero gas) or solenoid valve F2 (span gas), and the system calibration can be achieved in cooperation with the calibration function of the upper computer.

[0029] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A methanol fuel engine exhaust gas monitoring system, characterized in that: It includes gas pre-processing module, measurement and analysis module, calibration control module and data management module; The gas pretreatment module realizes the collection, transportation and gas volume regulation of the sample gas to meet the requirements of the analysis and detection of the measurement and analysis module; The measurement and analysis module uses ultraviolet differential and non-dispersive infrared optical methods to detect the concentrations of formaldehyde and methanol respectively on the sample gas processed by the gas pre-processing module; The calibration control module realizes the zeroing and calibration functions of the gas pretreatment module and the measurement and analysis module under the control of the calibration function of the host computer; The data management module realizes the data collection, analysis, display, storage and control functions in the gas pretreatment module, the measurement and analysis module and the calibration control module through the host computer software.

2. The methanol fuel engine exhaust monitoring system according to claim 1, characterized in that: The gas pretreatment module includes a sampling probe, an electric heating pipeline, a heating box, a high-temperature gas chamber, a condenser and a vacuum pump; The sampling probe is connected to the inlet of the high-temperature gas chamber inside the heating box through an electric heating pipeline, the outlet of the high-temperature gas chamber is connected to the inlet of the condenser outside the heating box through the electric heating pipeline, and the outlet of the condenser is connected to the vacuum pump through the electric heating pipeline.

3. The methanol fuel engine exhaust monitoring system as claimed in claim 2, characterized in that: The measurement and analysis module includes a formaldehyde analysis unit, a methanol analysis unit and an optical fiber; the formaldehyde analysis unit is connected to the high-temperature gas chamber through the optical fiber, and the methanol analysis unit is connected between the condenser and the vacuum pump.

4. The methanol fuel engine exhaust monitoring system according to claim 1, characterized in that: The calibration control module includes a solenoid valve, a pneumatic valve and a flow meter, and the peripheral equipment is an air compressor and a gas tank; the air compressor is connected to the gas tank, and the gas tank has two outlets, the first outlet is connected to the sampling probe through a pipeline, and the pipeline is connected to a solenoid valve, and the second outlet is connected to the pipeline between the high-temperature gas chamber and the sampling probe through a pipeline, and a pneumatic valve is installed at the connection, and the solenoid valve is connected to the pipeline between the pneumatic valve and the gas tank; two pipelines are connected in parallel on the pipeline between the pneumatic valve and the high-temperature gas chamber, and solenoid valves are installed on the two pipelines respectively; the flow meter is installed on the pipeline between the methanol analysis unit and the vacuum pump.

5. The methanol fuel engine exhaust monitoring system according to claim 3 or 4, characterized in that: A filter is installed on the electric heating pipeline between the sampling probe and the pneumatic valve, and a humidity module is installed on the electric heating pipeline between the high-temperature gas chamber and the condenser.

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