Oxygen concentration measuring device suitable for marine two-stroke electric control low-speed diesel engine

Abstract

An oxygen concentration measuring device suitable for a marine two-stroke electric control low-speed diesel engine comprises an oxygen concentration sensor, a pressure sensor, a junction box processing unit, an air filter, a ball valve, an adaptive block and a steel pipe. The steel pipe is provided with an inlet and an outlet, the air filter is arranged behind the inlet and used for filtering waste gas, the ball valve controls on-off of a gas passage, the adaptive block is mounted behind the ball valve and provided with a redundant interface used for mounting a sensor, and the junction box processing unit is responsible for signal transmission and processing. According to the device, the NOx emission level is indirectly calculated by monitoring the oxygen concentration change in waste gas in real time and combining pressure data, and the requirement of the IMO Tier III emission standard is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of emission control of marine power systems, and specifically relates to an oxygen concentration measuring device, which indirectly estimates nitrogen oxides (NO X ) concentration, thus meeting the emission standards of the International Maritime Organization (IMO) Background Art

[0002] Diesel engines produce nitrogen oxides (NO X ), whose emissions are strictly limited by the International Maritime Organization (IMO) Tier III emission standards. When navigating specific sea areas, diesel engines must comply with NOx emission limits or they will be unable to pass. Therefore, real-time monitoring of NOx concentrations and adjusting combustion conditions have become critical requirements for diesel engine operation.

[0003] However, direct measurement of NO X Concentration usually requires complex and expensive equipment with high maintenance costs. In contrast, indirectly estimating NOx concentration by monitoring changes in oxygen concentration is a more economical and efficient method. There is a certain correlation between oxygen concentration and NOx concentration, especially in the diesel engine combustion process, where changes in oxygen concentration can reflect combustion efficiency and NOx concentration. X The generation situation.

[0004] At present, the application of existing oxygen concentration measurement devices in marine diesel engines still has some shortcomings, such as complex structure, inconvenient operation or difficulty in adapting to harsh marine environments.

[0005] Therefore, there is an urgent need for a device with a simple structure, high reliability and the ability to monitor oxygen concentration in real time to meet the needs of diesel engine emission control. Summary of the Invention

[0006] The purpose of the present invention is to provide an oxygen concentration measuring device suitable for a marine two-stroke electronically controlled low-speed diesel engine, which can detect the oxygen concentration content inside the diesel engine in real time and is simple to operate and easy to use.

[0007] The technical solution of the present invention:

[0008] An oxygen concentration measuring device suitable for a marine two-stroke electronically controlled low-speed diesel engine is characterized by comprising:

[0009] Oxygen concentration sensor, used to detect the oxygen content in exhaust gas;

[0010] Pressure sensor, used to monitor the pressure of exhaust gas;

[0011] a junction box processing unit, electrically connected to the oxygen concentration sensor and the pressure sensor, respectively, for receiving and processing sensor signals;

[0012] Air filter, used to filter particulate matter and impurities in exhaust gas;

[0013] Ball valve, used to control the on and off of the gas passage;

[0014] An adapter block having grooves for the oxygen concentration sensor and the pressure sensor;

[0015] Steel pipe, with an inlet (A) and an outlet (B);

[0016] Wherein, the air filter is arranged behind the inlet (A), the ball valve is arranged behind the air filter and before the adapter block, and the adapter block is arranged behind the ball valve and before the outlet (B).

[0017] Furthermore, the adapter block is provided with a redundant interface, including at least two sensor installation positions for installing spare sensors.

[0018] Furthermore, the air filter is detachable, which facilitates regular cleaning or replacement of the filter element.

[0019] Furthermore, the junction box processing unit transmits the processed sensor signal to the diesel engine control system for real-time monitoring and adjustment of the combustion state.

[0020] Furthermore, the inlet (A) is connected to the exhaust system of the diesel engine for extracting exhaust gas after combustion; and the outlet (B) is connected to the exhaust pipe or the atmosphere.

[0021] Except for the oxygen concentration sensor, pressure sensor and junction box processing unit, the remaining parts are connected by the steel pipe.

[0022] A marine two-stroke electronically controlled low-speed diesel engine is characterized in that it is equipped with the above-mentioned oxygen concentration measuring device for real-time monitoring of oxygen concentration and optimization of the combustion process.

[0023] Furthermore, when the oxygen concentration is lower than a set threshold, the control system automatically adjusts the fuel injection parameters or the exhaust gas recirculation system to reduce NOx emissions.

[0024] The working state of the present invention is as follows:

[0025] 1) The inlet is connected to the inside of the diesel engine and is used to lead a small part of the exhaust gas after combustion in the diesel engine to the oxygen concentration measuring device.

[0026] 2) Under normal operation of the diesel engine, the ball valve connects the inlet to any adapter block (the other one is a redundant design). After the exhaust gas passes through the air filter to remove impurities, it passes through the ball valve to the adapter block to measure the oxygen concentration and pressure. The results are then transmitted to the control system through the junction box processing unit.

[0027] 3) When the oxygen concentration in the diesel engine is too low (corresponding to the NOx concentration being too high), the control system will issue an alarm and adjust the combustion state of the diesel engine.

[0028] The technical effects of the present invention are as follows:

[0029] 1. By working in conjunction with an oxygen concentration sensor and a pressure sensor, the oxygen concentration in the exhaust gas is monitored in real time, and NOx concentration is indirectly calculated using a combustion model. This method avoids the high cost of direct NOx measurement while ensuring data reliability, fully meeting the monitoring requirements of the IMO Tier III emission standard.

[0030] 2. It is directly connected to the diesel engine exhaust system through a steel pipe. The exhaust gas sampling response time is short, which can quickly reflect changes in the combustion state and provide real-time data support for the control system. The adapter block is equipped with two sensor mounting positions. Combined with the switching function of the ball valve, it can seamlessly switch to the backup channel when the main sensor fails to ensure uninterrupted monitoring. This design significantly improves the reliability of the device in harsh marine environments. The junction box processing unit transmits the processed oxygen concentration and pressure signals to the diesel engine control system to form a closed-loop feedback. When the oxygen concentration is lower than the set threshold (such as 5%), the system automatically triggers an alarm and adjusts the fuel injection parameters or the EGR (exhaust gas recirculation) system to optimize the combustion process and reduce NOx emissions from the source. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a component diagram of an oxygen concentration measuring device. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments, but this should not limit the scope of protection of the present invention.

[0033] The oxygen concentration measuring device of the present invention is mainly used for marine two-stroke electronically controlled low-speed diesel engines. It can indirectly estimate NO by monitoring the changes in oxygen concentration in exhaust gas in real time. X Emission levels to meet the requirements of IMO Tier III emission standards. The device mainly includes the following components (such as Figure 1 shown):

[0034] Oxygen concentration sensor 1: used to detect the oxygen content in the exhaust gas and output an electrical signal.

[0035] Pressure sensor 2: used to monitor the pressure of exhaust gas and ensure a stable measurement environment.

[0036] Junction box processing unit 3: receives signals from oxygen concentration sensor 1 and pressure sensor 2, processes the data and transmits it to the diesel engine control system.

[0037] Air filter 4: Installed after the inlet (A), it is used to filter particles and impurities in the exhaust gas to prevent the sensor from being blocked or damaged.

[0038] Ball valve 5: It is set after the air filter 4 and before the adapter block 6. It is used to control the on-off of the gas passage and can switch the backup measurement channel during maintenance.

[0039] Adapter block 6: used to fix the oxygen concentration sensor 1 and the pressure sensor 2, and is provided with a redundant interface to facilitate replacement or expansion of the sensors.

[0040] Steel pipe 7: connects various components to form a gas flow channel. The inlet (A) is connected to the diesel engine exhaust system, and the outlet (B) can be connected to the exhaust pipe or the atmosphere.

[0041] Adapter block 6 features two sensor mounting locations. If the primary sensor fails, ball valve 5 switches to the backup channel, ensuring measurement continuity. This switching function allows the current channel to be closed and switched to the backup channel during sensor maintenance or calibration without affecting normal engine operation. The removable air filter 4 facilitates regular cleaning and replacement, preventing clogging that could affect measurement accuracy.

[0042] The workflow of this embodiment is as follows:

[0043] Exhaust gas sampling: When the diesel engine is running, the exhaust gas after combustion enters the oxygen concentration measuring device through the inlet (A).

[0044] Filtration treatment: The exhaust gas first passes through the air filter 4 to remove particulate matter and impurities to ensure the measurement accuracy of subsequent sensors.

[0045] Flow control: Ball valve 5 adjusts the exhaust gas flow, and the main measurement channel or the backup channel (redundant design) can be selected.

[0046] Oxygen concentration and pressure measurement: Exhaust gas enters the adapter block 6, and the oxygen concentration sensor 1 and pressure sensor 2 detect the oxygen content and pressure data in real time.

[0047] Signal processing and transmission: The junction box processing unit 3 receives the sensor signal, converts the data and transmits it to the diesel engine control system.

[0048] Emission control: The control system calculates the NOx emission level based on oxygen concentration data. If it exceeds the limit, it adjusts the fuel injection parameters or the EGR (exhaust gas recirculation) system to optimize the combustion process.

[0049] Example: Taking a certain type of marine two-stroke low-speed diesel engine as an example, after installing the oxygen concentration measuring device:

[0050] When the oxygen concentration is lower than the set threshold (such as 5%), the control system determines that NOx emissions may exceed the standard, triggers an alarm and automatically adjusts the combustion parameters.

[0051] In long-term operation, the air filter 4 should be cleaned every 500 hours and the sensor should be calibrated every 2000 hours to ensure measurement stability.

[0052] This embodiment achieves efficient monitoring and control of diesel engine emissions by optimizing the structure and workflow of the oxygen concentration measurement device, meeting IMO Tier III emission requirements. It also has the advantages of simple operation and easy maintenance, and is applicable to various marine diesel engine systems.

Claims

1. An oxygen concentration measuring device suitable for a marine two-stroke electronically controlled low-speed diesel engine, characterized in that: include: an oxygen concentration sensor (1), for detecting the oxygen content in the exhaust gas; a pressure sensor (2) for monitoring the pressure of the exhaust gas; a junction box processing unit (3), electrically connected to the oxygen concentration sensor (1) and the pressure sensor (2), respectively, and configured to receive and process sensor signals; an air filter (4) for filtering particulate matter and impurities in the exhaust gas; A ball valve (5) is used to control the on / off of the gas passage; An adapter block (6) is provided with grooves for the oxygen concentration sensor (1) and the pressure sensor (2); A steel pipe (7) having an inlet (A) and an outlet (B); The air filter (4) is arranged behind the inlet (A), the ball valve (5) is arranged behind the air filter (4) and before the adapter block (6), and the adapter block (6) is arranged behind the ball valve (5) and before the outlet (B).

2. The oxygen concentration measuring device for a marine two-stroke electronically controlled low-speed diesel engine according to claim 1, characterized in that: The adapter block (6) is provided with a redundant interface, including at least two sensor installation positions for installing spare sensors.

3. The oxygen concentration measuring device for a marine two-stroke electronically controlled low-speed diesel engine according to claim 1, characterized in that: The air filter (4) is designed to be detachable, making it easy to clean or replace the filter element regularly.

4. The oxygen concentration measuring device for a marine two-stroke electronically controlled low-speed diesel engine according to claim 1, characterized in that: The junction box processing unit (3) transmits the processed sensor signal to the diesel engine control system for real-time monitoring and adjustment of the combustion state.

5. The oxygen concentration measuring device for a marine two-stroke electronically controlled low-speed diesel engine according to claim 1, characterized in that: The inlet (A) is connected to the exhaust system of the diesel engine for extracting the exhaust gas after combustion; the outlet (B) is connected to the exhaust pipe or the atmosphere.

6. A marine two-stroke electronically controlled low-speed diesel engine, characterized in that: An oxygen concentration measuring device as described in any one of claims 1 to 5 is installed to monitor the oxygen concentration in real time and optimize the combustion process.

7. The marine two-stroke electronically controlled low-speed diesel engine according to claim 6, characterized in that: When the oxygen concentration is lower than the set threshold, the control system automatically adjusts the fuel injection parameters or the exhaust gas recirculation system to reduce NOx emissions.

Images