A method for measuring real ship emission factors based on load-ship speed conversion relationship

Abstract

The application discloses a kind of based on load-ship speed conversion relationship real ship emission factor measurement method, can realize obtain reality difficultly according to ship work load obtains the emission factor of different ship type each regulation operating point, and then constructs the emission factor library of this ship under each operating condition, mainly includes the following steps: the relationship between regulation operating point and speed is constructed by formula, and four steady operating conditions in ship engine test cycle are converted into speed;Real ship test is carried out to ship using self-built emission test system, and gaseous pollutants and particulate matters in the process of ship operation are collected;Real ship test is carried out at the corresponding speed after the conversion of four regulation operating points, and the ship emission factor based on different speed under real ship test is obtained after data is recorded, analyzed and calculated simultaneously;A relational expression is constructed, and for the ship type that ship work load is not easy to obtain, the ship emission factor under different load can be obtained by controlling speed.

Description

Technical Field

[0001] This invention relates to the field of ship emission testing technology, and specifically to a method for measuring ship emission factors based on the load-speed conversion relationship. Background Technology

[0002] my country is a major shipping nation, boasting the world's largest number of ports and the highest port capacity. The impact of ship emissions on regional atmospheric environments and ecosystems is increasingly prominent. Due to the diverse types of ships and their high emission concentrations, ship pollution within port areas is severe, directly affecting the health of port workers and residents in surrounding areas. Currently, ship emission inventories are commonly used to quantify and analyze ship air pollutant emissions and formulate relevant emission control policies. However, due to limitations in research conditions, my country's ship inventory construction methods are not perfect. A significant aspect is the lack of localized emission factors. Most domestic studies currently adopt emission factors from the US Environmental Protection Agency guidelines. However, my country's ship engine technology, marine fuel quality, and ship pollution control technologies are not entirely the same as those in the US. Directly applying emission factors from foreign guidelines or other literature leads to significant uncertainty in inventory calculation results. Existing ship emission testing methods mainly fall into three categories: plume telemetry, bench testing, and ship-to-ship testing. Compared to telemetry and bench testing, ship-to-ship testing can accurately reflect the emissions of ships during actual navigation, eliminating errors that may be caused by environmental and operational factors in telemetry and bench testing.

[0003] Currently, many research institutions have conducted extensive research on ship emission factor testing. Chinese invention patent application number 202010595327.3 relates to a ship emission testing method based on power emission factor; Chinese invention patent application number 202111424179.X relates to a method for estimating ship main engine nitrogen oxide emissions based on dynamic emission factor; and Chinese invention patent application number 202310801791.7 relates to a localized emission factor testing method for operating ships. However, these methods fail to obtain ship emission factors based on steady-state operating points under different loads by controlling speed, and they present significant operational difficulties for ship types where it is not easy to obtain emission factors under ship operating loads. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a method for measuring ship emission factors based on the load-speed conversion relationship. This method can obtain emission factors for different ship types at various regulatory operating conditions, which are difficult to obtain based on ship workload in reality, and thus construct an emission factor database for each operating condition of the ship. The purpose of this invention is achieved through the following technical solution:

[0005] The relationship between the regulatory operating point and the speed is constructed by formula, and the four steady-state operating conditions in the test cycle of the ship engine are converted into speed.

[0006] The ship was tested using a self-built emission testing system to collect gaseous pollutants and particulate matter during the ship's operation.

[0007] After converting the four regulatory operating conditions, actual ship tests were conducted at the corresponding speeds. The data were recorded, analyzed, and calculated to obtain the ship emission factors based on different speeds under the actual ship test.

[0008] By constructing a relational formula, for ship types where it is difficult to obtain the ship's working load, the ship's emission factor under different loads can be obtained by controlling the speed.

[0009] Furthermore, the specific description of constructing the relationship between the regulatory operating point and the speed using a formula is as follows:

[0010] The relationship between engine load and main engine speed is as follows:

[0011]

[0012] Where RPM is the main engine speed, RPM ( R () represents the rated speed, and ENL represents the engine load at the steady-state operating point;

[0013] The relationship between ship speed and main engine speed is as follows:

[0014]

[0015] Where V is the ship's speed in km / h; P is the propeller pitch, which refers to the distance the propeller propels per revolution in a solid environment; RPM is the engine speed; S R The slip ratio refers to the ratio of the theoretical propeller speed np to the actual propeller speed V. P The ratio of the difference to the theoretical propeller speed:

[0016]

[0017] Where n is the propeller rotational speed; P is the propeller pitch; V P V is the propeller's forward velocity, and V is the ship's speed.

[0018] The relationship between engine speed and engine load at the regulatory operating point is as follows:

[0019]

[0020]

[0021] Furthermore, the four steady-state operating conditions are as follows: referring to the international mainstream ISO-8178 marine engine test cycle, steady-state operating condition tests with engine loads of 25%, 50%, 75%, and 100% are added, with corresponding weighting factors of 0.2, 0.5, 0.15, and 0.15, respectively. Each test condition lasts for at least 20 minutes to ensure that the engine enters a stable state.

[0022] Furthermore, the conversion of the four steady-state operating conditions in the ship engine test cycle into speed specifically involves substituting the steady-state operating points with engine loads of 25%, 50%, 75%, and 100% into the corresponding formulas to convert them into speed.

[0023] Furthermore, the self-built emission testing system is based on portable exhaust emission equipment and also includes: Dekati jet diluter (Dekati Diluter DI-1000, Finland), HY-100WS high-load particulate matter collector (Qingdao Hengyuan Instrument Co., Ltd., China), SUMMA tank, AC-GC MS2000 atmospheric volatile organic compound monitoring system (Hexin, China), and SEMTECH-DS vehicle exhaust gas analysis system (SENSORS, USA).

[0024] Furthermore, the gaseous pollutants and particulate matter collected during ship operation include: CO2, CO, NO, NO2, THC, PM, and SO2.

[0025] Furthermore, the ship operating parameters include: ship main engine power, speed, rotational speed, fuel consumption, exhaust flow rate, and exhaust temperature.

[0026] Furthermore, the aforementioned method for calculating ship emission factors, based on fuel emission factors, can eliminate the influence of different engine power levels.

[0027]

[0028] EF i (Fuel) is the fuel consumption-based emission factor for pollutant i, in g / kg·fuel; x f Carbon content per unit mass of fuel, g·C / kg·fuel; C i The mass concentration of carbon in pollutant i in the exhaust gas ( i = CO2, CO, HC, OC + EC).

[0029] The formulas for converting fuel-based emission factors into power-based and mileage-based emission factors are as follows:

[0030]

[0031]

[0032] Where FC is the fuel consumption rate (kg / h), P is the engine power (kW), and v is the speed (km / h).

[0033] Furthermore, the aforementioned construction of the relationship, obtaining the ship emission factor under different loads by controlling the speed, specifically involves: solving for the corresponding ship speed through the relationship between engine load and ship speed, and then substituting this ship speed into the emission factor calculation formula based on mileage to obtain the emission factor for ship types where the ship's working load is not easily obtained. Attached Figure Description

[0034] Figure 1 This is a flowchart of a method for measuring ship emission factors based on load-speed conversion relationship as described in this invention.

[0035] Figure 2 This is a schematic diagram of PEMS connection in an embodiment of the present invention;

[0036] Figure 3 The diagram shows the SEMTECH-DS exhaust gas analysis system in the embodiment of the present invention (left: SEMTECH-DS exhaust gas analyzer, right: SEMTECH-EFM3 exhaust gas flow meter).

[0037] Figure 4 This is a diagram of ship emission factors under different operating conditions in the embodiments of the present invention;

[0038] Figure 5 This is a diagram of ship emission factors under different loads in the embodiments of the present invention;

[0039] Figure 6 This refers to the ship emission factor based on speed in the embodiments of the present invention. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the specific embodiments of the present invention are not limited thereto.

[0041] Example:

[0042] A method for measuring ship emission factors based on load-speed conversion relationship, such as Figure 1As shown, following the international mainstream ISO-8178 marine engine test cycle, four steady-state operating points are added to the cruise condition. The relationship between the regulatory operating points and the speed is constructed through formulas, and the relationship is converted into speed. The actual ship test is repeated using a self-built emission test system, and the data is recorded twice. The ship emission factor based on different speeds is calculated. Through the relationship, the ship emission factor under different loads can be obtained by controlling the speed.

[0043] Test route: from Bohai Bay into the Yangtze River hinterland, and then back to Bohai Bay from the Yangtze River hinterland. Each working condition will be tested at least twice to ensure the reliability of the data.

[0044] Test vessel: The test subject is a large bulk carrier built in 2012 with a rated load of 50,000 tons, equipped with a 4-stroke low-speed diesel engine with a rated speed of 114 rpm and a rated power of 6300 kW.

[0045] Table 1 Test vessel parameters

[0046] type parameter name Huaheng type Cargo ship call sign BIAX3 IMO 414118000 (China) Design draft 10.2 m Width 32.3 m Deep 15.4 m Type length 200.1 m years 2012

[0047] Step 1: Construct the relationship between the regulatory operating point and the engine speed using formulas, and establish the relationship between the engine speed, main engine speed, and engine load:

[0048] The relationship between engine load and main engine speed is as follows:

[0049] (1)

[0050] Where RPM is the main engine speed, RPM ( R ) represents the rated speed, and ENL represents the engine load at the steady-state operating point.

[0051] The relationship between ship speed and main engine speed is as follows:

[0052] (2)

[0053] Where V is the ship's speed in km / h; P is the propeller pitch, which refers to the distance the propeller propels per revolution in a solid environment; RPM is the engine speed; S R The slip ratio refers to the ratio of the theoretical propeller speed np to the actual propeller speed V. P The ratio of the difference to the theoretical propeller speed:

[0054] (3)

[0055] The relationship between engine speed and engine load at the regulatory operating point is as follows:

[0056] (4)

[0057] (5)

[0058] The selection of test conditions and the setting of steady-state operating points. Test conditions encompass the typical navigation processes of a ship during actual navigation, including four main operating conditions: departure, cruising, maneuvering, and entering port. In the departure and entering port conditions, the ship's power fluctuates significantly and is assisted by two pushers, lasting 1-2 hours, with the ship's speed generally less than 4 knots (kN). Cruising refers to the entire voyage in the Yellow Sea, with a speed of 12 knots. Maneuvering refers to the ship's navigation in the Yangtze River section.

[0059] In the cruise test, the test was conducted according to the E3 test cycle, referencing the international mainstream ISO-8178 marine engine test cycle. The test added steady-state test points of 25%, 50%, 75%, and 90%, with each test lasting at least 20 minutes to ensure that the engine enters a stable state.

[0060] Table 2 ISO-8178 Test Cycle

[0061]

[0062] From equations (1), (2), (3), and (4), we can obtain the relationship between speed, engine speed, and engine load under different loads during this voyage:

[0063] Table 3 Engine parameters under ISO-8178 test cycle

[0064] Engine load 25% 50% 75% 90% Speed ​​(kn) 8.8 11.2 12.7 13.6 Power (kW) 1708~1714 3415~3470 5123~5136 6147~6162 Rotational speed (r / min) 70.6 88.9 101.8 108.1

[0065] Step 2: Based on portable mobile source exhaust gas emission equipment, an emission measurement system was independently built to achieve real-time acquisition of emission concentrations and rates of different types of ship pollutants under actual operating conditions. For ship main engines, large ships are generally equipped with inspection ports on their exhaust ducts, allowing direct extraction of ship exhaust gas for testing. Smaller vessels, such as fishing boats and tugboats, generally do not have inspection ports, and full-flow or partial-flow sampling methods can be used to introduce ship exhaust gas into the testing channel for analysis. The equipment connection process is as follows: Figure 2 As shown.

[0066] To more realistically simulate the cooling, dilution, and condensation process of exhaust gas in a real environment, the exhaust gas needs to be diluted in the dilution channel before entering the particulate matter collection and analysis equipment. The dilution system is based on Dekati's jet diluter (Dekati Diluter DI-1000, Finland), with a dilution ratio of (8:1~1000:1), which is selected according to the exhaust gas concentration of the emission source. Ship exhaust gas concentration is high, so a higher dilution ratio is required.

[0067] Design two HY-100WS high-load particulate matter samplers to sample PM2.5. 2.5 Samples were collected from a Teflon filter membrane (90 mm in diameter) and a quartz filter membrane (90 mm in diameter).

[0068] The emission analysis of gaseous pollutants in this study was mainly based on SEMTECH series equipment (SENSORS, USA) and its supporting components. The SEMTECH vehicle exhaust gas analysis system is a highly integrated and high-precision testing device, including the SEMTECH-DS vehicle exhaust gas analyzer, SEMTECH-EFM vehicle exhaust gas flow meter, temperature and humidity sensors, and Global Positioning System (GPS) temperature and humidity sensors, among other modules. Figure 3 As shown.

[0069] The third step involved conducting a two-week actual voyage test on the test subject—a large ocean-going vessel—using a self-built emission testing system. The data collected mainly included gaseous pollutants (CO2, CO, NO, NO2, THC, SO2) and particulate matter. Through actual ship testing, the impact of the ship's operating conditions, speed, and power on the ship's emission factors was studied and analyzed. During the test, the ship's operating parameters and emission data were recorded simultaneously.

[0070] The ship's operating parameters were recorded at various operating conditions, including main engine power, speed, RPM, fuel consumption, exhaust flow rate, and exhaust temperature. The entire test was conducted during the Yellow Sea navigation phase, and was repeated twice to ensure the reliability of the experimental data.

[0071] Ship emission factor calculation methods, based on fuel emission factors, can eliminate the influence of different engine power levels:

[0072] (6)

[0073] EF i ( Fuel ) represents the fuel consumption-based emission factor of pollutant i, in g / kg·fuel; x f Carbon content per unit mass of fuel, g·C / kg·fuel; C i The mass concentration of carbon in pollutant i in the exhaust gas ( i = CO2, CO, HC, OC + EC).

[0074] Formulas for converting fuel-based emission factors into power-based or mileage-based emission factors:

[0075] (7)

[0076] (8)

[0077] Where FC is the fuel consumption rate (kg / h), P is the engine power (kW), and v is the speed (km / h).

[0078] Taking CO2 as an example, emission factors based on fuel consumption, mileage, and power can be calculated. These factors include the emission factors of ships under different operating conditions, such as... Figure 4 As shown, ship emission factors under different loads are as follows: Figure 5 As shown.

[0079] Taking CO2 as an example, the emission factors based on fuel consumption and power and driving distance are calculated and shown in Table 4.

[0080] Table 4. Emission factors of CO2 under different forms

[0081] name Departure Cruise 25% Cruise 50% 75% cruise 90% cruise Maneuvering docking Based on fuel consumption 390.5±41.6 645.7±3.5 980.8±5.1 123.3±5.9 148.3±13.0 128.8±9.8 458.8±42.8 Based on ship power 609.5 ±65.0 638.1±35.0 612.5±32.0 587.5±28.0 627.9±55.0 589.9±45.0 621.1±58.0

[0082] Step 4: Obtain the ship emission factor under steady-state operating conditions for this load by controlling the ship's speed to maintain a stable speed during navigation: Taking the relationship between engine load and speed in Table 3 as an example, various ship parameters and pollutant data under the target load are collected by controlling the ship's speed, and the emission factor based on the ship's speed is calculated by combining equations (4) and (8). Figure 6 As shown, the emission factors for each regulatory operating condition point of the vessel type with the working load that is not easily obtained can be obtained.

[0083] The above embodiments are preferred embodiments of the present invention, but the implementation of the present invention is not limited to the above embodiments. Any other technical solutions that can be obtained through logical analysis, reasoning or limited experiments without departing from the spirit and principle of the present invention are included within the protection scope of the present invention.

Claims

1. A method for measuring ship emission factors based on load-speed conversion relationship, characterized in that, Includes the following steps: The relationship between the regulatory operating point and the speed is constructed by formula, and the four steady-state operating conditions in the test cycle of the ship engine are converted into speed. The ship was tested using a self-built emission testing system to collect gaseous pollutants and particulate matter during the ship's operation. After converting the four regulatory operating conditions, actual ship tests were conducted at the corresponding speeds. The data were recorded, analyzed, and calculated to obtain the ship emission factors based on different speeds under the actual ship test. By constructing a relational formula, for ship types where it is difficult to obtain the ship's working load, the ship's emission factor under different loads can be obtained by controlling the speed.

2. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The relationship between the regulatory operating point and speed is constructed using a formula, specifically as follows: The relationship between engine load and main engine speed is as follows: ; Where RPM is the main engine speed, RPM ( R () represents the rated speed, and ENL represents the engine load at the steady-state operating point; The relationship between ship speed and main engine speed is as follows: ; Where V is the ship's speed in km / h; P is the propeller pitch, which refers to the distance the propeller propels per revolution in a solid environment; RPM is the engine speed; S R The slip ratio refers to the ratio of the theoretical propeller speed np to the actual propeller speed V. P The ratio of the difference to the theoretical propeller speed: ; Where n is the propeller rotational speed; P is the propeller pitch; V P This is the propeller's advance speed; The relationship between engine speed and engine load at the regulatory operating point is as follows: .

3. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The four steady-state operating conditions are as follows: referring to the international mainstream ISO-8178 marine engine test cycle, the engine load steady-state operating condition test points of 25%, 50%, 75%, and 100% are added, with corresponding weight factors of 0.2, 0.5, 0.15, and 0.15, respectively. Each test condition lasts for at least 20 minutes to ensure that the engine enters a stable state.

4. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The method of converting the four steady-state operating conditions in the test cycle of a ship engine into speed is as follows: the steady-state operating conditions with engine loads of 25%, 50%, 75%, and 100% are substituted into the corresponding formulas to convert them into speed.

5. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The self-built emission testing system is based on portable exhaust emission equipment and also includes: Dekati jet diluter, HY-100WS high-load particulate matter collector, SUMMA canister, AC-GC MS2000 atmospheric volatile organic compound monitoring system, and SEMTECH-DS vehicle exhaust gas analysis system.

6. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The gaseous pollutants and particulate matter collected during ship operation include: CO2, CO, NO, NO2, THC, PM, and SO2.

7. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The ship's operating parameters include: main engine power, speed, rotational speed, fuel consumption, exhaust flow rate, and exhaust temperature.

8. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The aforementioned method for calculating ship emission factors, based on fuel-based emission factors, can eliminate the influence of different engine power levels. ; EF i ( Fuel ) represents the fuel consumption-based emission factor of pollutant i, in g / kg·fuel; Δm i The emission mass increment of pollutant i relative to the background value during the measurement period is expressed in grams. x f Carbon content per unit mass of fuel, in g / kg·fuel; C i Let be the mass concentration of carbon in pollutant i in the exhaust gas. i = CO2, CO, HC, OC + EC; The formulas for converting fuel-based emission factors into power-based and mileage-based emission factors are as follows: ; Where FC is the fuel consumption rate (kg / h), P is the engine power (kW), and v is the speed (km / h).

9. The method for measuring ship emission factors based on load-speed conversion relationship according to claim 1, characterized in that, The aforementioned formula for constructing the relationship, which obtains the ship emission factor under different loads by controlling the speed, specifically involves: solving for the corresponding ship speed through the relationship between engine load and ship speed, and substituting this ship speed into the emission factor calculation formula based on mileage to obtain the emission factor for ship types that are difficult to obtain based on the ship's working load.

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