Marine main engine fuel injector working performance evaluation method considering different temperature conditions

Abstract

A marine main engine fuel injector working performance evaluation method considering different temperature conditions is characterized in that a marine main engine fuel injector working performance evaluation experiment table considering different working temperatures is built, and evaluation steps are as follows: a to-be-detected fuel injector is fixed on a bracket in an experiment box and is connected with a high-pressure hose; the temperature in the experiment box is adjusted and kept to reach a set value through the temperature control system, the temperature set value is switched according to a pre-selected gradient, and the oil stain area corresponding to each oil spraying hole is measured by measuring the valve opening pressure, the oil spraying quantity, the nozzle height and the oil stain area under different working temperature conditions. And calculating the working performance degradation coefficient of the marine main engine fuel injector to be detected by using the parameters, and judging the degree to which the working performance of the fuel injector is degraded and whether the fuel injector needs to be further maintained and replaced according to the value range of the degradation coefficient. Experiment conditions created by the method are closer to actual working conditions, and the method has important practical significance for guaranteeing stable operation of the ship main engine.

Description

Technical Field

[0001] The invention belongs to the technical field of ship equipment evaluation and maintenance, and in particular relates to a method for evaluating the working performance of a ship main engine injector under different working temperature conditions. Background Art

[0002] The ship's main engine is the power source for ship propulsion and is also the premise and guarantee for safe ship operation. As an important part of the main engine's fuel supply system, the injector's main function is to atomize the fuel at an appropriate pressure and injection angle and spray it into the combustion chamber to achieve efficient combustion. Its working performance directly affects the main engine's operating stability, fuel efficiency and emission characteristics.

[0003] During the testing and evaluation of the working performance of the marine main engine injector, the compressed air driven test bench provided by the main engine manufacturer cannot control the amount of pumped oil. In order to reduce the risk of the needle valve and valve seat in the injector getting stuck, the manufacturer generally does not provide atomization test functions. Moreover, most traditional methods are carried out at room temperature, and the impact of changes in working temperature on performance is not fully considered. This limitation leads to a deviation between the evaluation results and the actual working status, which in turn affects the accurate judgment of the health status of the injector.

[0004] One end of the injector is inserted into the combustion chamber and is directly exposed to the high-temperature gas. Although the cylinder head design of the main engine is equipped with a cooling medium circulation system to assist in cooling the injector, the injector still needs to experience a large temperature difference during the process of the main engine from cold start to full load operation. The plunger sleeve in the injector is a precision part and is sensitive to temperature changes. This temperature fluctuation has an important impact on the working performance of the injector.

[0005] Therefore, it is particularly important to develop a method for evaluating the performance of ship main engine injectors that can take into account different operating temperature conditions. This not only helps to accurately evaluate the performance of injectors under actual working conditions, but also provides a scientific basis for the maintenance and optimization of injectors, further improving the overall performance and operational safety of ship main engines. By introducing a systematic evaluation method that includes temperature change factors, the risk of failures caused by performance degradation can be significantly reduced, thereby enhancing the reliability and economy of ships. Summary of the invention

[0006] In order to solve the limitations and shortcomings of existing evaluation technical means, so as to more accurately evaluate the degree of degradation of the working performance of the ship main engine injector, the present invention proposes a ship main engine injector working performance evaluation test bench and method considering different temperature conditions. The specific technical solution is as follows:

[0007] A test bench for evaluating the working performance of a fuel injector of a ship main engine considering different temperature conditions, the test bench comprising: a camera, a test box, filter paper, a fuel injector to be evaluated, an explosion-proof heater, an explosion-proof temperature sensor, a high-pressure oil pipe, a ventilation pipe, a damper motor, a damper baffle, an explosion-proof ventilator, an adjustable quantitative fuel injection pump, a filter, an oil tank, a temperature transmitter, an adjustable bracket with a ruler, an explosion-proof shadowless lamp, a temperature controller, and a control station;

[0008] The test box has a transparent bottom plate and an openable front cover plate, and an adjustable bracket with a ruler is installed inside. The fuel injector to be evaluated and the explosion-proof temperature sensor are fixed on the bracket. The distance between the nozzle and the transparent bottom plate can be adjusted by the ruler on the bracket. Filter paper is laid on the transparent bottom plate directly below the nozzle. When the fuel injector sprays oil, the atomized oil droplets sprayed from each fuel injection hole on the nozzle will form a spray oil trace corresponding to a single fuel injection hole on the filter paper.

[0009] The control station is connected to the damper motor, explosion-proof ventilator, camera, temperature controller and adjustable quantitative fuel injection pump through signal cables to realize the interaction of data collection and control instructions;

[0010] The camera is calibrated with camera parameters and connected to the explosion-proof shadowless lamp through a signal cable, and can measure the area of ​​the spray oil trace corresponding to each spray hole on the filter paper and control the explosion-proof shadowless lamp to achieve on-demand lighting and brightness adjustment during the photo shooting process;

[0011] The temperature controller is connected to the temperature transmitter and the explosion-proof heater via a signal cable, thereby realizing feedback control of temperature regulation;

[0012] The temperature transmitter is connected to the explosion-proof temperature sensor via a signal cable to collect temperature signals;

[0013] The adjustable quantitative fuel injection pump is connected to the fuel injector to be evaluated and the filter through a high-pressure oil pipe and a hose respectively, and the filter is completely immersed in the oil in the oil tank to realize quantitative high-pressure oil suction and supply controlled manually or by a control station;

[0014] The damper baffle and explosion-proof ventilator are installed inside the ventilation duct. The damper motor controls the position of the damper baffle through the transmission mechanism. When the baffle is in the horizontal (solid line) position, the temperature balance function is realized, and the temperature in the test box can quickly reach the set value. When the baffle is in the vertical (dotted line) position, the ventilation and cooling function is realized, and fresh air enters from the gap around the openable front cover, and the residual oil mist in the test box will also be discharged;

[0015] The following steps are involved in evaluating the injector performance using the above test bench:

[0016] Step 1, simulate the working process of the ship main engine injector, the specific steps are: fix the injector to be evaluated on an adjustable bracket with a ruler, adjust the height h of the nozzle from the transparent bottom plate of the test box by the ruler, set the injection volume q through the control station after installing the high-pressure oil pipe, and automatically purge and store pressure, then lay filter paper directly under the nozzle, the control station issues an injection command and starts the camera and explosion-proof shadowless lamp, each nozzle on the injector forms an oil mark on the filter paper after injection, after the injection is completed, the control station collects the valve opening pressure fed back by the adjustable quantitative injection pump, controls the explosion-proof shadowless lamp to give the peak brightness, controls the camera to take pictures and calculates the oil mark area corresponding to each injection hole by calibrating the photography parameters;

[0017] Step 2: Test the operating parameters of the host injector under different temperature conditions. The specific steps are as follows: the control station communicates with the temperature controller, and the test box is heated and cooled with the cooperation of the explosion-proof heater and the explosion-proof ventilator, so that the temperature in the control box is between 30℃ and 150℃, and the injection test and data sampling are performed at intervals of 10℃ to obtain the corresponding valve opening pressure p under different working temperatures t and the corresponding oil trace areas s1, s2, ..., s of all k injection holes. k , repeating steps 1 and 2 continuously, obtaining multiple groups of valve opening pressures and nozzle oil trace areas corresponding to different injection heights, different injection volumes, and different working temperatures;

[0018] Step 3: Calculate the performance degradation coefficient ξ of the ship main engine injector under different working temperatures using the following formulas:

[0019] (1) Calculate intermediate results

[0020] s max =max{s1, s2, ..., s k} (1)

[0021] s min =min{s1, s2, ..., s k} (2)

[0022] s all =s1+s2+…+s k (3)

[0023]

[0024] Among them, s max is the maximum value of the oil trace area of ​​a single nozzle, s min is the minimum value of the oil trace area of ​​a single nozzle, s all is the sum of the oil trace areas of all nozzle holes, is the average value of the oil mark area of ​​the nozzle hole, σ s is the standard deviation of the oil mark area of ​​the nozzle hole;

[0025] (2) Calculation of degradation coefficient

[0026]

[0027] Among them, h is the injection height, q is the injection amount, t is the working temperature, and p is the valve opening pressure;

[0028] Step 4: Evaluate the working performance of the ship's main engine injector:

[0029] When the fuel injector performance degradation coefficient ξ∈(0,1], it indicates that the fuel injector is working normally; when the fuel injector performance degradation coefficient ξ∈(1,3], it indicates that the fuel injector performance has deteriorated to the extent that it needs maintenance, and the gasket, spring or nozzle should be replaced as soon as possible; when the fuel injector performance degradation coefficient ξ∈(3,+∞], it indicates that the fuel injector performance has seriously deteriorated, and the parts should be replaced immediately or the whole set should be replaced with a new one.

[0030] The beneficial effects of the present invention are:

[0031] (1) Taking the operating temperature into account makes the evaluation process closer to the actual working conditions of the main engine injection machine, thereby obtaining more accurate evaluation results;

[0032] (2) The degradation coefficient can be used to quickly determine the degree of degradation of the working performance of the ship's main engine injector, and corresponding measures can be given according to the range of degradation coefficient values;

[0033] (3) The experimental platform has a variety of adjustment methods and can adapt to the testing requirements of different types of injectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention relates to a schematic diagram of a system for evaluating the working performance of a ship main engine injector taking into account different temperature conditions; DETAILED DESCRIPTION

[0035] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0036] First, if Figure 1As shown, a test bench for evaluating the working performance of a ship main engine injector considering different temperature conditions is constructed, and the test bench comprises: a camera (1), a test box (2), a filter paper (3), an injector to be evaluated (5), an explosion-proof heater (6), an explosion-proof temperature sensor (7), a high-pressure oil pipe (8), a ventilation pipe (9), a damper motor (10), a damper baffle (11), an explosion-proof ventilator (12), an adjustable quantitative injection pump (13), a filter (14), an oil tank (15), a temperature transmitter (16), an adjustable bracket with a scale (17), an explosion-proof shadowless lamp (18), a temperature controller (19), and a control station (20);

[0037] The test box (2) has a transparent bottom plate and an openable front cover plate, and is internally provided with an adjustable bracket (17) with a scale, on which the fuel injector (5) to be evaluated and an explosion-proof temperature sensor (7) are fixed, and the distance between the nozzle and the transparent bottom plate can be adjusted by the scale on the bracket, and filter paper (3) is laid on the transparent bottom plate directly below the nozzle, and when the fuel injector sprays oil, the atomized oil droplets sprayed from each fuel injection hole on the nozzle will form a spray oil mark (4) corresponding to a single fuel injection hole on the filter paper;

[0038] The control station (20) is connected to the damper motor (10), the explosion-proof ventilator (12), the camera (1), the temperature controller (19) and the adjustable quantitative fuel injection pump (13) via a signal cable to achieve interaction between data collection and control instructions;

[0039] The camera (1) is calibrated with camera parameters and connected to an explosion-proof shadowless lamp (18) via a signal cable, so as to measure the area of ​​the spray oil trace corresponding to each spray hole on the filter paper and control the explosion-proof shadowless lamp (18) to achieve on-demand lighting and brightness adjustment during the photographing process;

[0040] The temperature controller (19) is connected to the temperature transmitter (16) and the explosion-proof heater (6) via a signal cable, thereby realizing feedback control of temperature regulation;

[0041] The temperature transmitter (16) is connected to the explosion-proof temperature sensor (7) via a signal cable to collect temperature signals;

[0042] The adjustable quantitative fuel injection pump (13) is connected to the fuel injector (5) to be evaluated and the filter (14) through a high-pressure oil pipe (8) and a hose, respectively. The filter (14) is completely immersed in the oil in the oil tank (15), so as to realize quantitative high-pressure oil suction and supply controlled manually or by a control station;

[0043] The damper baffle (11) and the explosion-proof ventilator (12) are installed inside the ventilation pipe (9). The damper motor (10) controls the position of the damper baffle (11) through a transmission mechanism. When the baffle (11) is in a horizontal (solid line) position, a temperature balancing function is realized, and the temperature in the test box can quickly reach a set value. When the baffle (11) is in a vertical (dotted line) position, a ventilation cooling function is realized, and fresh air enters from the gap around the openable front cover, and residual oil mist in the test box is also discharged;

[0044] Next, the job performance evaluation includes the following steps:

[0045] Step 1, simulating the working process of the ship main engine injector, the specific steps are: fix the injector to be evaluated (5) on an adjustable bracket (17) with a ruler, adjust the height h of the nozzle from the transparent bottom plate of the test box by the ruler, after installing the high-pressure oil pipe (8), set the injection amount q through the control station (20) and perform automatic air purge and pressure accumulation, then lay the filter paper (3) directly below the nozzle, the control station (20) issues an injection command and starts the camera (1) and the explosion-proof shadowless lamp (18), each nozzle on the injector forms an oil mark on the filter paper after injection, after the injection is completed, the control station (20) collects the valve start pressure fed back by the adjustable quantitative injection pump (13), controls the explosion-proof shadowless lamp (18) to give a peak brightness, controls the camera (1) to take pictures and calculates the oil mark area corresponding to each injection hole by calibrating the photography parameters;

[0046] Step 2, testing the operating parameters of the host fuel injector under different temperature conditions, specifically, the control station (20) communicates with the temperature controller (19), and with the cooperation of the explosion-proof heater (6) and the explosion-proof ventilator (12), the test box (2) is heated and cooled, so that the temperature in the control test box (2) is within the range of 30°C-150°C, and the injection test and data sampling are performed at intervals of 10°C, so as to obtain the corresponding valve opening pressure p under different working temperature conditions and the corresponding oil trace areas s1, s2, ..., s of all k fuel injection holes. k , repeating steps 1 and 2 continuously, obtaining multiple groups of valve opening pressures and nozzle oil trace areas corresponding to different injection heights, different injection volumes, and different working temperatures;

[0047] Step 3: Calculate the performance degradation coefficient ξ of the ship main engine injector under different working temperatures using the following formulas:

[0048] (1) Calculate intermediate results

[0049] s max =max{s1, s2, ..., s k} (1)

[0050] s min=min{s1, s2, ..., s k} (2)

[0051] s all =s1+s2+…+s k (3)

[0052]

[0053] Among them, s max is the maximum value of the oil trace area of ​​a single nozzle, s min is the minimum value of the oil trace area of ​​a single nozzle, s all is the sum of the oil trace areas of all nozzle holes, is the average value of the oil mark area of ​​the nozzle hole, σ s is the standard deviation of the oil mark area of ​​the nozzle;

[0054] (2) Calculation of degradation coefficient

[0055]

[0056] Among them, h is the injection height, q is the injection amount, t is the working temperature, and p is the valve opening pressure;

[0057] Step 4: Evaluate the working performance of the ship's main engine injector:

[0058] When the fuel injector performance degradation coefficient ξ∈(0,1], it indicates that the fuel injector is working normally; when the fuel injector performance degradation coefficient ξ∈(1,3], it indicates that the fuel injector performance has deteriorated to the extent that it needs maintenance, and the gasket, spring or nozzle should be replaced as soon as possible; when the fuel injector performance degradation coefficient ξ∈(3,+∞], it indicates that the fuel injector performance has seriously deteriorated, and the parts should be replaced immediately or the whole set should be replaced with a new one.

Claims

1. A method for evaluating the working performance of a ship main engine injector considering different temperature conditions, characterized in that: Firstly, a test bench for evaluating the working performance of a ship main engine fuel injector considering different temperature conditions is built, and the test bench comprises: a camera (1), a test box (2), a filter paper (3), a fuel injector to be evaluated (5), an explosion-proof heater (6), an explosion-proof temperature sensor (7), a high-pressure oil pipe (8), a ventilation pipe (9), a damper motor (10), a damper baffle (11), an explosion-proof ventilator (12), an adjustable quantitative fuel injection pump (13), a filter (14), a fuel tank (15), a temperature transmitter (16), an adjustable bracket with a scale (17), an explosion-proof shadowless lamp (18), a temperature controller (19), and a control station (20); The test box (2) has a transparent bottom plate and an openable front cover plate, and is internally provided with an adjustable bracket (17) with a scale, on which the fuel injector (5) to be evaluated and an explosion-proof temperature sensor (7) are fixed, and the distance between the nozzle and the transparent bottom plate can be adjusted by the scale on the bracket, and filter paper (3) is laid on the transparent bottom plate directly below the nozzle, and when the fuel injector sprays oil, the atomized oil droplets sprayed from each fuel injection hole on the nozzle will form a spray oil mark (4) corresponding to a single fuel injection hole on the filter paper; The control station (20) is connected to the damper motor (10), the explosion-proof ventilator (12), the camera (1), the temperature controller (19) and the adjustable quantitative fuel injection pump (13) via a signal cable to achieve interaction between data collection and control instructions; The camera (1) is calibrated with camera parameters and connected to an explosion-proof shadowless lamp (18) via a signal cable, so as to measure the area of ​​the spray oil trace corresponding to each spray hole on the filter paper and control the explosion-proof shadowless lamp (18) to achieve on-demand lighting and brightness adjustment during the photographing process; The temperature controller (19) is connected to the temperature transmitter (16) and the explosion-proof heater (6) via a signal cable, thereby realizing feedback control of temperature regulation; The temperature transmitter (16) is connected to the explosion-proof temperature sensor (7) via a signal cable to collect temperature signals; The adjustable quantitative fuel injection pump (13) is connected to the fuel injector (5) to be evaluated and the filter (14) through a high-pressure oil pipe (8) and a hose, respectively. The filter (14) is completely immersed in the oil in the oil tank (15), so as to realize quantitative high-pressure oil suction and supply controlled manually or by a control station; The damper baffle (11) and the explosion-proof ventilator (12) are installed inside the ventilation pipe (9). The damper motor (10) controls the position of the damper baffle (11) through a transmission mechanism. When the baffle (11) is in a horizontal (solid line) position, a temperature balancing function is realized, and the temperature in the test box can quickly reach a set value. When the baffle (11) is in a vertical (dotted line) position, a ventilation cooling function is realized, and fresh air enters from the gap around the openable front cover, and residual oil mist in the test box is also discharged; Job performance evaluation includes the following steps: Step 1, simulating the working process of the ship main engine injector, the specific steps are: fix the injector to be evaluated (5) on an adjustable bracket (17) with a ruler, adjust the height h of the nozzle from the transparent bottom plate of the test box by the ruler, after installing the high-pressure oil pipe (8), set the injection amount q through the control station (20) and perform automatic air purge and pressure accumulation, then lay the filter paper (3) directly below the nozzle, the control station (20) issues an injection command and starts the camera (1) and the explosion-proof shadowless lamp (18), each nozzle on the injector forms an oil mark on the filter paper after injection, after the injection is completed, the control station (20) collects the valve start pressure fed back by the adjustable quantitative injection pump (13), controls the explosion-proof shadowless lamp (18) to give a peak brightness, controls the camera (1) to take pictures and calculates the oil mark area corresponding to each injection hole by calibrating the photography parameters; Step 2, testing the operating parameters of the host fuel injector under different temperature conditions, specifically, the control station (20) communicates with the temperature controller (19), and with the cooperation of the explosion-proof heater (6) and the explosion-proof ventilator (12), the test box (2) is heated and cooled, so that the temperature in the control test box (2) is within the range of 30°C-150°C, and the injection test and data sampling are performed at intervals of 10°C, so as to obtain the corresponding valve opening pressure p under different working temperature conditions and the corresponding oil trace areas s1, s2, ..., s of all k fuel injection holes. k , repeating steps 1 and 2 continuously, obtaining multiple groups of valve opening pressures and nozzle oil trace areas corresponding to different injection heights, different injection volumes, and different working temperatures; Step 3: Calculate the performance degradation coefficient ξ of the ship main engine injector under different working temperatures using the following formulas: (1) Calculate intermediate results s max =max{s1,s2,…,s k } (1) s min =min{s1,s2,…,s k } (2) s all =s1+s2+…+s k (3) Among them, s max is the maximum value of the oil trace area of ​​a single nozzle, s min is the minimum value of the oil trace area of ​​a single nozzle, s all is the sum of the oil trace areas of all nozzle holes, is the average value of the oil mark area of ​​the nozzle hole, σ s is the standard deviation of the oil mark area of ​​the nozzle; (2) Calculation of degradation coefficient Among them, h is the injection height, q is the injection amount, t is the working temperature, and p is the valve opening pressure; Step 4: Evaluate the working performance of the ship's main engine injector: When the fuel injector performance degradation coefficient ξ∈(0,1], it indicates that the injector is working normally; when the fuel injector performance degradation coefficient ξ∈(1,3], it indicates that the fuel injector performance has deteriorated to the extent that it needs maintenance, and the gasket, spring or nozzle should be replaced as soon as possible; when the fuel injector performance degradation coefficient ξ∈(3,+∞], it indicates that the fuel injector performance has seriously deteriorated, and the parts should be replaced immediately or the entire set should be replaced.

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