The Experimental Study of the Plateau Performance of the F6L913 Diesel Engine

Transcription

1 Sensors & Transducers 2013 by IFSA The Experimental Study of the Plateau Performance of the F6L913 Diesel Engine 1 Weiming Zhang, 2 Jiang Li 1, 2 Dept. of Petroleum Supply Engineering, Logistical Engineering University, Chongqing, , China 1 Tel: , fax: , 2 Tel: , fax: zwm50262@163.com, lijiang830@163.com Received: 5 June 2013 /Accepted: 25 August 2013 /Published: 30 September 2013 Abstract: The FST2E engine test bed was applied to carry out the simulation tests of the F6L913 diesel engine s plateau performance, to obtain the data of the engine at different altitudes and in various conditions, including torque, power, fuel consumption rate and oil consumption, and to generate the external characteristic curve and the load characteristic curve of the engine by fitting. The test result shows that the engine power and torque is decreased by 15 % to 20 % and the fuel consumption rate is increased by 15 % to 30 % whenever the altitude is increased by 1000 m, and the higher the altitude is, the faster this increase rate becomes. The stable working range of the engine becomes narrower and drifts to the high revolution area. Copyright 2013 IFSA. Keywords: Engines, Plateau simulation test, External characteristic, Load characteristic, Data analysis. 1. Introduction The mobile pipeline can be used for oil transportation in the whole territory and under all weather conditions, so it is an important meaning for emergency oil transportation [1]. The prime motor of a certain type of pipeline pump unit uses the F6L913 air-cooled diesel engine, with the air intake way of natural aspiration. With the risen of elevation, the charging efficiency of the engine decreases, its working conditions become poor, its fuel consumption rate and oil consumption increases and its torque and power decreases. The decline in the power performance of the engine results in a reduction in the lift of the fuel pump and a decrease in the amount of oil, thus affecting the transportation performance of the pipeline. In order to make a quantitative analysis of the decreased performance of the diesel engine at different altitudes and under different working conditions, the engine test-bed experiment that simulates the plateau environment was made. 2. Test Device and Method 2.1. Test Device The object of the test is the diesel engine of the pump unit, and its main performance indicators are shown in Table 1 [2]: The experiment was made on the FST2E engine test bed which includes three parts, the engine bed system, the computer control system and the data acquisition system [3], with the butterfly valve as the air intake throttling part and the vacuum gauge to Article number P_

2 measure the vacuum degree of the intake system, to simulate the air-intake pressure of the engine at different altitudes by controlling the opening degree of the butterfly valve, while measuring the air inflow of the engine through the glass rotor flow meter. The simulation process of the intake of the device is shown in Fig. 1. Number of cylinders Rated power (kw) Table 1. F6L913 diesel engine performance parameters. Rated revolution (r/min) Maximum torque (N m) Rated fuel consumption (g / kw h) Piston displacement (L) Compression ratio : Fuels Connect the crankcase Fig. 1. The flow chart of the FST2E intake simulation: (1) - Oxygen bottles; (2) - Pressure reducing valve; (3/4) - Butterfly valve; (5) - Pressure stabilizing box; (6) - Temperature sensor; (7/8) - Vacuum gauge; (9) Filter; (10) - Sampling vacuum pump; (11) - Oxygen analyzer; (12) - Fuel mass flow meter; (13) Engine; (14) - Electric dynamometer; (15) - Exhaust gas analyzer; (16) - Opaque photometer Test Methods The experiment is made based on Performance Test Code for Road Vehicle Engines [4], Reliability Test Methods for Motor Vehicle Engines [5], Measurement Methods of Net Power for Automotive Engines [6] and other national standards Test Method of External Characteristic [7] Fix the opening degree of the engine throttle at 100 %, and measure power, torque, fuel consumption and fuel consumption rate and other parameters at the engine revolutions of 1300 r/min, 1400 r/min, 1500 r/min, 1600 r/min, 1700 r/min, 1800 r/min, 1900 r/min, 2000 r/min, 2100 r/min, 2200 r/min, 2300 r/min, 2400 r/min, 2500 r/min and 2600 r/min Test Method of Load Characteristic [8-9] Select the rotation speed of the engine at low speed (1400 r/min), medium speed (2000 r/min) and high speed (2400 r/min), and increase the load of the engine under the fixed revolutions, starting from 20 % of the load, and then gradually increase to the load of 30 %, 40 %, 50 %, 60 %, 70 %, 80 %, 90 % and 100 %, to separately measure the engine parameters under various loads such as engine power, fuel consumption rate, etc. 3. Test Results With the above methods, parameters of the engine such as power, torque, fuel consumption rate and fuel consumption working at the altitudes of 0 m, 2000 m, 2500 m, 3000 m, 3500 m, 4500 m and 5000 m were tested, and the related data were obtained. Method in Reference [10] was used to correct the power and torque and to obtain the external characteristic curves and the load characteristic curves of the engine at various altitudes, as shown in Fig. 2 to Fig Data Analysis Through the analysis of the external characteristic curve graphs 2 to 8, the engine of this type has the inflection points of a sharp drop in power and torque appear in the revolutions between 2400 r/min and 2500 r/min. In order to ensure the reliability of the data analysis, the data in the revolutions from 1300 r/min to 2400 r/min are to be analyzed. 188

3 Fig m External characteristic curve: Fig m External characteristic curves: Fig m External characteristic curve: Fig m External characteristic curve: 189

4 Fig m External characteristic curve: Fig m External characteristic curve: Fig m External characteristic curve: Fig m Load characteristic curve: 190

5 Fig m Load characteristic curve: Fig m Load characteristic curve: Fig m Load characteristic curve: Fig m Load characteristic curve: 191

6 Fig m Load characteristic curve: Fig m Load characteristic curve: 4.1. Impact on Power and Torque In order to obtain the variation rule for engine power and torque at different altitudes, calculating the decrease rate of the maximum power and torque as well as the minimum power and torque of the engine under various revolutions and at various altitudes, compared with the data of 0 m, and take the mean value, the data are shown in Table 2 below. The analysis of the data in Table 2 shows that with the rising of altitude, the power and torque provided by the engine have different degrees of decline, and the decline rate of the minimum power and torque is lower than that of the maximum power and torque; the altitude of 3000 m is an inflection point for the decline of the power and torque of this type of engine. When the altitude is lower than 3000 m, the engine power declines by about 12 % and the torque by about 14 % compared to the altitude of 0 m per 1000 m; when the altitude is higher than 3000 m, the engine power declines by about 20 % and the torque by about 17 % compared to the altitude of 0 m per 1000 m. Altitude has a great impact on the power and torque of this type of engine and the impact degree will be deepened and speeded up along with the rising of the altitude. Altitude (m) Maximum / minimum power (kw) Table 2. Variation rule for engine power and torque at different altitudes. Maximum / minimum power decline rate (%) Average power decline rate (%) Maximum / minimum torque (N m) Maximum / minimum torque decline rate (%) Average torque decline rate (%) 0 74/ / ,000 55/ / / / ,500 48/ / / / ,000 45/ / / / ,500 40/ / / / ,500 29/ / / / ,000 26/ / / /

7 4.2. Impact on the Fuel Consumption Rate Fig. 2 shows that the engine fuel consumption rate is basically stable at about 230 g / (kw h) at the altitude of 0 m and in the revolutions of less than 2400 r/min. By comparing with data in Table 3 and Curve 4 in Fig. 3 to Fig. 8, it can be seen that the rising of altitude, the decrease of atmospheric pressure and the decline of the charging coefficient result in the continuous rising of the engine s fuel consumption rate, and in the altitude of 5000 m, the fuel consumption will grow by %. By comparing Fig. 9 to Fig. 15, it is known that the engine fuel consumption rate is the highest in the case of low loads, which is followed by the case of medium load, and the increase of the fuel consumption rate in the case of the high-load area is minimal. The analysis of the relationship among curves 1, 2 and 3 in Fig. 9 to Fig. 15 also shows that the three fuel consumption curves are nearly parallel without intersection in the altitude of 0m, while there is at least one group among curve 1 and curve 2 or curve 2 and curve 3 at the other altitudes with an intersection. These present such a tendency that the higher the altitude is, the more frequently the cross curves becomes and the cross points appear in advance, e.g., as shown in Fig. 10. Only curve 1 and curve 2 are intersected, and the crossover point occurs in the vicinity of the power 45 kw, while in Fig. 12, the intersection occurs between both curve 1, curve 2 and curve 3, and the point of intersection of curves 1 and curve 2 occurs in the position of power 37 kw, which suggests that the engine fuel consumption increases under the same power and torque in the plateau situation, thus leading to the increase in the rate of fuel consumption Impact on the Engine s Stable Working Range As shown in Table 4, the maximum load is 38 kw when the altitude is 0m and the engine revolution number is 1400 r/min; the maximum load is 61 kw when the number of revolutions is 2000 r/min and the maximum load is 74 kw when the number of revolutions is 2400 r/min. With this as a standard, the following conclusions can be drawn from the comparison of the engine load characteristics at other altitudes, that is, every 1000 m increase in altitude will cause the maximum load of the engine to fall within the range of 10 % to 30 %, but its downward trend varies. In the case of 1400 r/min, the maximum load of the engine declines slowly in the beginning, but after the altitude is over 3500 m, a sharp decline occurs in the maximum load of the engine while in the case of 2000 r/min and 2400 r/min, the engine has the sharpest decline in the maximum load at the altitude from 2500 m to 3500 m. In addition, by comparing Curve 1 in Fig. 2 to Fig. 8, it can also be found that in the case of 1700 r/min to 1800 r/min, the inflection point is featured by first drop and then rise of the torque, and a phenomenon can be seen that the higher altitude is, the steeper the curve becomes, and the position of the inflection point moves to the high revolutions area. Altitude (m) Fuel consumption (g / kwh) Table 3. Variation rule for engine fuel consumption rate at different altitudes. Minimum fuel consumption rate (g / kwh) Maximum fuel consumption rate of growth (%) Minimum fuel consumption rate of growth (%) Average fuel consumption rate of growth (%) , , , , , , Altitude (m) 1400 r/min maximum load (kw) Table 4. Variation rule for engine load characteristics at different altitudes r/min maximum load (kw) 2400 r/min maximum load (kw) 1400 r/min load decline rate (%) 2000 r/min load decline rate (%) 2400 r/min load decline rate (%) , , , , ,

8 It follows that with the rising of the altitude, the effective power that the engine can provide is getting smaller and smaller, and when it drops to a certain level, the engine at the low revolution area will be unable to output enough power to get out of the stable working range, which results in the stable working range of the engine drifting to the high revolution area, i.e. the stable working range of the engine is narrowed. of 3000 m, the maximum power that the engine can obtain is only 27 kw and the fuel consumption increases dramatically and intersects with the load characteristics curve of 2000 r/min, at which the engine has drifted out of stable working range. In order to ensure the safe and stable operation of the engine, this type of engine must be improved accordingly after the altitude exceeds 3000 m, in order to improve its plateau adaptability. 5. Conclusions Through a series of simulation experiments of engine plateau performance, the rule of engine plateau performance decline is found and the external characteristic curve and the load characteristic curve are generated for engines. The following conclusions are drawn from the data analysis: The engine has a significant reduction in its power and torque, and its downward trend speeds up along with the rising of the altitude. The experiment shows that the altitude of 3000 m is the inflection point of the decline in the power and torque of this type of engine. In the case of lower than 3000 m, every 1000 m increase in the altitude will decrease the engine power and torque by approximately 10 % to 15 %; in the case of higher than 3000 m, every 1000 m increase will cause the engine power and torque to fall by approximately 15 % to 20 %. Fuel consumption increases, and the higher the altitude is, the greater the rate of growth becomes. The growth rate of the fuel at an altitude of 3500 m is maintained at an increase by 15 % for every 1000 m, and the rapid growth sharpens once exceeding 3500 m. The fuel consumption of the engine low load area has the highest growth rate, and the growth rate of the medium load area is higher than that of the high-load area. The stable working range of the engine narrows and drifts to the high revolution area. Take the revolution of 1400 r/min for example, in the altitude References [1]. W. M. Zhang, Introduction to Pipeline Engineering, Logistical Engineering University, [2]. J. N. Pu, The Military Pipeline, Logistical Engineering University, [3]. M. S. Wei, X. Q. Cheng, Y. L. He, etc., Development of Turbocharged Diesel Engine Plateau Performance Simulation Program, Internal Combustion Engine Engineering, Vol. 28, Issue 4, 2007, pp [4]. GB/T Automotive Engine Performance Test. [5]. GB/T , Automotive Engine Reliability Test Method. [6]. GB Automotive Engine Net Power Test Methods. [7]. Y. X. Huang, Introduction to Plateau Engine Performance Test and Study, CF Technology, Vol. 28, Issue 3, 2000, pp [8]. J. L. Lei, L. Z. Shen, Y. H. Bi, The study of Turbocharged Diesel Engine Performance at Different Altitudes, Small Internal Combustion Engine and Motorcycle, Vol. 34 Issue 6, 2005, pp [9]. L. Z. Shen, Y. Z. Yang, J. L. Lei, etc., Study of the Turbocharged Intercooled Diesel Engine Performance and Emissions at Different Altitudes, Internal Combustion Engine Journal, Vol. 24, Issue 3, 2006, pp [10]. S. H. Ren, R. X. Li, Calculation Simulation of the Diesel Engine Speed Characteristic in the Plateau Conditions, Internal Combustion Engine, Vol. 24, Issue 1, 2007, pp Copyright, International Frequency Sensor Association (IFSA). All rights reserved. ( 194