Effects of fuel temperature on injection performance of an EUP system

2017 ◽  
Vol 233 (3) ◽  
pp. 671-686
Author(s):  
Fushui Liu ◽  
Ruo Hu ◽  
Yikai Li ◽  
Ziming Yang ◽  
Hongming Xu
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Great Influence ◽  
Injection Rate ◽  
Needle Valve ◽  
Engine Fuel ◽  
Fuel Temperature ◽  
Closing Time ◽  
Fuel Supply ◽  
Injection Quantity

The fuel temperature has a great influence on the characteristics of an electronic unit pump (EUP) system, especially on the injection performance. This paper studies the regularity of the high-pressure fuel supply system performance at different fuel temperatures. The injection quantity, the injection rate, the fuel pressure, and the needle lift were measured by the EUP system test bench. Investigation results showed that, with the increase of fuel temperature, the injection quantity and maximum injection rate decreased, the time of start injection was delayed, and the peak fuel pressure value decreased. For the needle valve, as the temperature was raised its closing time was advanced at low speed conditions but delayed at high speed conditions. In addition, the empirical equations for the fuel temperature effects on the circulating fuel injection quantity and peak pressure are proposed by the experimental test and simulation data. This study will help to further apply and study the engine, and provide a reference for engine fuel supply control system design.

scholarly journals Vortex flow and cavitation in diesel injector nozzles

2008 ◽  
Vol 610 ◽  
pp. 195-215 ◽  
Author(s):  
A. ANDRIOTIS ◽  
M. GAVAISES ◽  
C. ARCOUMANIS
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Fuel Injector ◽  
Flowing Liquid ◽  
Injection Quantity ◽  
Dimensional Reconstruction ◽  
Real Size

Flow visualization as well as three-dimensional cavitating flow simulations have been employed for characterizing the formation of cavitation inside transparent replicas of fuel injector valves used in low-speed two-stroke diesel engines. The designs tested have incorporated five-hole nozzles with cylindrical as well as tapered holes operating at different fixed needle lift positions. High-speed images have revealed the formation of an unsteady vapour structure upstream of the injection holes inside the nozzle volume, which is referred to as ‘string-cavitation’. Computation of the flow distribution and combination with three-dimensional reconstruction of the location of the strings inside the nozzle volume has revealed that strings are found at the core of recirculation zones; they originate either from pre-existing cavitation sites forming at sharp corners inside the nozzle where the pressure falls below the vapour pressure of the flowing liquid, or even from suction of outside air downstream of the hole exit. Processing of the acquired images has allowed estimation of the mean location and probability of appearance of the cavitating strings in the three-dimensional space as a function of needle lift, cavitation and Reynolds number. The frequency of appearance of the strings has been correlated with the Strouhal number of the vortices developing inside the sac volume; the latter has been found to be a function of needle lift and hole shape. The presence of strings has significantly affected the flow conditions at the nozzle exit, influencing the injected spray. The cavitation structures formed inside the injection holes are significantly altered by the presence of cavitation strings and are jointly responsible for up to 10% variation in the instantaneous fuel injection quantity. Extrapolation using model predictions for real-size injectors operating at realistic injection pressures indicates that cavitation strings are expected to appear within the time scales of typical injection events, implying significant hole-to-hole and cycle-to-cycle variations during the corresponding spray development.

Simulation and Measurement of Fuel Injection Quantity Based on TB4P

2014 ◽  
Vol 26 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Dongmin Li ◽  
◽  
Jianzhong Zhang ◽  
Jianjun Yuan ◽  
FancanGuo ◽  
...  
Keyword(s):  
Relative Error ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Valve Lift ◽  
Needle Valve ◽  
Fuel Injector ◽  
Injection Pump ◽  
Injection Quantity ◽  
Fuel Injection Pump ◽  
Fuel Injection Pressure

In order to improve the measurement accuracy of fuel injection quantity based on Test Bench for fuel injection Pump (abbr. TB4P), on the basis of the function between needle valve lift and fuel injection quantity, two-level pressure adjustment module, which combines proportional flow rate valve with pressure sensor and takes advantage of spring of fuel injector, is used to control the outlet pressure of fuel injection pump, which results in the fuel injection pressure stably. Fuel injection pump and fuel injector are modeled by use of HCD of AMESim, and the system model of fuel injection quantity measurement is built. Simulation curve of fuel injection quantity is got by AMESim, which is compared with the curve of standard fuel injection quantity according to relative error. The results show that the relative error from the data of simulation system is smaller, so the methods of measurement and simulation in this paper are effective.

scholarly journals Research On Fuel Compensation Control of High-pressure Common-Rail Diesel Engine Based On Crankshaft Segment Signals

2021 ◽  
Author(s):  
Yuhua Wang ◽  
Guiyong Wang ◽  
Guozhong Yao ◽  
Lizhong Shen ◽  
Shuchao He
Keyword(s):  
High Pressure ◽  
Diesel Engine ◽  
Fuel Injection ◽  
Common Rail ◽  
Engine Fuel ◽  
Quantization Method ◽  
Software Module ◽  
Fuel Supply ◽  
Compensation Control ◽  
High Pressure Common Rail

Abstract This paper studies the high-pressure common-rail diesel engine fuel supply compensation based on crankshaft fragment signals in order to improve the uneven phenomenon of diesel engine fuel supply and realize high efficiency and low pollution combustion. The experiments were conducted on a diesel engine with the model of YN30CR. Based on the characteristics of crankshaft fragment signals, the proportional integral (PI) control algorithm was used to quantify the engine working nonuniformity and extract the missing degree of fuel injection. The quantization method of each cylinder working uniformity and algorithm of fuel compensation control (FOC) based on crankshaft fragment signal were established, and the control strategy of working uniformity at different operating conditions was put forward. According to the principle of FOC control, a FOC control software module for ECU was designed. The FOC software module was simulated on ASCET platform. The results show that: Compared with the traditional quantization method, the oil compensation information extracted from crankshaft fragment signal has stronger anti-interference and more accurate parameters. FOC algorithm can accurately reflect the engine's working nonuniformity, and the control of the nonuniformity is reasonable. The compensation fuel amount calculated by FOC is high consistency with the fuel supply state of each cylinder set by experiment, which meets the requirement of accurate fuel injection control of common-rail diesel engine.

scholarly journals Fuel Injector Testing Through Development of a New Test Rig

2019 ◽  
Vol 8 (9) ◽  
pp. 2904-2909
Keyword(s):  
Fuel Injection ◽  
Cylinder Liner ◽  
Heating System ◽  
Injection Rate ◽  
Engine Fuel ◽  
Exhaust Manifold ◽  
Fuel Injector ◽  
Test Rig ◽  
Recirculation System ◽  
Fuel Injection Rate

A modified version of fuel injector with higher injection capacity has been developed. To achieve this, the injector plunger diameter is increased to 11mm from current 9.5mm. A new test rig is developed to understand the functioning of the injector due to the changes incorporated. The new test rig is designed to test injector operation without burning the fuel. Since internal combustion is not present an external arrangement is required to run the engine. This is achieved through a 3-phase induction motor, which is coupled with the crankshaft of the engine. The injected fuel is collected form the cylinders and it is then recirculated. A fuel cooling circuit is also incorporated along with the fuel recirculation system to maintain the temperature of fuel at inlet of fuel pump. An oil heating system is installed in the test rig to maintain the viscosity of the oil by heating it. The required systems for driving the engine, fuel cooling and oil heating are implemented as per the design. The test is conducted on a 19 L diesel engine. Parts which are not required for this test like piston, piston rings, intake and exhaust manifold etc are removed from the engine. And the cylinder liner is blocked from below using a plate to facilitate the collection of injected fuel. Engine is made to run using the motoring rig at the rated speed of 1500 rpm for a duration of 250 hours. Instrumented push tubes are used to measure the push tube load. Push tube load is observed to be in the range of 2700 to 3100 lbf, which is high as compared to the earlier model of the injector. Fuel injection rate is obtained from the fuel collected from the cylinders. And the average fuel injection rate is observed as 0.116 to 2.35 kg/min. Thus, the increase in plunger diameter has led to an increase in fuel injection rate

Application of HFRT Methods to Diagnose the Technical Condition of High-Speed Marine Diesel Engines

2015 ◽  
Vol 236 ◽  
pp. 161-168
Author(s):  
Tomasz Lus
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Technical Condition ◽  
Injection System ◽  
Engine Fuel ◽  
Naval Academy ◽  
Marine Diesel

The paper presents problems related to testing of the technical condition of high-speed marine diesel engines that are not equipped with indicated valves, as it is in the case of larger medium-and low-speed marine internal combustion engines. In this case, in assessment of technical condition of engine fuel injection system and valve gear system a vibration signals (in time / angle domain) analysis modified method called HFRT (High Frequency Resonance Technique) can be used. This method indirectly helps also to evaluate the fuel combustion process in the engine cylinders. The paper presents the theoretical basis of a modified HFRT method, physical implementation of the marine diesel engine system’s analyzer used for marine engines testing built at the Institute of Construction and Operation of Ships at Polish Naval Academy (PNA) in Gdynia. The paper also includes a description of the vibration signal processing methodology and examples of measurements made in the ships conditions for a few selected types of engines.

Study of Fuel Temperature Effects on Fuel Injection, Combustion, and Emissions of Direct-Injection Diesel Engines

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Gong Chen
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Temperature Effects ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Rate ◽  
Fuel Temperature ◽  
Injection Parameters ◽  
Medium Speed

The influence of inlet liquid fuel temperature on direct-injection diesel engines can be noticeable and significant. The work in this paper investigates the effects of inlet fuel temperature on fuel-injection in-cylinder combustion, and output performance and emissions of medium-speed diesel engines. An enhanced understanding and simplified modeling of the variations in the main fuel-injection parameters affected by inlet fuel temperature are developed. The study indicates that the main injection parameters affected include the injection timing at the injector end relative to the injection-pump actuation timing, the fuel-injection rate, the fuel-injection duration, and the injection spray atomization. The primary fuel temperature effects on the injection parameters are from the fuel bulk modulus of elasticity and the density with the fuel viscosity less significant as the injector-nozzle flow is usually in a turbulent region. The developed models are able to predict the changes in the injection parameters versus the inlet fuel temperature. As the inlet fuel temperature increases, the nozzle fuel-injection-start timing is predicted to be relatively retarded, the injection rate is reduced, and the needle-lift duration is prolonged from the baseline. The variation trends of the engine outputs and emissions versus fuel temperature are analyzed by considering its consequent effect on in-cylinder combustion processes. It is predicted that raising fuel temperature would result in an increase in each of CO, HC, PM, and smoke emissions, and in a decrease in NOx, and may adversely affect the fuel efficiency for a general type of diesel engine at a full-load condition. The experimental results of the outputs and emissions from testing a medium-speed four-stroke diesel engine agreed with the trends analytically predicted. The understanding and models can be applied to compression-ignition direct-injection liquid fuel engines in general.

Study of Fuel Temperature Effects on Fuel Injection, Combustion and Emissions of Direct-Injection Diesel Engines

2003 ◽  
Author(s):  
Gong Chen
Keyword(s):  
Diesel Engines ◽  
Temperature Effects ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Rate ◽  
Fuel Temperature ◽  
Injection Parameters ◽  
Medium Speed ◽  
Performance And Emissions

The influence of inlet liquid fuel temperature on direct-injection diesel engines can be noticeable and significant. The work in this paper investigates the effects of inlet fuel temperature on fuel injection, in-cylinder combustion, and performance and emissions of medium-speed diesel engines. An enhanced understanding and simplified modeling of the variations in main fuel injection parameters affected by inlet fuel temperature are developed. The study indicates that the main affected injection parameters include the injector injection timings, the fuel injection rate, the fuel injection duration, and the injection spray atomization. The primary fuel temperature effects on the injection parameters are from the fuel bulk modulus of elasticity and the density with the fuel viscosity less significant as the injector nozzle flow is in a turbulent region. The developed models can predict the changes in the injection parameters versus fuel temperature. As inlet fuel temperature increases, the nozzle fuel-injection-start timing is predicted to be retarded, the injection rate to be reduced, and the needle-lift duration to be prolonged from the baseline. The variation trends of the engine performance and emissions versus fuel temperature are analyzed by considering its consequent effect on in-cylinder combustion processes. It is predicted that raising fuel temperature would result in an increase in CO, HC, PM and smoke emissions, and in a decrease in NOx. The experimental results of the output performance and emissions from testing a medium-speed four-stroke diesel engine agreed with the trends analytically predicted. The understanding and models developed can apply to compression-ignition direct-injection liquid fuel engines in general.

A study on the injection characteristics of a liquid-phase liquefied petroleum gas injector for air-fuel ratio control

2005 ◽  
Vol 219 (8) ◽  
pp. 1037-1046 ◽  
Author(s):  
Hansub Sim ◽  
Kangyoon Lee ◽  
Namhoon Chung ◽  
Myoungho Sunwoo
Keyword(s):  
Liquid Phase ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Vapour Phase ◽  
Injection Rate ◽  
Injection System ◽  
Driving Voltage ◽  
Liquefied Petroleum Gas ◽  
Fuel Temperature ◽  
Fuel Ratio

Liquefied petroleum gas (LPG) is widely used as a gaseous fuel in spark ignition engines because of its considerable advantages over gasoline. However, the LPG engine suffers a torque loss because the vapour-phase LPG displaces a larger volume of air than do gasoline droplets. In order to improve engine power as well as fuel consumption and air-fuel ratio control, considerable research has been devoted to improving the LPG injection system. In the liquid-phase LPG injection systems, the injection rate of an injector is affected by the fuel temperature, injection pressure, and driving voltage. When injection conditions change, the air-fuel ratio should be accurately controlled in order to reduce exhaust emissions. In this study, correction factors for the fuel injection rate are developed on the basis of fuel temperature, injection pressure, and injector driving voltage. A compensation method to control the amount of injected fuel is proposed for a liquid-phase LPG injection control system. The experimental results show that the liquid-phase LPG injection system works well over the entire range of engine speeds and load conditions, and the air-fuel ratio can be accurately controlled by using the proposed compensation algorithm.

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