Development of Double Gear Fuel Pump for Heat Management Improvement

Author(s):  
Yasushi Matsunaga ◽  
Noriko Morioka ◽  
Seiei Masuda ◽  
Masahiro Kurosaki

A unique double gear fuel pump system with operation mode switching capability for aircraft engines was developed to solve the heat management problem of current high efficiency turbofan engines and improve specific fuel consumption (SFC). Mode switching from parallel operations to series operations was found to reduce the discharge flow and pump work to nearly half. This resulted in the reduction of the rise in fuel temperature due to the fuel recirculation at the high altitude low Mach number flight condition. Air cooled oil cooler (ACOC) is usually required for sufficient oil cooling at descent or approach flight conditions. Since fuel consumption at those conditions is not very high, most of the gear pump discharge fuel flow proportional to the engine speed is returned to the fuel pump inlet resulting in significant heating. The ACOC that provides additional cooling capability degrades SFC due not only to the increased weight but also to the wasted fan discharge air. By reducing fuel temperature rise at the pump at those flight conditions, the necessity of ACOC may be eliminated. Further, it is shown that a reduction by half of the double gear pump weight can be achieved by increasing pump speed twice without incurring a durability penalty. Extensive tests showed sufficient steady state pump performance, switching characteristics, and durability.

Author(s):  
Yasushi Matsunaga ◽  
Noriko Morioka ◽  
Seiei Masuda ◽  
Masahiro Kurosaki

A unique double gear fuel pump system with operation mode switching capability for aircraft engines was developed to solve the heat management problem of current high efficiency turbofan engines and improve Specific Fuel Consumption (SFC). Mode switching from parallel operations to series operations was found to reduce the discharge flow and pump work to nearly half. This resulted in the reduction of the rise in fuel temperature due to the fuel re-circulation at the high altitude low Mach number flight condition. Air Cooled Oil Cooler (ACOC) is usually required for sufficient oil cooling at decent or approach flight conditions. Since fuel consumption at those conditions is not very high, most of the gear pump discharge fuel flow proportional to the engine speed is returned to the fuel pump inlet resulting in significant heating. The ACOC that provides additional cooling capability degrades SFC due to not only increased weight but also wasted fan discharge air. By reducing fuel temperature rise at the pump at those flight conditions, the necessity of ACOC may be eliminated. Further, it is shown that a reduction by half of the double gear pump weight can be achieved by increasing pump speed twice (2x) without incurring a durability penalty. Extensive tests showed sufficient steady state pump performance, switching characteristics, and durability.


Author(s):  
Noriko Morioka ◽  
Hitoshi Oyori

This paper describes the system design of an electric motor-driven fuel pump system for the MEE (More Electric Engine). The MEE is a new aircraft engine system concept which will reduce fuel burn and CO2 emissions, and improve engine safety, reliability and maintainability. At the initial concept design stage of the MEE, a feasibility study indicated that the electric fuel pump system helped improve engine efficiency. The selected fuel pump system configuration for the MEE was a fixed displacement gear pump system, the speed of which is controlled by an electric motor. Simplification of the fuel system will be expected because the electric gear pump itself is used as a metering device, but there are several technical challenges which should be overcome to realize the system. One of the technical challenges involves ensuring fuel metering accuracy via motor speed control. To address the issue, studies of the fuel flow rate feedback system were performed. A novel flow feedback system was investigated and the potential to ensure metering accuracy was confirmed. The other technical challenge is the wide speed range operation of the gear pump system. If only a single electric gear pump is used in the MEE system, the pump should accommodate a speed range of 5 to 100% because the ground starting flow rate is about 5% of the maximum flow. Operation at such low speeds is significantly harsh for the LP pump pressurizing capability and bearing film lubrication. However, optimized pump performance and operational condition were established, and it is expected that a single pump system, in which both LP and HP pumps are directly motor-driven via a single shaft, can be constructed. In addition, there is a technical challenge involved in supplying electrical power to the pump motor during the windmill engine start-up. The system design focused on the above technical challenges, and the consequent feasibility of the simplified MEE fuel pump system construction was confirmed.


Author(s):  
Hui Liu ◽  
Rui Liu ◽  
Riming Xu ◽  
Lijin Han ◽  
Shumin Ruan

Energy management strategies are critical for hybrid electric vehicles (HEVs) to improve fuel economy. To solve the dual-mode HEV energy management problem combined with switching schedule and power distribution, a hierarchical control strategy is proposed in this paper. The mode planning controller is twofold. First, the mode schedule is obtained according to the mode switch map and driving condition, then a switch hunting suppression algorithm is proposed to flatten the mode schedule through eliminating unnecessary switch. The proposed algorithm can reduce switch frequency while fuel consumption remains nearly unchanged. The power distribution controller receives the mode schedule and optimizes power distribution between the engine and battery based on the Radau pseudospectral knotting method (RPKM). Simulations are implemented to verify the effectiveness of the proposed hierarchical control strategy. For the mode planning controller, as the flattening threshold value increases, the fuel consumption remains nearly unchanged, however, the switch frequency decreases significantly. For the power distribution controller, the fuel consumption obtained by RPKM is 4.29% higher than that of DP, while the elapsed time is reduced by 92.53%.


Author(s):  
Qinglian Chen ◽  
Bitao Yao ◽  
Duc Truong Pham

Abstract For the realization of environmental protection and resource conservation, remanufacturing is of great significance. Disassembly is a key step in remanufacturing, the disassembly line system is the main scenario for product disassembly, usually consisting of multiple workstations, and has prolific productivity. The application of the robots in the disassembly line will eliminate various problems caused by manual disassembly. Moreover, the disassembly line balancing problem (DLBP) is of great importance for environmental remanufacturing. In the past, disassembly work was usually done manually with high cost and relatively low efficiency. Therefore, more and more researches are focusing on the automatic DLBP due to its high efficiency. This research solves the sequence-dependent robotic disassembly line balancing problem (SDRDLBP) with multiple objectives. It considers the sequence-dependent time increments and requires the generated feasible disassembly sequence to be assigned to ordered disassembly workstations according to the specific robotic workstation assignment method. In robotic DLBP, due to the special characteristics of robotic disassembly, we need to consider the moving time of the robots’ disassembly path during the disassembly process. This is also the first time to consider sequence-dependent time increments while considering the disassembly path of the robots. Then with the help of crossover and mutation operators, multi-objective evolutionary algorithms (MOEAs) are proposed to solve SDRDLBP. Based on the gear pump model, the performance of the used algorithm under different cycle times is analyzed and compared with another two algorithms. The average values of the HV and IGD indicators have been calculated, respectively. The results show the NSGA-II algorithm presents outstanding performance among the three MOEAs, and hence demonstrate the superiority of the NSGA-II algorithm.


Joint Rail ◽  
2003 ◽  
Author(s):  
H. Moghbelli ◽  
Y. Gao ◽  
R. Langari ◽  
M. Ehsani

Due to the consideration of fragile security, and longer check-in times and inconveniences due to increased air travel security examination since September 11th 2001, more and more people have turn to ground transportation. Unfortunately, the inefficient, environment-unfriendly and unsafe passenger cars and buses are the only choices available for middle distance trips. Development of high efficiency, clean and high speed railroad passenger transportation system has become more necessary to overcome this weak link. In this paper, the applicability of hybrid drive train technologies for middle-distance passenger train locomotives will be investigated. A systematic design of the diesel based hybrid locomotive helps to increase efficiency, improve fuel economy, reduce emissions and also reduce mass production costs. Furthermore, professional management and maintenance of railroad train locomotives make such new technologies more practical than for road vehicles. The success of such transportation system will have a great positive impact on our social activities, quality of life, energy supply, environment and economy. A diesel based hybrid electric locomotive (HEL) with batteries or an ultracapacitor is an option to reduce fuel consumption and emissions and provide better performance and fuel economy. The reduced fuel consumption helps reduce the amount of pollutants released. Engineering estimation indicate that emissions will be reduced by 70% and fuel efficiency will be increased by at least 30% in hybrid locomotives.


2016 ◽  
Vol 167 (4) ◽  
pp. 53-57
Author(s):  
Joanna LEWIŃSKA

The article presents results of a laboratory study on exhaust gas emission level from a marine diesel engine. The object of the laboratory study was a four-stroke marine diesel engine type Al 25/30 Sulzer, operated at a constant speed. The examination on the engine was carried out according to regulations of the Annex VI to MARPOL 73/78 Convention. The laboratory study consisted of 3 observations: the engine assumed to be operating without malfunctions, delay of the fuel injection by 5° of crankshaft angle in the second engine cylinder, and the leakage of the fuel pump on the second engine cylinder. Additionally, parameters of fuel consumption and thermodynamic parameters of the marine engine were measured during the research. Simulated malfunctions caused changes in total weighed NOx, CO, and CO2 emissions for all considered engine loads. All simulated malfunctions caused a small change in measured thermodynamic parameters of the engine. The engine operation with the delayed fuel injection and the fuel leakage in the fuel pump in one cylinder caused a decrease of NOx and CO emission level. Fuel leakage in the fuel pump causes the CO2 emission to decrease only at low engine load. Calculations of the weighed specific fuel consumption present a 1-2% change in the engine efficiency.


Author(s):  
Eurico Seabra ◽  
Jorge Costa ◽  
Hélder Puga ◽  
Celina Leão

Servo driven hydraulic power units have been implemented in some sectors of industry in order to counteract rising energy costs and reduce our ecological footprint. The advantages associated with the use of these technologies has motivated us to research a new control approach that allows its use independently, with reduced implementation costs and high efficiency. This investigation develops new solutions to concurrently implement and improve volumetric control methodology for oil-hydraulic power units, which aims to produce and provide strictly necessary hydraulic power to the actuators. The approach used is based on a balance of flows present in a hydraulic circuit, reducing the pressure ripple generated by the pumps, valves and actuators, using a hydraulic accumulator. The work begins with the mathematical modeling of a volumetric oil-hydraulic power unit, designed to demonstrate the concepts of the project, its components and the associated advantages. The definitions of the models presented are intended to exemplify the new control strategy and infer about the possibilities that arise from the use of this new methodology for power oil-hydraulic units. In order to carry out the research and conclude about the results of the simulations, two simulations were performed using MATLAB Simulink software for two distinct hydraulic circuits and their control strategy: resistive control and volume control with the use of a servo motor. In the resistive control, an internal gear pump driven by an induction motor with constant speed uses a pressure regulating valve to derive the excess of the flow to the reservoir. Despite their low efficiency, this type of assembly has very low costs and has a very good dynamic compared with traditional volumetric drive systems, avoiding the use of dedicated engineering. The volumetric control makes use of an internal gear pump (to allow direct comparisons with the resistive control method), a servo motor, a hydraulic accumulator and a directional valve which prevent the flow from de accumulator draining into the reservoir during the downtimes. The controller allows you to establish a direct relationship between the accumulator volume and pressure of the hydraulic circuit. The control methodology discussed throughout this work reveals an alternative volumetric control solution to consider, whether in new equipment or in retrofitting even with the different objectives of existing technologies available in the market. The simulations allow us to conclude on energy-saving and environmental advantages of the volumetric control system presented, comparing it with existing systems on the market.


2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Carlos Zing ◽  
Shadi Mahjoob

Thermal management has a key role in the development of advanced electronic devices to keep the device temperature below a maximum operating temperature. Jet impingement and high conductive porous inserts can provide a high efficiency cooling and temperature control for a variety of applications including electronics cooling. In this work, advanced heat management devices are designed and numerically studied employing single and multijet impingement through porous-filled channels with inclined walls. The base of these porous-filled nonuniform heat exchanging channels will be in contact with the devices to be cooled; as such the base is subject to a high heat flux leaving the devices. The coolant enters the heat exchanging device through single or multijet impingement normal to the base, moves through the porous field and leaves through horizontal exit channels. For numerical modeling, local thermal nonequilibrium model in porous media is employed in which volume averaging over each of the solid and fluid phase results in two energy equations, one for solid phase and one for fluid phase. The cooling performance of more than 30 single and multijet impingement designs are analyzed and compared to achieve advantageous designs with low or uniform base temperature profiles and high thermal effectiveness. The effects of porosity value and employment of 5% titanium dioxide (TiO2) in water in multijet impingement cases are also investigated.


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