Showing papers on "Prime mover published in 2008"

Technological development in the stirling cycle engines

Abstract: The performance of Stirling engines meets the demands of the efficient use of energy and environmental security and therefore they are the subject of much current interest. Hence, the development and investigation of Stirling engine have come to the attention of many scientific institutes and commercial companies. The Stirling engine is both practically and theoretically a significant device, its practical virtue is simple, reliable and safe which was recognized for a full century following its invention by Robert Stirling in 1816. The engine operates on a closed thermodynamic cycle, which is reversible. Today Stirling cycle-based systems are in commercial use as a heat pump, cryogenic refrigeration and air liquefaction. As a prime mover, Stirling cycles remain the subject of research and development efforts. The objective of this paper is to provide fundamental information and present a detailed review of the past efforts taken for the development of the Stirling cycle engine and techniques used for engine analysis. A number of attempts have been made by researches to build and improve the performance of Stirling engines. It is seen that for successful operation of engine system with good efficiency a careful design of heat exchangers, proper selection of drive mechanism and engine configuration is essential. The study indicates that a Stirling cycle engine working with relatively low temperature with air of helium as working fluid is potentially attractive engines of the future, especially solar-powered low-temperature differential Stirling engines with vertical, double acting, and gamma configuration.

Wound Rotor Induction Generator With Sensorless Control and Integrated Active Filter for Feeding Nonlinear Loads in a Stand-Alone Grid

Abstract: This paper describes a vector control scheme for a stand-alone generator based on a wound rotor induction machine with rotor side control. The stand-alone generator refers to an isolated grid feeding a local load. The primary objective of the control scheme is to maintain constant voltage and frequency at the output of the generator irrespective of prime mover speed variation. A novel, simple, and easily implementable sensorless control scheme is proposed. The issue of power quality, which is one of the main concerns of a stand-alone generation system, is also addressed. This is done by incorporating the active filter concept in the control scheme to cancel significant harmonics. A method of unit vector generation for field-oriented control is proposed. A laboratory prototype consisting of back-to-back insulated-gate bipolar transistor converters and a TMS320F240 DSP controller is developed. Detailed experimental results are presented which demonstrate and validate the effectiveness of the proposed scheme.

Hybrid vehicle drive system and method and idle reduction system and method

Abstract: One embodiment relates to a hybrid vehicle drive system for a vehicle including a first prime mover, a first prime mover driven transmission, a rechargeable power source, and a PTO. The hybrid vehicle drive system further includes a hydraulic motor in direct or indirect mechanical communication with the PTO and an electric motor in direct or indirect mechanical communication with the hydraulic motor. The electric motor can provide power to the prime mover driven transmission and receive power from the prime mover driven transmission through the PTO. The hydraulic motor can provide power to the prime mover driven transmission and receive power from the prime mover driven transmission through the PTO.

Current source converter-based wind energy system

Abstract: Power conversion apparatus and methods are presented for providing electrical power to a grid or other load in which a synchronous machine is driven by a wind turbine or other prime mover to provide generator power to a switching type current source converter (CSC), with a current source rectifier (CSR) of the CSC being switched to provide d-axis control of the synchronous machine current based on grid power factor feedback, and with a current source inverter (CSI) of the CSC being switched to provide leading firing angle control and selective employment of dumping resists to dissipate excess generator energy in a fault mode when a grid voltage drops below a predetermined level.

Systems and methods for control of transmission and/or prime mover

Abstract: Disclosed here are inventive systems and methods for a powertrain of an electric vehicle (EV). In some embodiments, said powertrain includes a continuously variable transmission (CVT) coupled to an electric drive motor, wherein a control system is configured to control the CVT and/or the drive motor to optimize various efficiencies associated with the EV and/or its subsystems. In one specific embodiment, the control system is configured to operate the EV in an economy mode. Operating in said mode, the control system simultaneously manages the CVT and the drive motor to optimize the range of the EV. The control system can be configured to manage the current provided to the drive motor, as well as adjust a transmission speed ratio of the CVT. Other modes of operation are also disclosed. The control system can be configured to manage the power to the drive motor and adjust the transmission speed ratio of the CVT taking into account battery voltage, throttle position, and transmission speed ratio, for example.

Method and system for the small-scale production of liquified natural gas (lng) from low-pressure gas

Abstract: A method and system for the small-scale production of LNG. The method comprising: configuring a prime mover to be operable communication with a multi-stage compressor; configuring the prime mover to be in fluid communication with an ammonia absorption chiller; configuring the ammonia absorption chiller to be in fluid communication with the multi-stage compressor; operating the ammonia absorption chiller using waste heat from a prime mover; pre-cooling a first stream of natural gas using cooled fluid from the ammonia absorption chiller; cooling a first portion of the first stream of natural gas, using an expansion valve, into a two-phase stream; cooling a second portion of the first stream to liquefied natural gas, using the two-phase stream as a cooling fluid; delivering the second portion of the first stream as LNG to a low-pressure LNG tank; cooling a third portion of the first stream of natural gas in a turbo-expander; separating liquid heavies out of the third portion of the first stream of natural gas; and delivering the liquid heavies to a pressure tank.

Hybrid powertrain and dual clutch transmission

Abstract: An automatic dual clutch transmission includes an input clutch which selectively connects a prime mover to an electric motor. The electric motor output, in turn, drives a pair of gears, one of which is in constant mesh with a first gear on a first quill and a second gear on a second quill, the other being in constant mesh with a third gear on the first quill and a fourth gear on the second quill. On each quill, between each pair of gears driven by the input is a pair of dog clutches which connect one of the two gears to the associated quill. Each of the quills drives an input of a respective pair of friction clutches which drive a respective pair of layshafts or countershafts. A similar arrangement of a second pair of gears flanked by dog clutches connects each layshaft or countershaft through one of a pair of gears which are in constant mesh with a pair of output gears coupled to and driving a differential cage.

Air conditioning system

Abstract: PROBLEM TO BE SOLVED: To provide an air conditioning system, securing starting of a prime mover of an outdoor unit without receiving power from a commercial power supply. SOLUTION: An outdoor unit 1 drives a compressor 11 and a power generator 12 by a prime mover 10 using gas fuel or liquid fuel. An indoor unit 2 constitutes a heat pump with the compressor 11. The power generator 12 charges a secondary battery 41 of a capacitor 4 provided separately from the outdoor unit 1, and the power of the capacitor 4 is used for starting the prime mover 10 provided in the outdoor unit 1. Each outdoor unit 1 includes a clutch provided between the prime mover 10 and the compressor 11 to select connection or separation. The capacitor 4 includes a capacity monitoring part 42 for monitoring the residual capacity and a charging designating part 43 for requesting the outdoor unit 1 in the process of stopping to operate when the residual capacity amounts to a regulated threshold or less, and selecting separation of the clutch to designate that only the power generator 12 is operated singly by the prime mover 10. COPYRIGHT: (C)2009,JPO&INPIT

Effect of Inner Diameter Change of Phase Adjuster on Heat-to-Sound Energy Conversion Efficiency in Loop-Tube-Type Thermoacoustic Prime Mover

Abstract: The use of a phase adjuster (PA) has been proposed to improve the cooling effect of a loop-tube-type thermoacoustic cooling system. A PA is a device for increasing the particle velocity of sound by narrowing a part of the loop tube. In this experiment, we present a discussion of the efficiency of heat-to-sound energy conversion in a loop-tube-type thermoacoustic prime mover, particularly emphasizing on the inner diameter change of PA. It is found that the sound pressure is higher for larger inner diameter; the particle velocity is higher for larger inner diameter and the phase difference between the sound pressure and the particle velocity is bigger for larger inner diameter. It is also found that sound intensity is different according to the inner diameter, and that it is higher for larger inner diameter. Results obtained confirm that PA improves the efficiency of heat-to-sound energy conversion in the loop-tube-type thermoacoustic prime mover, and that the efficiency depends on the inner diameter of PA.

Air-conditioning and electric power generating system and control method for the same

Abstract: An air-conditioning and electric power generating system (1) including a gas heat pump type air conditioner, an electric power generator (11) that is driven by a gas engine (10) and has electric power generating capacity corresponding to the driving power of the gas engine when a compressor (12) is separated from the gas engine (10) by a clutch (14), a system interconnection type inverter (33) that is connected to the electric power generator (11) and outputs power to a commercial system (35), a waste heat using portion (29) for using waste heat of the gas engine (10), and an engine controller having a first control mode and a second control mode as a driving mode to control the driving of the gas engine. The engine controller (51) controls the gas engine to serve as a gas engine for driving both the compressor and the electric power generator in the first control mode while controlling the gas engine to serve as a gas engine for driving only the electric power generator in the second control mode.

Robust design evolution and impact of In-Cylinder Pressure Sensors to combustion control and optimization : a systems and strategy perspective

Abstract: In-Cylinder Pressure Sensors (ICPS) today are close to satisfying the robustness, performance and cost requirements for application to closed loop control and monitoring of production automotive engines. Using the Robust Design framework as a compass, this thesis first checks the evidence for emergence followed by tracking the evolution of the sensor component itself and its application to robust closed loop control of the combustion process in internal combustion engines. After identifying the potential system level impact of the emerging ICPS technology, System Dynamic and Technology Strategy frameworks are used to find spillover triggers and to recommend a number of strategic options to generate and capture value for integrated system solution providers so that they can beat the very stable status quo that persists in the slow and mature prime mover industries. In addition, Chapter 2 gives a data driven method for identifying the Skills needed for suppliers to realize the above recommendations. This method is based on collective intelligence of 690 experienced professionals with 20 years of work experience on average from 40 targeted companies, representing a large body of engineering and managerial experience in battling complex engineering system hurdles. This approach is more effective than blindly copying the prominent integrated system solution providers or OEM’s, because a side effect of long term incremental innovation in the mature prime mover industry is that the underlying reasons for their success is ingrained in their ”tacit knowledge” and ”organizational furniture” and hence not explicitly understood. Thesis Supervisor: Dan Frey Title: Professor of Mechanical Engineering and Engineering Systems, MIT Thesis Supervisor: Michael A. M. Davies Title: Professor of Technology Strategy, MIT

Marine vessel energy system

Abstract: PROBLEM TO BE SOLVED: To decrease fuel used in a prime mover for an auxiliary machine thereby to reduce exhaust gas by operating in an efficient region the prime mover for the auxiliary machine which drives auxiliary machine generators when a marine vessel enters a port and reaches the shore. SOLUTION: A marine vessel energy system includes: a power detection means 20 for detecting power consumed by an electric propulsion device 200a; a charging/discharging power storage device 21 connected to an in-vessel power bus 6; a starting switch 12 for giving a start command to a bow thruster 300; and a control circuit 22 which changes the power storage device into a charge mode when a detection signal of the power detection means becomes a threshold value or below, and changes it into a discharge mode upon the start command of the starting switch and discharges the stored power to the in-vessel power bus. When propulsion is carried out by decreasing the propulsion force of the electric propulsion device during entering the port and the power consumption thereof becomes a threshold value or below, the power storage device is charged from the auxiliary machine generators 4-1 and 4-2 by the control circuit. If the start command of the starting switch is received during the charging operation, the power storage device is operated to discharge, and the discharged power is supplied to the bow thruster. COPYRIGHT: (C)2010,JPO&INPIT

Acceleration shock reduction apparatus for vehicle

Abstract: A vehicle control system includes a prime mover, a power transmission apparatus disposed between the prime mover and at least one wheel, an engaging element configured to selectively engage and disengage the prime mover from the at least one wheel, and a torque limiter configured to restrict an output torque of the prime mover to a selected percentage when in transition between an unloaded state and a loaded state, wherein the torque limiter is configured to restrict the output torque of the prime mover while the engaging element is disengaged between the prime mover and the power transmission apparatus.

Transmission and transportation equipment equipped with power transmission unit using transmission

Abstract: PROBLEM TO BE SOLVED: To provide a transmission for transmitting a driving force of all transportation equipment of a prime mover type or non-prime mover type such as a two-wheel to four-wheel cycle and vehicle, and a cycle equipped with a power transmission unit using the transmission. SOLUTION: Driving force is related to a fine speed changer of a differential reduction gear system, a rough speed changer of an inner contact reduction gear system and an output section of an intersecting axle power transmission system, arbitrarily and selectively by a chain-less method by using a shift lever, to finely change speed multi-stepwise in each of rough speed change stages for low/high speed. COPYRIGHT: (C)2009,JPO&INPIT

Single stage starter/generator with rotor quadrature AC excitation

Abstract: When driven by a variable speed prime mover, a generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to and located in a common core as the main rotor windings to provide two-phase excitation current to the main rotor windings. The exciter stator winding is also located in a common core as the main generator stator windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed and rotor position of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required.

Power transmission unit for vehicle

Abstract: A power transmission unit including: a first prime mover; speed change gear pairs; output members; a differential mechanism, which has a first rotary element connected with the first prime mover, a second rotary element, and a third rotary element selectively outputting the power to the output member, and adapted to perform a differential action among those three rotary elements; and a second prime mover connected with the second rotary element. The speed change gear pair includes at least one pair of first speed change gear pair, arranged between the first rotary element and the output member and allowed to transmit the torque selectively, and at least one pair of second speed change gear pair arranged between the third rotary element and the output member and allowed to transmit the torque selectively. A locking mechanism locks the second prime mover selectively to halt a rotation of the second prime mover.

A Survey of Cassava Processing Machinery in Oyo State

Abstract: Survey of cassava processing machinery was carried out to evaluate the followings: different cassava processing machinery, the most acceptable machine, effect of cost of machinery on the processors and to determine whether sex of machine operator is dependent on the type of prime mover in Oyo State, Nigeria. This information was gathered using structured questionnaires, which was designed and administered between March 2003-May 2003. A total of 212 machines were observed, grating, 79 (37.6%) dewatering press, 61 (28.8%), chipping, 8 (3.8%), sifter 7 (3.3%), fryer, 1 (0.5%), milling, 51 (24.1%). Diesel engine (80.4%) was the most prominent prime mover. Greater numbers of processing centres were owned by individual. The relationship between the processors and the machines manufacturers was poor. More than 40% of the machines observed had been abandoned and these could be attributed to adulterated spare parts, operation cost, inexperience machine repairers, untrained machine operators and quality of the construction materials. The sex of the machine operators was dependent on the type of prime mover. Diesel engines were operated majority by males while petrol engines were mostly operated by females. The detailed analyses of the observed cassava processing machines were discussed and recommendations were made based on the finds of this study.

Working-vehicle transmission system

Abstract: A working vehicle transmission system comprises a PTO device for driving an external working device by power of a prime mover, and a multistage transmission for transmitting power from the prime mover to an axle. The multistage transmission includes a main speed-change mechanism and a sub speed-change mechanism. The main speed-change mechanism has plural drive trains for setting respective different speed stages. The sub speed-change mechanism is disposed downstream of the main speed-change mechanism and has plural drive trains for setting respective different speed stages. The main speed-change mechanism includes a first clutch and a second clutch. The main speed-change mechanism drive trains used for setting odd-numbered speed stages are activated by engaging the first clutch. On the other hand, the main speed-change mechanism drive trains used for setting even-numbered speed stages are activated by engaging the second clutch. During a speed-change operation of the main speed-change mechanism, an engagement action of one of the first and second clutches and a disengagement action of the other of the first and second clutches overlap each other. A reverser is disposed upstream of the first and second clutches of the main speed-change mechanism so as to enable switching the direction of output rotation transmitted to the first and second clutches from one direction to the opposite direction.

Reduction in Temperature Difference of Prime Mover Stack in Loop-Tube-Type Thermoacoustic Cooling System by Applying Phase Adjuster

Abstract: The use of a phase adjuster (PA) is proposed to reduce the temperature difference between the upper and lower ends of the prime mover stack in a loop-tube-type thermoacoustic cooling system. PA is a device for increasing particle velocity. By placing PA in the loop tube, the resonance is forcibly one wavelength. It is confirmed that the temperature difference of the prime mover stack with PA is smaller than that without PA. Because PA prevents the resonance wavelength shift from one-wavelength resonance to two-wavelength resonance, the loop tube suppresses the increase in temperature at the prime mover stack, so that the viscous boundary layer thickness is smaller than the stack channel radius. This induces an effective energy conversion. Consequently, the temperature difference is reduced.

Motor vehicle energy converter

Abstract: An energy conversion apparatus using recovered energy sources including motor vehicle kinetic energy and wind resistance, supplemented by liquefied air transferred to the vehicle and by solar radiation thereto. The energy sources are combined, as available, to drive a compressor for supplying intake working fluid of a motor vehicle prime mover.

Pump torque control system for hydraulic construction machine

Abstract: A pump torque control system is capable of preventing hunting due to interference between speed sensing control and control of an engine speed of a prime mover when the temperature of a hydraulic fluid is low A maximum absorption torque is set in a regulator 31 that controls displacement volumes of hydraulic pumps 2 and 3 based on a deviation between target and actual engine speeds of a prime mover 1 A second modification factor calculating section 45 and a control gain modifying section 49 , which are included in a controller 23 that performs speed sensing control to ensure that the maximum absorption torque of the hydraulic pumps 2 and 3 is reduced, change a control gain of the speed sensing control based on a value detected by the hydraulic temperature sensor 34 to ensure that the control gain is reduced as the temperature of the hydraulic fluid is reduced

More electric engine with regulated permanent magnet machines

Abstract: A generator and associated power supply system (20) comprises a prime mover (22) for driving a shaft (24) to rotate. A pair of permanent magnets (26,28) is associated with the rotating shaft. A first stator winding (30) is associated with a first (26) of said permanent magnets, and supplies a customer DC bus (38) for providing a first relatively low voltage to the customer DC bus. A second (28) of said permanent magnets is associated with a second stator winding (54), and an engine accessory DC bus (58). The engine accessory DC bus provides power to a motor controller (60) and associated accessory motors (62,64,66) associated with the prime mover. The engine accessory DC bus is provided with a second relatively high voltage from the second stator winding.

Dynamic performance analysis of a hybrid wind turbine generator system

Abstract: The dynamic performances of a hybrid wind turbine generator system using a shaft generator system are investigated. The hybrid system consists of a wind turbine and generator, a rectifier, a current-source thyristor inverter, a synchronous generator driven by a prime mover and a duplex reactor. The configuration of the hybrid wind turbine generator system is explained first, and a dynamic model of the hybrid system is developed. The dynamic performances of the system when the wind velocity is changed are then discussed. Finally, a control system to keep the output voltage and power of the whole system constant is introduced, and it is shown that these outputs can be controlled almost constant independent of wind velocity.

Vehicular power transmission system

Abstract: To provide a power transmission unit, which is capable of reducing a power loss, and which is downsized to be mounted on a vehicle easily. A power transmission unit according to the present invention comprising: a first prime mover 2; speed change gear pairs 14 to 17; output members 11 and 12; a differential mechanism 1, which has a first rotary element Cr connected with the first prime mover 2, a second rotary element Rg, and a third rotary element Sn selectively outputting the power to the output member, and which is adapted to perform a differential action among those three rotary elements; and a second prime mover 3 connected with the second rotary element; wherein the speed change gear pair includes at lease one pair of first speed change gear pair, which is arranged between the first rotary element and the output member and which is allowed to transmit the torque selectively, and at least one pair of second speed change gear pair which is arranged between the third rotary element and the output member and which is allowed to transmit the torque selectively; and a locking mechanism SL for locking the second prime mover selectively to halt a rotation of the second prime mover.