Patent Application
20150000643
1. Field of the Invention
This invention is directed to a system designed and structured to fully integrate LNG conversion solution for power plants associated with locomotives, which include, but are not limited to, General Electric AC 4400 and Dash-9 locomotive power plants.
2. Description of the Related Art
Typically locomotives as well as other heavy duty power plants are powered by either direct drive diesel or diesel electric power trains frequently including a multiple horse power turbo charged diesel engine.
Accordingly, it is well recognized that distillate fuels, specifically diesel, are used as the primary fuel source for such power plants. Attempts to maximize the operational efficiency, while maintaining reasonable safety standards, have previously involved modified throttle control facilities. These attempts serve to diminish adverse effects of control mechanisms which may be potentially harmful to the vehicle engine operation as well as being uneconomical. Typical adverse effects include increased fuel consumption and wear on operative components. Therefore, many diesel engines and the vehicles powered thereby are expected to accommodate various types of high capacity payloads and provide maximum power for relatively significant periods of operation. As a result, many diesel engines associated with locomotive are commonly operated at maximum or near maximum capacity resulting in an attempted maximum power delivery from the vehicle engine and consequent high rates of diesel consumption. It is generally recognized that the provision of a substantially rich fuel mixture in the cylinders of a diesel engine is necessary for providing maximum power when required. Such continued high capacity operation of the vehicle engine results not only in wear on the engine components but also in high fuel consumption rates, lower operating efficiencies, more frequent oil changes and higher costs of operation.
Accordingly, there is a long recognized need for a fuel control system specifically intended for use with high capacity, off-road vehicles including mine haul vehicles of the type generally described above that would allow the use of more efficient fueling methods using other commonly available fuel sources. Therefore, an improved fuel control system is proposed which is determinative of an effective and efficient operative fuel mixture comprised of a combination of gaseous and distillate fuels. More specifically, gaseous fuel can comprise natural gas or other appropriate gaseous type fuels, wherein distillate fuel would typically include diesel fuel.
Such a preferred and proposed fuel control system should be capable of regulating the composition of the operative fuel mixture on which the vehicle engine currently operates to include 100% distillate fuel, when the vehicle's operating mode(s) clearly indicate that the combination of gaseous and distillate fuels is not advantageous. Further, such a proposed fuel control system could have an included secondary function to act as a general safety system serving to monitor critical engine fuel system and chassis parameters. As a result, control facilities associated with such a preferred fuel control system should allow for discrete, user defined control and safety set points for various engine, fuel system and chassis parameters with pre-alarm, alarm and fault modes.
The present invention is directed to a system designed as a fully integrated liquid natural gas (LNG) conversion solution for locomotive engines specifically including, but not limited to, the general electric AC 4400 and Dash-9 locomotives.
Moreover, the system of the present invention allows the converted locomotive to operate on a variable mixture of natural gas and diesel fuel will maintaining the performance, reliability and safety of the vehicle. The integrated system utilizes state-of-the-art controls to precisely optimize natural gas fueling rates across the low range of the 7 FDL power unit. In the event of either a system fault or loss natural gas supply, the system and the operating components in characteristics associated there with automatically and seamlessly reverts the locomotive power plant to 100% diesel operation regardless of load condition. Installation of the system of the present invention does not require significant modification of the locomotive engine or auxiliary systems including either the engine governing unit (EGU) or diesel injection system.
The conversion system of the present invention comprises an electronic control unit (ECU) designed to dynamically manage natural gas fueling rates of the engine based on a variety of inputs including RPM, throttle notch position, mass air flow, natural gas flow and alternator power. In addition, the ECU has a power supply that operates using locomotive power ranging from 40-90 VDC and is designed to provide clean power to its internal circuitry that is limited, filtered and transient protected from the vehicle power supply.
The system of the present invention also includes an operator display located in the locomotives operator cab, wherein the system of the present invention is adaptive to other display capabilities.
The system of the present invention also incorporates an integrated air-gas mixer. Low pressure natural gas is applied to the engine using a fumigation method whereby gaseous fuel is admitted upstream of the turbo compressor inlet using a fixed geometry air gas mixing device. Further, the system includes a proprietary mass airflow (MAF) sensor providing combustion air flow data to the ECU. MAF sensor data is utilized for gas mapping and control as well as for engine safety and is used by the ECU to ensure that the air gas mixture supplied to the engine remains below lower flammable limits (LFL).
In addition to the above system incorporates high and low pressure gas controls associated with a complete gas train comprising a manual shutoff valve as well as other operative components. The gas train utilizes and incorporates various pressure and temperature sensors that provide gas pressure and temperature data to the ECU.
In at least one embodiment of the present invention the system includes a comprehensive engine safety system designed to protect against damages relating to dual fuel operation. Also, the system and cooperates an operator safety system designed to protect personnel from hazards associated with the dual fuel operation.
Other structural and operative features of the system of the present invention also include the incorporation of a diesel oxidation catalyst; a fuel measurement system; a telematics sub-system, which may be associated with hardware I/O interface.
In addition to the above, the ECU provides appropriate and predetermined analog inputs; frequency inputs; digital inputs; thermocouple inputs. Operatively associated there with our analog outputs; power drive outputs; discrete outputs, etc. Further, the ECU provides non-volatile memory storage for coding calibration parameters, wherein the memory is sufficient to provide an estimated 70% reserve for future expansion. Further associated with the system it is the provision, by the ECU of operative communication links.
An important function of included power supply circuitry is to monitor the voltage supplied to the digital logic. On power-up, the power supply holds a microcontroller and all outputs in “reset” until the digital logic supply is stabilized and is within tolerances. This technique ensures a pretty microcontroller clocks and memory devices associated with the ECU are functional before the microcontroller starts to execute software.
These and other objects, features and advantages of the present invention will become clearer when the drawings as well as the detailed description are taken into consideration.
For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
Like reference numerals refer to like parts throughout the several views of the drawings.
The present invention is directed to a system (commercially recognized as EVO-LT 4400). Moreover, the system is designed as a fully integrated LNG conversion solution for specific power plants associated with locomotives. The system allows the converted locomotive to operate on a variable mixture of natural gas and diesel fuel while maintaining the performance, reliability and safety of the vehicle.
The system of the present invention incorporates an electronic control unit (ECU) generally represented as 20 in
The ECU has a power supply that operates using locomotive power ranging from 40-90 VDC. It is designed to provide clean power to its internal circuitry that is limited, filtered and transient protected from the vehicle power supply. The ECU power grounds are electrically isolated from its enclosure to meet both safety and EMI design requirements. The ECU design incorporates internal power supplies that provide short circuit protection, thermal limiting, reverse voltage protection and load dump protection of the 200 V. The design also includes the necessary filtering components to minimize emissions, both conducted and radiated.
The system includes an operator display 22 as represented in
As represented in
The system of the present invention includes a complete gas train 28, as represented in
As represented in
In addition to the above, the system includes a vaporizer heating fluid system generally indicated as 40 in
The system of the present invention also includes a diesel oxidation catalyst (DOC) designed as a direct replacement for the existing AC 4400 muffler. The DOC is designed and sized to meet the 10 TPA back pressure requirement. The DOC includes required hardware for installation including gaskets, bolt and ring. The DOC is monitored by the ECU for inlet temperature and inlet/outlet pressure differential. The DOC is designed and sized to reduce expected dual fuel CO emissions by approximately 90% based on the lowest target CO emissions per the notch 8 data. Estimated dual fuel CO emissions are derived using the assumption of 20× tear 0 baseline diesel levels.
The system of the present invention further includes a fuel measurement system that monitors and records real-time consumption of diesel fuel and natural gas. The diesel fuel measurement system utilizes dual flowmeters (inlet and return) in order to calculate net consumption (A−B). The fuel measurement system provides data to the ECU using analog and/or J 1939 inputs. The ECU utilizes diesel fuel and natural gas consumption data for control and safety purposes as well as for data logging in order to track vehicle efficiency and cost savings. The ECU compares natural gas flow rates combustion mass airflow rates to ensure that gas airflow mixture supplied to the powerplant remains below lower flammable limits (LFL).
The system of the present invention further includes telematics system that interface with the ECU and provide remote monitoring capability utilizing commercial cellular networks. With reference to
In addition to the above the ECU provides 32 analog inputs. These are 0-5V or 4 to 20 mA signals capable of being digitized into at least 1024 different levels (10 bit A/D). Inputs have a pull-up down resistor for fault detection along with ESD protection and over/under voltage protection the active range for each input is represented in the following table:
Signals outside the active range will be considered fault conditions. Redundancies provided on gas case pressure inputs.
The ECU will provide for frequency inputs. These are 0-5 V signals operating in the ranges described in the following table. Inputs have a pull-up resistor for fault detection along with ESD dig decoupling and over/under voltage protection.
The allocation of frequency inputs are defined as:
The ECU provides 22 digital inputs. These are 0-72V input signals that have ESD decoupling and over/under voltage protection. The allocation of digital inputs are defined as:
The ECU provides 30 thermocouple inputs. These inputs except type K thermocouples, then amplify and condition the signals appropriately. The inputs have a detection circuit for open conditions. Redundancies provided for the manifold, gas and coolant temperature inputs. The allocation of thermocouple inputs are defined as:
The ECU provides an analog output to the gas throttle body. The output has protection against electrostatic discharge as well as accidental connection to the supply power or ground. This output is dedicated and configured as:
The ECU provides power output (on/off) to control the gas valves and hot fluids pump and to provide power to the throttle body. The outputs have a fly-back protection diode and are protected against electrostatic discharge, as well as accidental connection to supply or ground. They utilized 24V power that is created from the 72V power supply input. Outputs are dedicated and configured as:
The power outputs have internal feedback capabilities that allow for fault detection on the outputs in conjunction with being able to automatically shut off on thermal overload conditions.
The ECU provides two 72V outputs to communicate with the locomotive/tender car 2 spares will also be included for future expansion.
The allocation of discrete outputs are defined as:
The EC provides non-volatile memory storage for coding calibration parameters. Sufficient memory is provided to leave an estimated 70% reserve for future expansion. Paragraph non-volatile memory is provided to store up to 1 GB of blogging. The data logs are critical system parameters per a defined rate, as well as upon the occurrence of any fault elements. Paragraph ECU provides 5 communication links. These links include wired Ethernet for train link; wired Ethernet for operator panel communications; universal serial bus (USB); RS-232 serial port telematics system and J 1939 CAN for knock detection module.
The communications link between the locomotives ECU and the tender cars hot fluids controller utilizes Ethernet converted through a train line converter. This IEEE 802.3 Ethernet port will support 10/100 Mbps speeds and will be transformer coupled.
The operator panel communicates with the locomotive gas control through a 2nd wired ethernet link. The IEEE 802.3 ethernet port supports 10/100 Mbps speeds and is transformer coupled. The USB implementation provides a connection between a USB port in the cab and ECU. The USB port is used for 2 purposes: communicate with a laptop during commissioning and configuration Karen See
Periodic data (2 Second rate) is transferred to the telematics system of the RS 232 serial port. Serial baud rates up to 115.2 K bps are supported. The serial channel has isolation from ECU power supplies.
The knock detection system communicates with the ECU over the CAN serial data link. The ECU provides power for this module. The CAN channel is isolated from the ECU power supplies.
The ruggedized dual fuel locomotive ECU has a power supply that operates from 40-90 VDC locomotive power. It is designed to provide clean power to the ECU internal circuitry that is limited, filtered and transient protected from the vehicle power supply. The ECU power grounds are electrically isolated from its enclosure (chassis ground) to meet both safety and EMI design requirements. The ECU design incorporates internal power supplies that will provide short-circuit protection, thermal limiting, reverse voltage protection, and load dump protection up to 200V. The design also includes the necessary filtering components to minimize emissions, both conducted and radiated. The ECU is designed to be resistant to EMI/EMC, load dump, over-power, and over-temperature conditions.
An important function of the power supply circuitry is to monitor the voltage supplied to the digital logic. On power-up the power supply holds the microcontroller and all outputs in “reset” until the digital logic supplies stabilized and is within tolerances. This technique ensures that the microcontroller clocks and memory devices are functional before the microcontroller starts to execute software. Conversely, the power supply must also learn the microcontroller when it senses that the vehicle battery supply is starting to drop, as occurs when the unit is turned off. The supply warns the microcontroller by issuing a high priority interrupt. When the interrupt is activated, the microcontroller has a fraction of a second to terminate any data rights to memory and to form an orderly shutdown of all outputs. This ensures that all outputs are held in a safe state until “reset” has been completed and the system is returned to normal operating conditions.
The ECU utilizes an automotive-grade 32-bit microcontroller that provides excellent performance over temperature ranges for rugged vehicle applications.
The ECU contains a real-time clock that is utilized to time-stamp the data logging. It has an alternate internal supply to keep the real-time clock operating through unpowered conditions, such as maintenance downtimes.
The PCB uses a mixture of surface mount technology (SMT) and through-hole components, as appropriate. The PCB is designed to protect the electronic components in a shock and vibration environment. Components are securely fastened to the PCB. Surface mount components are used wherever possible. The axial leaded parts are used in place of radial leaded components, as deemed appropriate. The proposed PCB is fabricated from FR4 material.
Is emphasized that while the system of the present invention is primarily described with reference to the bi-fuel (diesel and LNG) operation of a power plant associated with a single locomotive, the system includes structural and operational versatility sufficient to control such bi-fuel operation of more than one locomotive wherein a tender, as described above, may be directly associated with a single locomotive and or more than one locomotive.
Since many modifications, variations and changes in detail can be made to the described preferred embodiment of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents.
Now that the invention has been described,
| Number | Date | Country | |
|---|---|---|---|
| 61830698 | Jun 2013 | US |
