Title of Invention

A TWINPOINT HYDROGEN GAS INJECTION SYSTEM FOR SINGLE FUEL

Abstract

This invention relates to multipoint gas injection system comprising, a common gas plenum assembly having a gas rail with outlets and a low pressure sensor, plurality of injectors, said injectors connected to the outlets of said gas rail, at least one cylinder, an air intake plenum, a runner pipe connected between said intake plenum and said cylinder, and two said injectors located in said runner pipe to inject gas into runner pipe.

Full Text

FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF INVENTION Multipoint Sequential Gas Injection System APPLICANTS TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India INVENTORS Jaygopal S and Arunendra Mishra both Indian nationals of TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION This invention relates to automotive engine technology and more particularly to multi point electronic fuel injection system. Gaseous fuels such as HYDROGEN or Compressed Natural Gas (CNG) are injected in individual intake ports of internal combustion engine by metering the fuel amount. BACKGROUND OF INVENTION Recently, the importance has been placed on the cleanliness of exhaust gas by reducing the pollutants like CO2, CO _ NOx and HC. There are limitations to meet these requirements using Fossil Fuels in conventional IC engines. So, past decades have seen an increased demand for use of gaseous fuel as a fuel source in both compression and spark ignition engines. Gaseous fuels combustion engines that burn natural gas, petroleum gas, and hydrogen gas produces less emission from tail pipe. Hydrogen is the promising fuel to meet energy sustainability and no Green House Gas emissions. Day-by-day the fossil fuel price is increasing and the day is going to come when the cost of hydrogen will be comparable with conventional (Gasoline / Diesel) fuels along with development of hydrogen technologies. To meet the IC engine requirement for Hydrogen Fueling system, a technological need has arisen for safe and precise fuelling system. As the Hydrogen fuel needs to be handled through Electronically Controlled Unit, the fuelling system is to be a dedicated Multipoint Hydrogen Injection system. The existing fueling system for gaseous fuel like CNG has one mixture unit, which is mixing CNG & Air at desired A/F ratio. This mixture unit works like carburetion system. The amount of fuel (CNG) depends upon the vacuum generated at intake manifold during suction. This closed-loop system can work only for Stoichiomatric (X- 1) operation. This system is not suitable for hydrogen application as it needs Lean-Burn & Leak-Proof and better control on fuelling. Throttle Body Injection system can be a better option than Air-Valve Mixture type for Hydrogen application, but TBI will result into back-fire in Multi-Cylinder engines. So, to overcome these problems the better option will be Multi-point Sequential Hydrogen Gas Injection. In Patent No. US 5,713,336, single injector per cylinder is used for gas fuel injection technique in IC engine. But this single injector may not be suitable for higher capacity engine cylinders, to meet fuel required per cylinder per cycle, particularly fuel like hydrogen. Because, hydrogen has got very low density (energy density as well) and higher diffusivity. Hence this invention is very much suitable even for higher capacity multi-cylinder IC Engines to meet the required flow-rate and precise timing. So, the prime objective of this invention is to provide sufficient amount of fuel delivered per cylinder to get desired engine power out put. Most of the researchers studied and published the hydrogen fuel induction methods for Single Cylinder IC engine. Among them L M Das (Int. J hydrogen energy 1990), has conducted different experiments on fuel induction technique for hydrogen operated engine to recommend an optimum fuelling technique. His attempts were made to run the engine with four different methods such as Carburetion, Continuous Manifold Injection (CMI), Timed Manifold Injection (TMI) and Direct In-cylinder Injection. Chasten et al (Patent No. US005,343,847A) has filed a patent for electronic gaseous fuel injection system where a gaseous fuel delivery system for an internal combustion engine having at least one cylinder with fuel intake and exhaust gas port. A fuel flow control device connected between the source of gaseous fuel and fuel plenum which contains an electronic control unit having a plurality of optimum Fuel/Air mixture variable as inputs and a modulated pulse width output connected to DC motor, the stroke of which controls the operation of a fuel valve for regulating the of fuel from the gaseous source to the fuel plenum. This control system seams to be an Electronically Controlled Fuel metering device and may not be suitable for sequential injection (Hydrogen Fuel). A multi-point fuel injection (liquid / gasoline fuel) system is extensively employed for gasoline automotive engine application to improve fuel economy and reduced emission with higher power. Multipoint fuel injection of gaseous fuel is highly attractive method of metering fuel. Multipoint fuel injection permits much more precise control of fuel flow than single point or carburetion type fueling system. SUMMARY OF INVENTION This invention is about the design of components, which are being recommended for Multi Point gas Injection system in a dedicated (100 %) hydrogen IC engine. The invention has the capability to provide the accurate fuel control for all load condition. Further, the objective of this invention is to ensure leak-proof design of fueling system and safe running of multi-cylinder engine without back-fire. Unlike conventional multi point fuel injection system, the design of present invention system utilizes two injectors per cylinder & connected to a common fuel plenum / rail for multi-cylinder engine. These injectors are connected through flexible pipe to Common Rail, and the rail receives fuel from electronically controlled low-pressure regulator. This invention needs very minimal hardware modification to convert conventional Diesel engine to Hydrogen IC engine. Further this Multipoint Hydrogen Injection system provides precise control of fuel injection timing and the duration with better drivability and safe vehicle running. There are other needs exist for a multipoint gaseous fuel injection system that may be used to provide fuel to virtually any type of internal combustion engine and it should be compatible with all types of gaseous fuels. Hence this system will be suitable. According to present invention a multipoint gas injection system comprising, a common gas plenum assembly having a gas rail with outlets and a low pressure sensor, plurality of injectors, said injectors connected to the outlets of said gas rail, at least one cylinder, an air intake plenum, a runner pipe connected between said intake plenum and said cylinder, and two said injectors located in said runner pipe to inject gas into runner pipe. BRIEF DESCRIPTION OF DRAWINGS For complete understanding of this invention a preferred exemplary embodiment of the invention is illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout, and in which: FIG . 1 shows schematic diagram of IC Engine, Hydrogen Storage & Supply System, ECU and Interfacings. FIG. 2 shows common Rail and Injectors arrangement Fig. 3 shows the injection system according to present invention. DETAILED DESCRIPTION OF INVENTION Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same. Referring to the figures, the Internal Combustion Engine comprising multi cylinders, Pistons, 2 valves per cylinder, Ignition Coils, Cylinder block, Cylinder Head, Cam shaft, Push-Rod, Plenum chamber, Fuel Rail, Hydrogen Injectors(2 per cylinder), Crankshaft, Accessories Drives and etc. Hydrogen gas is stored in Composite cylinders (10). These cylinders consist inbuilt High-Pressure Regulator (11). High pressure line (13) carries hydrogen gases to electronics Low-Pressure Regulator (14), which converts high pressure to working level pressure. Electronically controlled low-pressure line (15) carries hydrogen gases to common rail (16). Electronically controlled low pressure regulator which in turn connected to fuel storage through higher pressure regulator and a solenoid gas shutoff valve. The common rail assembly consist a low pressure sensor (31) to monitor the rail-pressure. Flexible metal pipes (26, 17) carry Hydrogen gas to hydrogen injector (44). Intake manifold (19) consists of plenum chamber (30), Temperature and manifold absolute pressure (TMAP) Sensor (24) and Electronically Controlled Throttle body (23). In the intake port (22), the Air is delivered to cylinder through intake valves, the valve Opening & Closing controlled by a cam shaft ( not shown). Upper slot (25) and side slot (27) are provided on intake runner pipe (22) to accommodate twin injectors and ensuring the optimized angle of injection with respect to air flow direction. The exhaust port (21) is provided with exhaust valve, the valve opening and closing controlled by a cam. As shown in figure 2, this system embodiment is used in an internal combustion engine. The engine cylinder (36) is communicated with intake runner (22) and exhaust port (not shown in figure) for air and fuel in-flow and burned gas out-flow respectively. An intake valve (35) is provided between intake port and in cylinder space (36) of internal combustion engine. Common rail (16) is mounted on top of plenum chamber (30). Two injectors (44 & 49) are assembled on intake runner (22). Top injector (49) and side injector (44) are placed perpendicular to each other in intake runner. Injection of Hydrogen gas (fuel) into the intake runner at position ensures the Homogenous mixing of Fuel & Air for complete combustion. By providing two injectors per cylinder, Fuel (low density hydrogen) required per cycle per cylinder (high cubic capacity) can be met at higher engine power output. FIGURE 3 shows the Multi-Point Hydrogen Injection system. The Hydrogen gas flows from Common rail plenum (40) to hydrogen injectors (44) through flexible pipes (17,26). These injectors (44, 49) are controlled by ECU (18) for safe opening & closing in sequential w.r.t firing order. The intake runner pipe (length is tuned for Ram Effect) (22) is in fluid communication with plenum (30), it delivers air to individual cylinder inline with intake valve timing. Air-flow rate to the plenum has been controlled by an Electronically Controlled Throttle-body (23) as shown in figure 1, which is assembled at upper stream of intake (plenum). In conventional fuel injection system, single fuel injector is positioned at intake port, however in this invention twin electronically control hydrogen gas injectors are placed in intake runner pipe close to intake port. Injectors are placed perpendicular to each other so that the gas is injected inside the runner pipe substantially perpendicular to each other. Injectors are located in slots provided on the runner pipe. The slots are substantially perpendicular to each other. The injectors are disposed in the slots provided on the runner pipe in a leak proof manner. Basic concern for twin type injectors is to meet the required amount of hydrogen flow-rate per cylinder within available time during intake stroke. To withstand vibration and to accommodate injectors on runner pipe, the new assembly (45) has been designed and adopted in the system. This assembly (45) provides leak proof arrangement for MpHi. The twin injector assembly unit (45) comprises a housing, which horizontally divided in upper and lower plate. These two injectors are assembled in single unit and inject the fuel in the adjacent cylinder ports. The complete assembly (Fuel Rail, Injector Assembly, Flexible pipe) has been assembled on intake system through two brackets (48). The volume of Common Rail pipe is decided by considering rail as fuel plenum chamber. The constant rail pressure is maintained through out the engine operation and the low-pressure sensor is used to ensure the leak-proof hydrogen flow for safer usage. Low-pressure electronically controlled pressure-regulator (14) keeps the rail pressure constant. One end of the rail (30) is connected to hydrogen inlet from storage and the other part is connected with a low-pressure (31) sensor. In this assembly the flexible metal pipes (42) connected between fuel rail and injector, in such a way to meet the vibration test and leak-proof joints (special joints) (41) with higher reliability. The common rail plenum assembly and fluid lines are made of stainless steel. The advantage of using two injectors is, it avoids the back-fire issues by optimizing the injection timings in the latter period of intake stroke. This is ensured by initial entry of pure air into the cylinder through intake port, cools the engine cylinder, combustion chamber, the exhaust & inlet valves and crevice volume. Hence there is no hot spot to initiate any unwanted combustion. By providing two injectors per cylinder, Fuel (low density hydrogen) required per cycle per cylinder (high cubic capacity) can be met at higher engine power output. The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof. WE CLAIM 1. A multipoint gas injection system comprising, a common gas plenum assembly having a gas rail with outlets and a low pressure sensor, plurality of injectors, said injectors connected to the outlets of said gas rail, at least one cylinder, an air intake plenum, a runner pipe connected between said intake plenum and said cylinder, and two said injectors located in said runner pipe to inject gas into runner pipe. 2. The multipoint gas injection system as claimed in claim 1, wherein injectors located in said runner pipe are perpendicular to each other. 3. The multipoint gas injection system as claimed in claims 1 and 2, wherein said gas rail connected to an electronically controlled low pressure regulator which is in turn connected to fuel storage through higher pressure regulator and a solenoid gas shutoff valve. 4. The multipoint gas injection system as claimed in claims 1 to 3, wherein a constant pressure is maintained from low pressure regulator to injector. 5. The multipoint gas injection system as claimed in claim 1 wherein said common gas plenum assembly made of stainless steel. 6. The multipoint gas injection system as claimed in claims 1 and 3, wherein said gas rail outlets connected to injectors through flexible metal pipes. 7. The multipoint gas injection system as claimed in claims 1 and 2, wherein said injectors are electronically controlled. 8. The multipoint gas injection system as claimed in claims 1, 2 and 7, wherein said runner pipe having two slots perpendicular to each other to accommodate said injectors. 9. The multipoint gas injection system as claimed in claim 8, wherein said injectors are disposed in said slots in a leak proof manner to inject gas inside said runner pipe in perpendicular to each other. 10. The multipoint gas injection system substantially as herein described with reference to accompanying drawings. ABSTRACT Multipoint Sequential Gas Injection System Figure 3 This invention relates to a multipoint gas injection system comprising, a common gas plenum assembly having a gas rail with outlets and a low pressure sensor, plurality of injectors, said injectors connected to the outlets of said gas rail, at least one cylinder, an air intake plenum, a runner pipe connected between said intake plenum and said cylinder, and two said injectors located in said runner pipe to inject gas into runner pipe.

Documents:

688-MUM-2008-ABSTRACT(26-5-2014).pdf

688-mum-2008-abstract.doc

688-mum-2008-abstract.pdf

688-MUM-2008-CLAIMS(AMENDED)-(19-10-2012).pdf

688-MUM-2008-CLAIMS(AMENDED)-(26-5-2014).pdf

688-mum-2008-claims.doc

688-mum-2008-claims.pdf

688-mum-2008-correspondence(24-4-2008).pdf

688-mum-2008-correspondence-received.pdf

688-mum-2008-description (complete).pdf

688-MUM-2008-DRAWING(19-10-2012).pdf

688-MUM-2008-DRAWING(26-5-2014).pdf

688-mum-2008-drawings.pdf

688-MUM-2008-FORM 1(26-5-2014).pdf

688-mum-2008-form 18(24-4-2008).pdf

688-MUM-2008-FORM 2(TITLE PAGE)-(26-5-2014).pdf

688-mum-2008-form 2(title page)-(28-3-2008).pdf

688-MUM-2008-FORM 3(26-5-2014).pdf

688-mum-2008-form 8(24-4-2008).pdf

688-mum-2008-form 9(24-4-2008).pdf

688-mum-2008-form-1.pdf

688-mum-2008-form-2.doc

688-mum-2008-form-2.pdf

688-mum-2008-form-3.pdf

688-MUM-2008-GENERAL POWER OF ATTORNEY(26-5-2014).pdf

688-mum-2008-general power of attorney(28-3-2008).pdf

688-MUM-2008-MARKED COPY(19-10-2012).pdf

688-MUM-2008-MARKED COPY(26-5-2014).pdf

688-MUM-2008-REPLY TO EXAMINATION REPORT(19-10-2012).pdf

688-MUM-2008-REPLY TO HEARING(26-5-2014).pdf

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