DESC:TECHNICAL FIELD
[0001] The present invention generally relates to an internal combustion engine of an automobile. More particularly, the present invention relates to a system for starting the internal combustion engine employing gaseous fuels.

BACKGROUND
[0002] An internal combustion engine converts thermal energy obtained from burning of a fuel with an oxidizer (air) into mechanical energy, which can be used to do some kind of mechanical work. It is used in a wide range of applications including providing motive force for movement of an automobile. Internal combustion engine fuelled by gaseous fuels is now gaining importance during recent times as it offers a lot advantages over conventional liquid fuels such as availability at lower cost, lesser emissions, higher octane rating, lesser carbon build-up in spark plugs, lesser oil changes, and lesser corrosion and engine wear. At the same time, they provide comparable power, acceleration and payload as that of an equivalent automobile fuelled by conventional liquid fuels. Additionally, these gaseous fuels can be used for the same internal combustion engines conventionally fuelled by liquid fuels without changing the engine design. Some of the common gaseous fuels employed include compressed natural gas (CNG) and liquefied petroleum gas (LPG). CNG is made by compressing natural gas (primarily composed of methane), to less than 1% of its volume at standard atmospheric pressure. LPG is a mixture of propane and butane obtained from refining crude natural gas. LPG liquefies under pressure and stored in pressurised containers. In the internal combustion engine employing gaseous fuels, the air fuel mixture ratio is critical as, in certain operating conditions results in poor startability. Hence, it is desirable to provide a system and a method to ensure good startability of the internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWINGS
[0001] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[0002] Fig. 1 illustrates the system block diagram of a system for starting an internal combustion engine according to the embodiment of the present invention.
[0003] Fig. 2 illustrates the method flowchart of the system for starting an internal combustion engine according to the embodiment of the present invention.
DETAILED DESCRIPTION
[0004] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. The detailed explanation of the constitution of parts other than the present invention which constitutes an essential part has been omitted at suitable places.
[0005] Automobiles employing gaseous fuels are considered a better alternative as compared to conventional liquid fuels because of many benefits. It can be used in the same conventional internal combustion engine that is using the liquid fuels. Hence, air and gaseous fuel mixture is also made to enter the internal combustion engine, compressed by a reciprocating piston and ignited by spark ignition. Conventionally, all automobiles which operate on gaseous fuels also operate on conventional liquid fuels thus having dual mode.
[0006] Fuel supply systems play a major role in analyzing startability characteristics of the internal combustion engine fuelled by gaseous fuels. In this regard, there are mainly two types of fuel systems employed, carburetor fuel supply and electronic fuel injection supply. Carburetor fuel supply system relies on mechanical devices to supply air fuel mixture to the internal combustion engine.
[0007] In internal combustion engines having carburetor fuel supply system, there are problems of startability, and the internal combustion engine can fail to start in many operating conditions. This can be attributed to many reasons, the primary reason being, under these operating conditions the optimum air-fuel ratio of the resulting air fuel mixture is not obtained. Generally, gaseous fuels for example compressed natural gas (CNG), which consists of primarily methane the scope of the ignitable mixture ratio is narrow and the optimum air-fuel ratio for combustion in the internal combustion engine is in a narrow range of 0.9 to 1.1. This means that, air-fuel ratio must be in the narrow range of 0.9 to 1.1, or else the air fuel mixture will not combust inside the internal combustion engine. If the air-fuel ratio is greater than 1.1 it becomes a too lean mixture and if the air-fuel ratio is below 0.9 it becomes a very rich mixture. Hence, for optimum combustion of gaseous fuel and air mixture in the internal combustion engine, it is necessary to form the air-fuel mixture of reliably ignitable ratio. But, in many operating conditions, achieving such air-fuel ratios is not possible due to variety of reasons. But, during normal operating condition of the internal combustion engine, due to engine heat and better engine suction capability optimum air-fuel ratio is always obtained and the internal combustion engine performance characteristics is equivalent to that of conventional liquid fuels. Additionally, gaseous fuels have highest minimum ignition energy; hence more work is required to combust gaseous fuels compared to other conventional fuels. Some operating conditions hinder the combustion of gaseous fuels which is already operating at such a minimum ignition energy.
[0008] The operating conditions when can affect air-fuel ratio include, cold atmospheric conditions, hot atmospheric conditions, higher attitude conditions, lesser battery voltage and clogged/ choked air induction system. In cold atmospheric conditions, such as during night or in cold locations with ambient temperature below 20 degrees, the density of air is high, hence for the same fuel flow to the carburetor, air flow is higher. This provides a lean air fuel mixture to the internal combustion engine, and such lean air-fuel ratio may be beyond the limit set for gaseous fuels (in the range 0.9 to 1.1). Additionally, frictional losses in the internal combustion engine are high and hence flame quenching takes place due to colder cylinder walls. Poor startability can also be observed in hot conditions such as in summer season or in hot locations such as deserts where the ambient temperatures are above 45 degrees. Here, the air density outside is less, hence for the same fuel flow to the carburetor, less air flow is obtained at the carburetor, hence there is a rich air fuel mixture. This provides a rich air fuel mixture to the internal combustion engine, and such rich air-fuel ratio maybe beyond the limit set for gaseous fuels (in the range 0.9 to 1.1). In high altitudes where the atmospheric pressure is low, with the atmospheric pressure below the normal atmospheric pressure of 1 bar, the air density is less and air pressure is less, which implies less air flow is obtained at the carburetor, hence poor startability is observed. Low battery voltage may result in slow or no operation of a starter motor, which may result in difficulty of operation of cranking the internal combustion engine by physical effort. Additionally, sometimes the air induction system may become clogged which can prevent sufficient atmospheric air to enter into the air induction system. Additionally, even if the internal combustion engine manages to start in such above mentioned conditions, the internal combustion engine operation may misfire and become unstable.
[0009] A possible solution to address this issue, at the time of starting of the internal combustion engine, is to have a precise control of gaseous fuel supply. Electronic fuel injection supply systems are very advantageous as it can deliver exactly a metered quantity of air and fuel mixture directly to the internal combustion engine. However, the disadvantages of the electronic fuel injection supply system are that, it is very expensive, as for closed loop operations compared to a carburetor fuel supply system additional components need to be installed. Additionally, if fuel injection supply system fails, serviceability is difficult and also service in-field is expensive. Other solutions include, using liquid fuel to achieve engine start before switching over to gaseous fuel mode. But these systems are also disadvantageous as emissions during start of internal combustion engine may be more and the transition from liquid fuel to gaseous fuel after start can cause excess fuel consumption and hence the automobile will not be able to meet efficiency requirements. Other methods include heating of gaseous fuel at the time of starting and fuel enrichment and providing additional gaseous fuel supply with improved combustibility properties. Such systems involve complicated circuitry and expensive components and use additional fuels which add cost, additional fuel is difficult to obtain and has additional maintenance requirements.
[00010] Hence, it is the object of the present invention to provide a reliable system for starting an internal combustion engine fuelled by gaseous fuel.
[00011] Another object of the present invention is to ensure least modification in the layout of the automobile in which the internal combustion engine is used.
[00012] Another object of the present invention is to provide a reliable starting system that can start at any operating conditions.
[00013] Another object of the present invention is to provide the system for starting a carburetted internal combustion engine without the use of expensive components and elements such as electronic fuel injection supply systems.
[00014] Another object of the present invention is to integrate the controller which controls the starting system with the transistor controller ignition unit.
[00015] With the above design changes, the following advantages can be obtained such as providing for a reliable starting system, no additional effort needed by the driver of the automobile other than to crank the automobile by operation of an ignition switch, the system provides a very inexpensive alternative to use of other expensive components and systems hence saving costs and absolutely no changes in automobile layout or additional elements or circuitry is required. Only mechanical systems are involved, lesser emissions during start and the controller unit can be integrated with the transistor controlled ignition unit.
[00016] According to the present invention to attain the above mentioned objectives, there is provided a system for starting an internal combustion engine fuelled by gaseous fuel which comprises, one or more sensors to acquire internal combustion engine operational data, a fuel storage assembly capable of storing gaseous fuel, and a fuel supply system disposed between the fuel storage assembly and the internal combustion engine capable of controlling and supplying gaseous fuel to the internal combustion engine. The fuel supply system further comprises of a fuel control valve configured to control the flow of gaseous fuel to the internal combustion engine. Accordingly, The fuel control valve is controlled by a fuel controller unit which continuously receives the internal combustion engine operational data from the one or more sensors, and the fuel controller unit determines if there is accumulation of gaseous fuel in the fuel supply system based on the internal combustion engine operational data when attempting to start the internal combustion engine and controls the operation of the fuel control valve based on such determination.
[00017] The system for starting the internal combustion engine according to the present invention is that the fuel controller unit controls the fuel control valve based on the determination whether there is accumulation of gaseous fuel in the fuel supply system. If, the fuel controller unit detects that, there is accumulation of gaseous fuel during starting of the internal combustion engine, subsequently the fuel control unit will close the fuel control valve. Then, another when subsequent repetitions of starting is attempted, the accumulated gas when is remaining in the fuel supply system is utilized first by the internal combustion engine. The internal combustion engine can be in two states at this point, it can either expel all the accumulated gases through the exhaust valve thus leaving a partial vacuum in the fuel supply system for effective suction and optimum air-fuel ratio, or the internal combustion engine may get started and go into operation. If the fuel controller unit detects any one of these two states, it transmits a signal to open the fuel control valve, thus allowing gaseous fuel from the fuel storage assembly. Then, gaseous fuel enters the partially vacuum space in the fuel supply system and hence, provides an optimum air-fuel ratio which enables start of the internal combustion engine. Thus, this system ensures that it is always possible to start the internal combustion engine at any operating condition.
[00018] Additionally, the fuel supply system according to the present invention comprises of a first stage reduction unit, a second stage reduction unit, and an air-fuel mixer. The fuel control valve is disposed between the first stage reduction unit and second stage reduction unit, and a hose piping connects the second stage reduction unit and the air-fuel mixer. Accordingly, the accumulation of gaseous fuel in the fuel supply system occurs in the substantial volume of the hose piping and second stage reduction unit, when attempting to start the internal combustion engine.
[00019] The determination of the accumulation of gaseous fuel according to the present invention is achieved by counting the number of times by the fuel controller unit, attempts were made to start the internal combustion engine. A predetermined number is programmed to the fuel controller unit, and if the number of attempts made to start the internal combustion engine exceeds the predetermined number, then the fuel controller unit automatically detects that there is accumulation in the fuel supply system and transmits the signal to close the fuel control valve.
[00020] According to one embodiment of the present invention, the fuel controller unit can also be integrated into the TCI controller unit to form a integrated controller unit capable of performing all the functions including functions performed by the TCI controller unit and the fuel controller unit.
[00021] These and other advantages of the present invention would be described in greater detail in conjunction with the figures in the following description.
[00022] Fig. 1 illustrates the system block diagram of the system for starting the internal combustion engine (110) according to the embodiment of the present invention. The operation of the system for starting the internal combustion engine (110) consists of various stages to supply and regulate the gaseous fuel. The system consists of a gas cylinder (101) which stores gaseous fuel at high pressures of about 200 bar. In the embodiment of the present invention, the gaseous fuel stored in the gas cylinder is compressed natural gas fuel (CNG gas). There is a fuel supply system disposed between the gas cylinder (101) and the internal combustion engine (110). The fuel supply system comprises of various components which perform specific functions before CNG gas can reach the internal combustion engine (110).
[00023] The gas cylinder (101) has an exit on which a first stage reduction unit (104) is connected. CNG gas is stored in the gas cylinder at 200 bar, and the first stage reduction unit (104) has a high pressure lock off valve (not shown) and a filter (not shown) which reduced the pressure to about 5 to 8 bar. The first stage reduction unit (104) also includes a circular handwheel (119) through which any person can open the regulator to allow the CNG gas flow or can close it by turning the handwheel (119), and a pressure gauge (103). The pressure gauge (103) can either be mounted on a body panel or on the mouth of the first stage reduction unit (104), and the pressure gauge (103) indicates the gas pressure inside the tank and high pressure line. The first stage reduction unit (104) is connected to the second stage reduction unit (116) through a first fuel supply hose (105).
[00024] The high pressurized CNG gas needs to be reduced to almost atmospheric pressure before it reaches the carburetor (113). This because, the atmospheric air is at normal atmospheric pressure of close to 1 bar. Hence, the fuel and air will not mix, or improper mixture will occur if the pressure of the gaseous fuel is greater than atmospheric pressure. Hence, to reduce the pressure, CNG gas is made to pass through two stages. In the first stage reduction unit (104), the high 200 bar pressure CNG is reduced to 5 bar pressure. Then it passes through a second stage reduction unit (116) which reduces the 5 -8 bar pressure to almost atmospheric pressure of 1 bar. This pressure enables the easy mixing of atmospheric air and CNG gas at same pressures. The other end of the first fuel supply hose (105) connects to a second stage reduction unit (116). There is a fuel control valve, such as a gas solenoid valve (102) which is disposed between the first stage reduction unit (104) and second stage reduction unit (116). This gas solenoid valve (102) controls the flow of CNG gas, by opening or closing the gas solenoid valve (102) based on signals sent to it by a fuel controller unit (111). The second stage reduction unit (116) controls and meters the flow according to the internal combustion engine speed and load requirements.. A second fuel supply hose 118 connects the second stage reduction unit (116) to a air-fuel mixer (112). The function of the air-fuel mixer (112) to permit good mixing of CNG gas and fuel. Atmospheric air is sucked through the air filter assembly (106) and connected to the air-fuel mixer (112). The air-fuel ratio is determined in the air-fuel mixer (112). The carburetor (113) is located just at the exit of the air-fuel mixer (112) and adjusts the amount of air-fuel mixture based on the throttle control by the driver. This controlled air-fuel mixture enters the internal combustion engine (110) which gets combusted inside and generates work, which ultimately drives the automobile.
[00025] The internal combustion engine (110) includes a starter system (108) and other systems such as exhaust system (not shown), transmission system (not shown), cooling system (not shown) and lubrication system (not shown). The starting system includes a starter motor (108) and a mechanical starter mechanism (not shown) for aiding in cranking the internal combustion engine (110). The electrical starter system is powered by an auxiliary power source and operated by the driver by means of an ignition switch (not shown).
[00026] Since, the same internal combustion engine (110) and same design can be used to combust conventional fuels such as petrol. A reserve petrol tank (107) is also present which can drive the internal combustion engine (110) in absence of gaseous fuel. The liquid fuel supply system comprises of a liquid fuel solenoid valve (109) which controls the flow of liquid fuel to the carburetor (113). The liquid fuel solenoid valve (109) can be opened whenever the running of the internal combustion engine (110) using liquid fuel is desired.
[00027] In the embodiment of the present invention, the internal combustion engine (110) is started by controlling the gas solenoid valve (102). For this purpose, a fuel controller unit (111) is used. The engine startability depends on the operating conditions of the automobile, which in turn depends on the quality of air-fuel mixture entering the internal combustion engine (110) due to those operating conditions. When, the ignition switch is switched on, the starter motor (108) cranks the internal combustion engine (110) in an attempt to crank it. The fuel controller unit (111) will read the engine state and number of cranks. Based on these input signals, the fuel controller unit (111) will switch-off the gas solenoid valve (102). This will prevent further fuel from flowing out of the gas cylinder. There is residual fuel left behind in the entire fuel supply lines from the gas cylinder (101) to the internal combustion engine (110). Additionally some air-fuel mixture is also left in the air-fuel mixer (112) land in the carburettor (113). Once the fuel controller unit (111) closes the gas solenoid valve (102), another start is attempted by cranking the internal combustion engine (110). The dead cranks help expel all the residual fuel and air-fuel mixture from the internal combustion engine cylinder. This discharges the gaseous fuel in the supply lines and the residual air-fuel mixture. This also creates a strong vacuum to cause suction of atmospheric air through the air induction system more effectively. The gas solenoid valve (102) is opened after a few dead cranks by the fuel controller unit (111). CNG gas flows through the fuel supply lines and optimum air-fuel ratio is perfectly obtained to operate the internal combustion engine (110).
[00028] Fig. 2 illustrates a methodology of the system for starting an internal combustion engine according to the embodiment of the present invention. The method may be described in the general context of computer executable instructions, and communications sent and received to other elements in the system. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, and the like that perform particular functions or implement particular abstract data types. The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method, or alternate methods. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof as will be explained in another embodiment. Furthermore, the method can be implemented in other similar systems albeit with a few variations as will be best understood by a person skilled in the art.
[00029] When the ignition switch is operated initially from the time the automobile is at rest, the gas solenoid valve is initially kept open. The method consists of two major steps that must be taken, each major step consisting of a plurality of method blocks. The two major steps are check condition (201) and expel condition (202). The check condition (201) collectively has a plurality of steps represented as blocks (203, 204, 205, 206 and 207) to check whether accumulation of CNG gas is there in the fuel supply system. The expel condition (202) collectively has a plurality of steps represented as blocks (210, 211, 212, 213 and 214) and it expels the accumulated CNG gas from the fuel supply system, thus providing ideal conditions for start of the internal combustion engine (110).
[00030] The check condition (201) to check for accumulated CNG gas in the fuel supply system comprises the following steps. At block (203), an attempt is made by the driver to start the internal combustion engine (110) by operation of the ignition switch. Subsequently, at block 204 the fuel controller unit (111) receives the internal combustion engine operational data from one or more sensors on the internal combustion engine (110). The sensors can be mounted at any one the various locations in the internal combustion engine (110) to receive operational data. In the embodiment of the present invention the sensor is mounted at an engine magneto assembly (not shown) of the internal combustion engine (110) and it is designed to sense engine revolutions and communicate the same to the fuel controller unit (111). At block (205) a count is initiated by the fuel controller unit (111) counting the number of times attempts have been made to start the internal combustion engine (111) by operation of the ignition switch. At block 206, based on engine revolutions received, a determination is made whether the internal combustion engine (110) has started or still in cranking mode and unable to start. The determination is made by satisfying the following conditions. It is known in theory that starter motor revolutions are between range 400 – 500 revolutions per minute. The maximum cut-off limit for detecting starter motor revolution is 600 revolutions per minute. Whereas, automobile idling revolutions always exceed 1000 revolutions per minute when the internal combustion engine (110) is in running mode. Hence, the fuel controller unit keeps the cut-off in the range of a predetermined engine revolution value of below 600 revolutions per minute to detect engine cranking but has not started. Additionally, in order to avoid any error in detection, a predetermined time limit of around 50 to 100 milliseconds is provided. If the answer to the determination is ‘no’, the next step to block (207) is proceeded to, If the answer to the determination is ‘yes’ and engine revolutions is more than 600 revolutions per minute for a time period of 50-100 milliseconds, then the internal combustion engine (110) has started and is in operation and the next step is to directly move to block (216). At block (205), the number of attempts made at starting is compared to a predetermined count value. If it does not match, this operation is repeated for another attempt at starting where the driver operates the ignition switch. Once, the count is equal to the predetermined first count value, the step moves to block (208). The plurality of steps (203, 204, 205, 206 and 207) is repeated for a predetermined number of times if the conditions at block (206) are not satisfied. This repetition of steps acts as a check to detect if there is accumulation of gases in the fuel supply system, as if the internal combustion engine (110) is not started for a predetermined number of attempts at starting, that means that fuel is accumulated. In the embodiment of the present invention, the predetermined first count value is two.
[00031] The next step the check condition (201) is executed is at block 208, where the fuel controller unit (111) sends a first signal to the fuel control valve, namely the gas solenoid valve (102) to close it, so as to shut the CNG gas supply. At block 209, based on the communication received by the fuel controller unit (111) in the preceding step, the gas solenoid valve (102) can be closed.
[00032] The check condition (201) to expel the accumulated CNG from the fuel supply system comprises the following steps. At block (210), another attempt is made by the driver to start the internal combustion engine (110) by operation of the ignition switch. Subsequently, at block (211) the fuel controller unit receives the engine revolutions and communicate the same to the fuel controller unit (111). At block (212) another count is initiated by the fuel controller unit (111) counting the number of times attempts have been made to start the internal combustion engine (110) by operation of the ignition switch during expel condition (202). At block (213), based on engine revolutions received, a determination is made whether the internal combustion engine (110) has started or still in cranking mode and unable to start. This determination is made by satisfying the same conditions as that of block (206). Therefore, a determination is made to check if the engine revolutions is greater than 600 revolutions per minute and last for about 50-100 milliseconds. At block (214), the number of attempts made at starting is compared to a predetermined count value. If it does not match, this operation is repeated for another attempt at starting where the driver operates the ignition switch. Once, the count is equal to the predetermined second count value, the step moves to block (215). The main objective in the plurality of steps executed in the expel condition (202), is to crank the internal combustion engine (110) in order to utilize or discharge the accumulated gases in the fuel supply system. By repetitions of dead cranks for a predetermined number of times, the accumulated CNG is either expelled, or aid in starting the internal combustion engine. If the internal combustion engine (110) starts at block (213), the determination at block (213) is “yes” and the next step directly proceeds to step (216). If the determination is “no”, then, the plurality of steps in expel condition is repeated for a predetermined number of times before proceeding to the next block (215). In the embodiment of the present invention, the predetermined second count value is one.
[00033] The next step after the expel condition (202) is executed, is at block 215 where the fuel controller unit (111) sends a first signal to the fuel control valve, namely the gas solenoid valve to open it, so as to open the CNG gas supply. At block 209, based on the communication received by the fuel controller unit (111) in any of the steps (206), (213) or (215), the gas solenoid valve (102) is kept open. At the end of this step, the accumulated gases are expelled from the fuel supply system, during the next start attempted, optimum air-fuel ratio is obtained, creating ideal conditions to start the internal combustion engine (110) and run the automobile.
[00034] Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.
,CLAIMS:We Claim:
1. A system for starting an internal combustion engine (110) fuelled by gaseous fuel, said system comprising:
one or more sensors (130) to acquire internal combustion engine operational data;
a fuel storage unit (101) capable of storing gaseous fuel;
a fuel supply unit (150) disposed between the fuel storage unit (101) and the internal combustion engine (110) capable of controlling and supplying gaseous fuel to the internal combustion engine (110), said fuel supply unit (150) comprising a fuel control valve (102) configured to control the flow of gaseous fuel to the internal combustion engine (110);
wherein,
the fuel control valve (102) is controlled by a fuel controller unit (111), said fuel controller unit (111) continuously receives said internal combustion engine operational data from said one or more sensors (130), and said fuel controller unit (111) determines if there is accumulation of gaseous fuel in the fuel supply assembly based on the internal combustion engine operational data when attempting to start the internal combustion engine (110) and controls the operation of the fuel control valve (102) by closing the fuel control valve (102) by transmitting a first control signal, and opening the fuel control valve (102) by transmitting a second control signal based on such determination.
2. The system for starting the internal combustion engine (110) fuelled by gaseous fuel as claimed in claim 1, wherein the fuel supply unit further comprises,
a first stage reduction unit (104);
a second stage reduction unit (116),
said fuel control valve (102) being disposed between the first stage reduction unit (104) and second stage reduction unit (116);
an air-fuel mixer (113);
a hose piping connecting the second stage reduction unit (116) and the air-fuel mixer (113).
3. The system for starting the internal combustion engine (110) fuelled by gaseous fuel as claimed in claim 1, wherein said one or more sensors (130) is a rpm sensor configured to acquire engine revolutions.
4. The system for starting the internal combustion engine (110) fuelled by gaseous fuel as claimed in claim 1, wherein the starting of the internal combustion engine (110) is effected by operation of an ignition switch (114) which supplies power to an electric motor (108) coupled to the internal combustion engine (110).
5. The system for starting the internal combustion engine (110) fuelled by gaseous fuel as claimed in claim 1, wherein the fuel controller unit (111) can be integrated with an electronic control unit used to control the internal combustion engine performance.
6. A method (200) for starting an internal combustion engine (110) fuelled by gaseous fuel, said method comprising steps of:
attempting, by operation of a ignition switch (114) to start the internal combustion engine (110);
receiving, by a fuel controller unit (111), internal combustion engine operational data from one or more sensors (130);
determining, by the fuel controller unit (111), whether there is accumulation of gaseous fuel in a fuel supply unit (150) when attempting to start the internal combustion engine (110), and transmitting a first control signal to close a fuel control valve (102) based on such determination;
detecting, by the fuel controller unit (111), whether the accumulated gaseous fuel in the fuel supply unit (150) has been utilized when attempting to start the internal combustion engine (110) during the period the fuel control valve is closed (102); and
transmitting, by the fuel controller unit (111), a second control signal to open the fuel control valve (102) on complete utilization of accumulated gaseous fuel in the fuel supply unit (150).
7. The method (200) for starting the internal combustion engine fuelled by gaseous fuel as claimed in claim 6, wherein the internal combustion engine operational data is number of internal combustion engine revolutions per minute.
8. The method (200) for starting the internal combustion engine fuelled by gaseous fuel as claimed in claim 7, wherein the method of determining, by the fuel controller unit (111), whether there is accumulation of gaseous fuel in the fuel supply unit (150) when attempting to start the internal combustion engine (110) further comprises steps of:
Counting, by the fuel controller unit (111), the number of attempts at starting the internal combustion engine (110);
determining, by the fuel controller unit (111), whether the number of internal combustion engine revolutions is greater than a predetermined engine revolution value, and remain greater for a predetermined time the starting of the internal combustion engine is attempted;
checking, by the fuel controller unit (111), if number of counts is equal to a first predetermined count value, else repeating the attempt to start the internal combustion engine (110) by operation of a ignition switch (114).
9. The method for starting the internal combustion engine (110) fuelled by gaseous fuel as claimed in claim 7, wherein the method of detecting, by the fuel controller unit (111), whether the accumulated gaseous fuel in the fuel supply system has been utilized when attempting to start the internal combustion engine (110), further comprises steps of:
Counting, by the fuel controller unit (111), the number of attempts at starting the internal combustion engine (113);
determining, by the fuel controller unit (111), whether the number of internal combustion engine revolutions is greater than a predetermined engine revolution value, and to remain greater for a predetermined time the starting of the internal combustion engine (110) is attempted;
checking, by the fuel controller unit, if number of counts is equal to a first predetermined count value; else repeating the attempt to start the internal combustion engine (110) by operation of a ignition switch (114).
10. The method for starting the internal combustion engine (110) fuelled by gaseous fuel as claimed in claim 8 or claim 9, wherein the predetermined engine revolution value is in the range between 500 to 600 engine revolutions per minute, and wherein the predetermined time is in the range between 50 to 100 milliseconds.