INTERNAL COMBUSTION ENGINE

RELATED APPLICATION Benefit is claimed to India Provisional Application No. 4486/CHE/2011 , entitled "DUAL SOURCED HYDROGEN FUEL CELL FOR GENERATING HYDROGEN TO RUN AN INTERNAL COMBUSTION ENGINE AND THE METHOD INVOLVED THEREOF" by Sounthirarajan Kumarasamy, filed on 21 ^st December 2011 , which is herein incorporated in its entirety by reference for all purposes.

FIELD OF THE INVENTION

The present invention generally relates to a method and a system for generating hydrogen. More specifically, the present invention relates to the method and the system for generating hydrogen by utilizing heat exerted from an internal combustion engine.

BACKGROUND OF THE INVENTION It is known in the art to use the hydrogen as a fuel for an internal combustion engine. Electrolysis may be performed to obtain hydrogen from the water. The hydrogen is utilized as the fuel in the internal combustion engine. The method involves usage of appropriate electrolyte and electrodes to perform the electrolysis. However, employment of such methods resulted in high consumption of electric current that go beyond the affordability and cost effectiveness. The primary reason for this may be improper matching of techniques of electrolysis with scale of requirement of hydrogen.

Further, the storage of hydrogen is one of the hurdles in using hydrogen as a fuel. Hydrogen is a gas with very low flash point and is highly inflammable: Thus, the cost incurred in deploying complex apparatus to store hydrogen is high. Although, different techniques are adapted to store the hydrogen, safety concerns are high in magnitude and often positions the life of a user at stake. Especially, when the hydrogen -is to be stored in the vicinity of the internal combustion engine, the risk factors associated with the storage is relatively high compared to other fuels.

SUMMARY OF THE PRESENT INVENTION

One aspect of the present invention is to provide a device for generating hydrogen for use in an internal combustion engine is disclosed. The device includes an electrolytic device adapted for receiving water from a water source and converting the high temperature water to hydrogen and oxygen through electrolysis. The device further includes one or more heat transferring units thermally connected to the electrolytic device, the one or more heat transferring units are adapted to assist in maintaining temperature of desired range at the electrolytic device. The device furthermore includes one or more selective conduction layers positioned between the electrolytic device and the one or more heat transferring units, the one or more selective conduction layers are adapted to permit heat transfer from the heat transferring units to the electrolytic device and prevent electric conduction between the electrolytic device and the one or more heat transferring units.

The device also includes a first conduit connected between the electrolytic device and the water source for transporting said water from the water source to the electrolytic device. The first conduit is thermally coupled to the internal combustion engine so that temperature of water from the water source is raised to the desired range due to heat conduction between the first conduit and the internal combustion engine.

The electrolytic device as mentioned includes a membrane which is configured to receive the high temperature water from the water source, a frame enclosing the membrane, at least two metal mesh plates attached to a first side and a second side of the membrane to facilitate electrolysis of the water at the high temperature, and electrodes are attached to the at least two metal mesh plates, wherein the electrodes are configured to attract hydrogen and oxygen ions from the membrane of water when electricity is supplied.

Another aspect of the present invention is to provide a system for generating hydrogen. The system includes an internal combustion engine configured to function with one or more fuels and a hydrogen generating unit thermally coupled to the internal combustion engine. The hydrogen generating unit includes an electrolytic device receiving said water from a water source. The electrolytic device is configured to convert water to hydrogen and oxygen by performing electrolysis. The system further includes one or more heat transferring units thermally connected to the electrolytic device. The one or more heat transferring units are configured to assist in maintaining a desired temperature at the electrolytic device by utilizing heat generated at the internal combustion engine. The system furthermore includes one or more selective conduction layers positioned between the electrolytic device and the one or more heat transferring units. The one or more selective conduction layers are configured to permit heat transfer and prevent electric conduction between the electrolytic device and the one or more heat transferring units. The system according to one aspect includes a power distributor configured to provide current to the hydrogen generating unit. The system furthermore includes a shell and tube type heat exchanger configured to reduce the temperature of hydrogen gas generated by the hydrogen generating unit. A purifier connected to the hydrogen generating unit is configured to purify hydrogen generated by the hydrogen generating, unit. The purifier includes a palladium membrane. The system may also include a compressor configured to increase the pressure of the hydrogen gas generated by the hydrogen generating unit. The compressed gas is stored in a metal hydride tank. The pressure in the tank is controlled by pressure control device. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 illustrates an exemplary block diagram of a system for generating hydrogen according to an embodiment of the present invention.

Figure 2 is a disassembled or exploded view of a hydrogen generating unit according to an embodiment of the present invention.

Figure 3 illustrates a system for generating hydrogen according to an embodiment of the present invention.

Figure 4 illustrates a disassembled view of an electrolytic device used in a hydrogen generating unit according to an embodiment of the present invention.

Figure 5 illustrates a perspective view of a metal layer used in a hydrogen generating unit according to an embodiment of the present invention. Figure 6 illustrates a perspective view of a thermal conduction layer used in a hydrogen generating unit according to an embodiment of the present invention.

Figure 7 is a flow chart illustrating a method for generating hydrogen from water according to an embodiment of the present invention.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION OF THE INVENTION

The present invention details a system or apparatus or a device or a unit that is associated with an internal combustion engine to generate hydrogen. The generated hydrogen is utilized for providing the internal combustion engine as a fuel or a supplement fuel. Following description of drawings provide certain implementations of the present invention and not cover scope of the invention. The scope of the invention is to be interpreted only through claims section following the description. Figure 1 illustrates an exemplary block diagram of a system 100 for generating hydrogen according to an embodiment of the present invention.

In accordance with an embodiment of the. present invention, the system 100 includes a water source 102, a power distributor 103, a pump 104, an internal combustion engine 105, a hydrogen-generating unit 106, an oxygen reservoir 108, a bubbler 110, a heat exchanger 112, a hydrogen gas purifier 114, a hydrogen reservoir 118, a compressor 116, a valve 119 and a fuel injector 120.

The water source 102 in accordance with the current embodiment can be a water reservoir or a container that can hold a required amount of water proportional to the size of the internal combustion engine. Pressure of the water from the water source 102 is increased with the help of the pump 104 which is present in the passage of water. Water is then transferred to the hydrogen- generating unit 106 through a conduit (105a). During the transfer of water through the conduit 105a, heat collected from the internal combustion engine 105 is applied to the conduit 105a by thermally coupling (denoted by dotted circles) with another conduit 105b carrying high temperature exhaust gas from the internal combustion engine 105. In an embodiment, due to the contact of heat from another conduit, the water passing through the conduit is vaporized. (The process will be explained in detail with reference to Figure 2)

Thereafter, the water vapor is passed to the hydrogen generating unit 106. In the hydrogen generating unit 106, the water vapor is split to hydrogen and oxygen gases. In an embodiment, the oxygen released as a byproduct from the hydrogen generating unit 106 is stored in the oxygen reservoir 108. In an embodiment, when the system 100 is utilized in a submarine, the oxygen released from the hydrogen generating unit 106 is used for assisting in maintaining suitable oxygen levels in the submarine. The power distributor 103 is used to distribute power to the hydrogen generating unit 106 and the pump 104. In an embodiment, the power distributor 103 is configured to provide a Direct Current (DC) power supply to both the hydrogen generating unit 106 and the pump 104, wherein the DC power supply is provided from an alternator (not shown in the figure) coupled to the internal combustion engine. In another embodiment, type of current supplied from the power distributor 103 can be Alternating Current (AC) and an AC to DC adapter to be used. The hydrogen liberated from the hydrogen generating unit 106 is passed through the bubbler 110. The bubbler 110 is configured to assist in determining the continuous generation of hydrogen. When, the hydrogen gas passes through the bubbler 110, the temperature of the hydrogen is reduced due to contact with the water. Thereafter, the hydrogen is passed through the heat exchanger 112 for < cooling the gas. In a preferred embodiment, the heat exchanger 112 used is of shell and tube heat exchanger type where a stream of water is used to pass in contact with the hydrogen carrying conduit. The step of passing the hydrogen through the heat exchanger is to reduce the temperature of the hydrogen gas. Particularly, for the convenience of explanation, a hydrogen gas transferring tube (not shown in the figure) is introduced to a stream of water flow to conduct the heat carried by the hydrogen gas.

Hydrogen gas is then passed to a purifier 114. In an embodiment, the purifier 114 is a palladium membrane purifier. The purified hydrogen is compressed by the compressor 116. In an embodiment of the present invention, the compressor 116 may include a compressor motor, a compressor regulator and a power supply unit (not shown in the figure). The compressor 116 is powered through the power distributor 103. Thereafter, the compressed hydrogen gas is transferred to the hydrogen reservoir 118. The hydrogen reservoir 118 may include an inlet tube and an outlet tube equipped with non-return valves (not shown in the figure). In an embodiment, the hydrogen reservoir 118 is made of materials such as metal hydrides. The hydrogen reservoir 118 is connected to a valve 119. The valve 119 is a variable flow control valve or with a variable orifice. The hydrogen gas is transferred to the fuel injector 120 to introduce it to the internal combustion engine. By transferring the hydrogen gas to the fuel injector 120, the probability of backfiring in the internal combustion engine during combustion cycle is reduced.

Figure 2 is an exploded or disassembled view of the hydrogen generating unit 106 according to an embodiment of the present invention.

The hydrogen generating unit 106 includes plurality of components to facilitate generation of hydrogen from the water vapor. The hydrogen generating unit 106 includes a first inlet 202, a second inlet 204, a first conduit 206, a second conduit 208, heat transferring units 210, a connecting tube 212, an electrolytic device 214, thermal conduction layers 216, metal conducting layers 218, a hydrogen conduit 220, an oxygen conduit 222, a thermal insulator junction 226, and a thermal insulation 230.

The hydrogen generating unit 106 is thermally coupled to an internal combustion engine (not shown in the figure). In an embodiment, the thermal coupling is established by receiving hot exhaust gas at the hydrogen generating unit 106 from the internal combustion engine. In the same embodiment, the first inlet 202 of the first conduit 206 is provided with a thermal insulator junction 226 to withstand the heat provided by another conduit 105b from the internal combustion engine. The exhaust heat from the internal combustion engine is received at the first conduit 206 from another conduit 105b. In the current embodiment of the present invention, the exhaust heat is collected from a single tube, another conduit 105b. However, there can be multiple conduits or a manifold connected to the internal combustion engine because the internal combustion engine may have multiple combustion cylinders to suit the requirement. More the number of cylinders, more heat can be generated from the exhaust gases. The increase in heat may result in increased rate or evaporation of water passing through the second conduit 208. The first conduit 206 and the second conduit 208 are thermally coupled (denoted by dotted circular). The heat from the first conduit 206 is transferred to the second conduit 208. Water passing through the second conduit 208 is vaporized with the aid of heat from the first conduit 206.

Thereafter, the vaporization of water can be either instantaneous or can occur over a period of time. The second conduit 208 transfers the water vapor to the electrolytic device 214. Before transferring the water vapor to the electrolytic device 214, the water vapor passes through a first segment of the heat transferring units 210 which receives the hot exhaust gas from the first conduit 206. A second segment of heat transferring units 210 is present at the other side of the electrolytic device 214. The heat transferring units 210 are configured to increase the temperature of the second conduit 208 as well as the hydrogen generating unit 106. Thus, the heat transferring units 210 are positioned on the either sides of the hydrogen generating unit 106. Further, the heat transferring units 210 that are present in the either sides are connected through the connecting tube 212. The connecting tube 212 enables transfer of exhaust gas between two segments of the heat transferring units 210. The exhaust gas is then emitted through a third conduit 224. The heat transferring units 210 assist in maintaining high temperature range in the hydrogen generating unit 106 to facilitate electrolysis. Post to the completion of electrolysis of the water vapor, gaseous atomic hydrogen and oxygen are generated. The oxygen generated through the process is transferred thorough the oxygen conduit 222 and the hydrogen generated is transferred through the hydrogen conduit 220.

Further, the metal layers 218 are made of one of the materials among nickel, copper, mild steel, stainless steel, or alloys thereof. In an exemplary embodiment, the metal layers 218 are configured to conduct heat from the heat transferring units 210 to the thermal conduction layers 216. In an embodiment, the type of electrolysis performed in the electrolytic device 214 is high- temperature electrolysis or steam electrolysis. When part of energy is supplied as heat to the electrolytic device 214 in the high temperature electrolysis, the electrolytic process is more efficient. Between the metal layers 218 and the electrolytic device 214, thermal conduction layers 216 are positioned. The thermal conduction layers 216 are configured to transfer heat from the heat transferring units 210 and prevent electrical conduction between the metal layers 218 and the electrolytic device 214. In an embodiment of the present invention, the thermal conduction layers 216 are made of materials such as mica. Any material that is thermally conducting and electrically non-conducting or resistant can be used in the thermal conduction layers 216. In an embodiment, the thickness of the thermal conduction layers 216 is in the range of 0.5 mm to 3 mm. In an embodiment, a combination of the thermal conduction layers 216 and the metal layers 218 is called as selective conduction layers. Working Principle:

Water from the water source 102 is transferred through the second conduit 208. Due to the thermal coupling between the first conduit 206 and the second conduit 208, water in the second conduit 208 is vaporized. The water vapor is then transferred to the electrolytic device 214. When an electric current is passed through the electrolytic device 214, the hydrogen and oxygen gases are generated from the water vapor as a result of electrolytic dissociation. The hydrogen gas is transported with the aid of the hydrogen conduit 220 and the oxygen gas is transported with the aid of the oxygen conduit 222. A constant high working temperature is maintained at the electrolytic device 214 by the heat transferring units 210 and thermal insulation 230. The thermal insulation 230 may enclose the hydrogen generating unit 106 and prevent heat transfer between the hydrogen generating unit 106 and the atmosphere. This may increase the efficiency of electrolysis as additional energy required for electrolytic dissociation is provided in the form of heat.

Figure 3 illustrates a system 300 for generating hydrogen according to an embodiment of the present invention.

The system 300 for generating hydrogen includes components or elements that constitute the system 100 and the hydrogen generating unit 106. In addition, the system 300 in accordance with the present embodiment includes individual cylinder heads 302 of the internal combustion engine 105, an alternator 304, and a hydrogen supply line 306. The internal combustion engine 105 includes cylinder heads 302, as displayed in the figure. In the current exemplary embodiment, the internal combustion engine 105 has four cylinder heads 302. However, any number of cylinders may be present in the internal combustion engine 105. Each of the cylinder heads 302 is connected to the conduit 105b. The exhaust gas from the outlet (not shown) is collected from the internal combustion engine 105 at the conduits 105b. The conduits 105b are thermally coupled to the second conduit 208. The second conduit 208 is configured to carry water from the water source 102. The pump 104 is configured to increase pressure of the water. Due to heat from the exhaust gas in the conduits 105b, the water in the second conduit 208 is vaporized. In the current exemplary embodiment, the second conduit 208 is wound around the conduits 105b. The second conduit 208 traverses through one of the heat transferring units 210. The water vapor is then transferred at constant or variable rate to the hydrogen generating unit 106.

Electrolysis is performed at the hydrogen generating unit 106 to dissociated water vapor from the second conduit 208 to hydrogen and oxygen gas. The electricity for performing electrolysis is provided by the power distributor 103. In an embodiment, the power distributor 103 obtains power from the alternator 304 which is rotationally coupled to the internal combustion engine 105. The hydrogen gas, thus generated is transported through the hydrogen conduit 220, as represented in the diagram. The hydrogen gas in the hydrogen conduit 220 is transported to the compressor 116 to increase the pressure and stored in the reservoir 118. For example, the reservoir 118 may be made of metal hydride material. The metal hydride reservoirs are used to increase the safety in the system 300, as hydrogen has a low flash point.

The hydrogen from the reservoir 118 is channelized through the hydrogen supply line 306 to the fuel injectors 120. In the present embodiment, four fuel injectors 120 are provide, where each of the fuel injectors 120 correspond to the respective internal combustion engine cylinders). In an embodiment, the fuel injectors 120 provided are of gas fuel injector type. However, other types of fuel injectors can also be used. The pressure and velocity of the hydrogen gas is increased by the fuel injectors 120 and supplied to the cylinder heads 302. The combustion occurs in the internal combustion engine 105 which releases high temperature exhaust with an approximate temperature range of 200 degrees centigrade to 1000 degrees centigrade. Thus, a cycle of generating hydrogen and introducing into the internal combustion engine 105 is continued. Excess hydrogen created is stored in the hydrogen reservoir 118 at a desired pressure.

Figure 4 illustrates a disassembled view of the electrolytic device 214 used in the hydrogen generating unit 106 according to an embodiment of the present invention.

The electrolytic device 214 includes a membrane 402, a frame 404, metal mesh plates 406, and anode plate 408 and cathode plate 410. The electricity that is to be supplied to the electrolytic device 214 is connected to the anode plate 408 and the cathode plate 410. In an embodiment of the present invention, the anode plate 408 and the cathode plate 410 are made of Nickel, Copper, Aluminum, and alloys thereof. The membrane 402 has the metal mesh plates 406 attached to either side. In an embodiment, the membrane 402 is made of ceramic. In an embodiment, the metal mesh plates 406 are made of stainless steel alloy. For instance, the metal mesh plates 406 are configured to spread high temperature water vapor on the membrane 402. The membrane 402 is enclosed with the frame 404 top side, bottom side and sideways. In an exemplary embodiment, the frame is made of a material which is a mixture of silica and rubber at suitable proportions. The water vapor is supplied to reach the membrane 402. When the water vapor touches the membrane 402, electricity is in supply with the anode plate 408 and the cathode plate 410. Due to the electricity, the hydrogen ions are attracted towards the cathode plate 410 and the oxygen ions are attracted towards the anode plate 408. Thereafter, the collected oxygen is transported through the oxygen conduit 222 which is attached to the anode plate 408. The collected hydrogen at the cathode plate 410 is transported through the hydrogen conduit 220. Performing electrolysis when water is at a vapor phase is one of the biggest advantages of the present invention. The amount of electricity required to split hydrogen and oxygen ions from water molecules is very less. For example, a 12 volt direct current power supply with 2 to 10 amperes of current may perform splitting of hydrogen and oxygen ions, at a constant rate. This advantage is exploited in the present invention.

Figure 5 illustrates a perspective view of the metal plates 218 used in the hydrogen generating unit 106 according to an embodiment of the present invention.

In accordance with an embodiment of the present invention, the metal plates 218 are made of materials such as mild steel, stainless steel, aluminum, copper, nickel, zinc, and alloys thereof. The primary purpose of the metal plates 218 in the hydrogen generating unit 106 is to conduct heat from the heat transferring units 210. In accordance with an embodiment of the present invention, one or more holes are made in the metal plates 218 to transport the water vapor to the electrolytic device 214 and hydrogen and oxygen from the electrolytic device 214.

Figure 6 illustrates a perspective view of the thermal conduction plate 216 used in the hydrogen generating unit 106 according to an embodiment of the present invention. In accordance with an embodiment of the present invention, the thermal conduction plate 216 is made of materials such as mica. One or more holes can be created in the thermal conduction plate 216 to facilitate assembly of conduits that transport gases (water vapor, hydrogen and oxygen) to and from the electrolytic device 214.

Figure 7 is a flow chart illustrating a method 600 for generating hydrogen from water according to an embodiment of the present invention. The method 700 includes plurality of steps to generate hydrogen from water. The method 700 starts at a step of 702, where the process of generating hydrogen is initiated. The power distributor 103 is activated at the step 702 to supply power to components such as the hydrogen generating unit 106, the compressor 18, and the pump 104. Due to continuous running of the internal combustion engine, heat is continuously generated. The heat generated by the internal combustion engine is collected at a step 704. The heat is collected through one or more conduits. One of the techniques to collect heat from the internal combustion engine is by coupling individual exhaust conduits (in case of multi-cylindered engine) to individual water transporting conduits and transfer heat. Another technique is to couple exhaust manifold (collection of exhaust conduits) to a unified water transporting conduit to. Yet another technique can be by combining individual exhaust conduits to the exhaust manifold. While each of the techniques has its own advantage, the application of the technique is based on the environment of hydrogen generation. The techniques are mentioned here to establish a broader application of the present invention. At step 706, due to conduction of heat from the exhaust conduits (the first conduit 206 in the present invention) to the water transporting conduit (the second conduit 208 in the present invention), water is evaporated to form water vapor. For example, the average temperature present in the exhaust conduits may lie in the range of 200 degrees Celsius to 1000 degrees Celsius (depending on the technique as explained before). This temperature may be suitable for conversion of water to water vapor over a predetermined time. The water vapor is then electrolyzed at a step 708. Initially, water vapor of high temperature range is transferred to the electrolytic device 214 (explained in detail with reference to Figure 4).

On passing the electric current to the electrolytic device 214, gaseous hydrogen and oxygen atoms are generated from water vapor. At a step 710, the hydrogen generated by the process of electrolysis is cooled. In an embodiment, the hydrogen is transferred through a shell type heat exchanger for the purpose of cooling. Thereafter, the hydrogen is compressed at a step 712. The compressed hydrogen is injected into the internal combustion engine at a step 714 with the aid of fuel injectors. It should be understood that various changes and modifications to the presented embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. Accordingly, it is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.