Engine system, fuel vaporization system and method for vaporizing secondary liquid fuel

Abstract

The invention relates to an engine system, a fuel vaporization system and a method for vaporizing a secondary liquid fuel. The engine system includes an engine, a first fuel injection system, a second fuel injection system, and a fuel vaporization system. The engine includes an intake manifold. The intake manifold is configured to receive charge air. The first fuel injection system is configured to inject a first liquid fuel into the engine. The second fuel injection system is configured to inject a second liquid fuel into the charge air. The second fuel may be different than the first fuel. The fuel vaporization system is configured to heat at least one of (i) the charge air or (ii) the second liquid fuel upstream of a location where the second liquid fuel is injected into the charge air to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Patent Application No. 63 / 594,724, filed on October 31, 2023, the entire contents of which are hereby incorporated by reference herein. Technical Field

[0003] The present disclosure generally relates to dual fuel internal combustion engine systems. Background Art

[0004] Dual fuel internal combustion engine systems include engines that can operate using a mixture of two different fuels. For example, a dual fuel engine can operate using a combination of diesel fuel and a biofuel (or another low carbon fuel) such as ethanol or methanol. Summary of the invention

[0005] One embodiment of the present disclosure relates to an engine system. The engine system includes an engine, a first fuel injection system, a second fuel injection system, and a fuel vaporization system. The engine includes an intake manifold. The intake manifold is configured to receive pressurized air. The first fuel injection system is configured to inject a first liquid fuel into the engine. The second fuel injection system is configured to inject a second liquid fuel into the pressurized air. The second fuel is different from the first fuel. The fuel vaporization system is configured to heat at least one of (i) the pressurized air or (ii) the second liquid fuel upstream of the location where the second liquid fuel is injected into the pressurized air to enhance vaporization of the second liquid fuel.

[0006] In various embodiments, the fuel vaporization system is configured to heat the charge air or reduce air cooling upstream of the location where the second liquid fuel is delivered to the engine. In other embodiments, the fuel vaporization system is configured to heat the charge air downstream of the location where the second liquid fuel is delivered to the engine. In some embodiments, the fuel vaporization system is configured to heat the second liquid fuel upstream of the location where the second liquid fuel is delivered to the engine. In some embodiments, the fuel vaporization system is configured to control the charge air temperature and / or the second liquid fuel based on: (i) the flow rate of the second liquid fuel, and (ii) the fuel type. In various embodiments, the fuel vaporization system is configured to use waste heat from at least one of the engine coolant, the return fuel, and the exhaust or the charge air to heat the second liquid fuel. In some embodiments, the first liquid fuel is diesel fuel and the second liquid fuel is biofuel or another low-carbon liquid fuel.

[0007] Another embodiment of the present disclosure relates to a fuel vaporization system. The fuel vaporization system includes a heating system, a sensor, and a controller. The heating system is configured to be coupled to an engine or a fuel injection system of a dual-fuel engine system, and the dual-fuel engine system is configured to operate using a combination of a first liquid fuel and a second liquid fuel. The heating system is configured to control the heating of the second liquid fuel. The sensor is configured to generate sensor data indicating a fuel condition of the second liquid fuel. The controller is communicatively coupled to the heating system and the sensor. The controller is configured to receive the sensor data from the sensor and control the operation of the heating system based on the fuel condition to heat the second liquid fuel before the second liquid fuel is injected into the engine to enhance the vaporization of the second liquid fuel and / or improve the combustion characteristics of the engine.

[0008] Yet another embodiment of the present disclosure relates to a method for vaporizing a secondary liquid fuel. The method includes receiving data indicating a fuel condition of a second liquid fuel for a dual-fuel engine system. The dual-fuel engine system is configured to operate using a combination of a first liquid fuel and a second liquid fuel. The method also includes controlling operation of a heating system coupled to the dual-fuel engine system based on the fuel condition to heat the second liquid fuel before injecting the second liquid fuel into an engine of the dual-fuel engine system to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

[0009] It should be understood that all combinations of the foregoing concepts and the additional concepts discussed in more detail below are considered to be part of the subject matter disclosed herein. In particular, all combinations of the claimed subject matter appended at the end of this disclosure are considered to be part of the subject matter disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The foregoing features and other features of the present disclosure will become more fully apparent from the following description and the appended claims when read in conjunction with the accompanying drawings. It should be understood that these drawings depict only several embodiments according to the present disclosure and therefore should not be considered to limit the scope of the present disclosure, which will be described with additional specific description and details through the use of the accompanying drawings.

[0011] Figure 1 is a schematic diagram of a fuel vaporization system for a second liquid fuel of a dual fuel engine according to an embodiment.

[0012] Figure 2 is a schematic diagram of a fuel vaporization system for a second liquid fuel of a dual fuel engine that uses waste heat from an exhaust gas recirculation system to heat the second liquid fuel according to an embodiment.

[0013] Figure 3 is a top cross-sectional view through an engine of a dual fuel engine system according to an embodiment.

[0014] Figure 4 is a schematic diagram of a fuel vaporization system for a second liquid fuel of a dual fuel engine, the fuel vaporization system being configured to preheat the second liquid fuel before delivering the second liquid fuel to the engine, according to an embodiment.

[0015] Figure 5 is a block diagram of a controller of a fuel vaporization system for a dual fuel engine system according to an embodiment.

[0016] Figure 6 is a flow chart of a method of ensuring vaporization of a second liquid fuel for a dual fuel engine system according to an embodiment.

[0017] In the following detailed description, reference is made to the accompanying drawings. In the drawings, similar symbols generally identify similar parts unless the context indicates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It should be readily understood that the aspects of the present disclosure generally described herein and shown in the drawings may be arranged, substituted, combined, and designed in a variety of different configurations, all of which are expressly contemplated and constitute a part of the present disclosure. DETAILED DESCRIPTION

[0018] Embodiments described herein generally relate to a fuel vaporization system for a second liquid fuel used in a dual-fuel internal combustion engine system. Such a dual-fuel engine system operates using a combination of a second liquid fuel (e.g., a secondary liquid fuel) and a first liquid fuel (e.g., a primary liquid fuel). The fuel vaporization system is configured to enhance vaporization of the second liquid fuel and / or improve combustion characteristics, such as combustion temperature, generation of nitrogen oxides (NOX) and / or soot, combustion efficiency, etc. The second liquid fuel may be a biofuel or a low-carbon fuel, undergoing one or a combination of the following: (i) heating charge air upstream of the location where the second liquid fuel is injected into the engine system, (ii) heating the mixed air-fuel feed after the second liquid fuel is introduced into the engine system, and / or (iii) heating the second liquid fuel upstream of the location where the second liquid fuel is injected into the engine system.

[0019] As used herein, "charged air" refers to air that has entered the engine system. As used herein, "air-fuel feed" refers to a mixture of charged air and fuel (e.g., secondary fuel) that passes through the engine system at any point upstream of the combustion cylinders of the engine. It should be understood that any reference to "charged air" herein also covers operating conditions in which the charged air includes a secondary fuel mixed therewith in an optional embodiment (even if not explicitly stated as "air-fuel feed"), which can be delivered to different parts of the intake system together with the charged air. The charged air can be at ambient temperature and pressure at the inlet of the engine system, and the conditions (e.g., temperature, pressure, etc.) can change as the charged air passes through the intake system (e.g., through a turbocharger, aftercooler, intake manifold, etc.) upstream of the location where the fuel is introduced into the system.

[0020] In some embodiments, as described above, the second liquid fuel can be a biofuel and / or a low-carbon fuel. Biofuels and / or low-carbon fuels can also reduce the environmental impact of vehicle operation by reducing particulate matter emissions and carbon dioxide relative to engines that operate using only diesel fuel. Therefore, in some embodiments, emission reduction can be achieved by using biofuels and / or low-carbon fuels. In addition, in the case where biofuels and / or low-carbon fuels are available, biofuels and / or low-carbon fuels can provide a cheaper alternative to diesel. Biofuels and / or low-carbon fuels can also provide energy security in areas where diesel may not be easily available. For example, methanol can be produced from coal rather than crude oil, and therefore can be provided as a feasible alternative to operating using only diesel.

[0021] In some embodiments, the fuel vaporization system is configured to heat the second liquid fuel using waste heat from a heating medium, which may be one or a combination of engine coolant, return fuel (e.g., return first liquid fuel and / or return second liquid fuel), exhaust gas, and / or heated charge air leaving a turbocharger. For example, the fuel vaporization system may include at least one heat exchanger disposed along an air intake system of an engine system to heat the charge air or air-fuel feed (or reduce charge air or air-fuel feed cooling) before supplying the air-fuel feed to the engine. In some embodiments, the heat exchanger may form part of an intake manifold or air intake system of the engine. In other embodiments, the heat exchanger may form part of an intercooler or aftercooler for cooling charge air leaving at least one turbocharger. In other embodiments, the fuel vaporization system includes a passive heating element, such as a grid heater (e.g., a resistive heater, etc.), an infrared heater, a ceramic heater, a cartridge heater, a plate heater, or another form of electric heater for heating charge air, air-fuel feed, and / or a second liquid fuel.

[0022] In some embodiments, the fuel vaporization system is configured to heat the second liquid fuel before injecting the second liquid fuel into the air intake system or the engine. For example, the fuel vaporization system may include a heat exchanger disposed along a fluid supply line for providing the second liquid fuel to one or more fuel injectors.

[0023] In some embodiments, the fuel vaporization system is configured to control the fuel temperature of the second liquid fuel by heating at least a portion of the second fuel injection system for the second liquid fuel. The fuel vaporization system can be configured to maintain the second fuel temperature above the vaporization temperature of the second liquid fuel after the second liquid fuel is injected into the air intake system.

[0024] In other embodiments, such as where heat is supplied to the second liquid fuel after injection, the fuel vaporization system is configured to control the heating of the charge air and / or air-fuel charge based on: (i) the flow rate of the second liquid fuel, and (ii) the fuel type, to ensure that the second liquid fuel is adequately vaporized when introduced into the air intake system and to enhance vaporization of the second liquid fuel between the injection point and the engine. In such embodiments, the fuel vaporization system can be configured to control the temperature of the charge air by controlling the amount of heat (e.g., the flow rate and temperature of the heating medium or cooling medium, etc.) provided to the second liquid fuel that exits the second fuel injection system and enters the charge air or the charge air further downstream than the injection point.

[0025] Among other benefits, the engine system, fuel vaporization system, and heating method described herein can enable the injection of a secondary fuel into the air intake system upstream of the engine in a position that allows the modification of an existing diesel fuel engine system to enable operation using a variety of fuels. The fuel vaporization system can enhance the vaporization of the second liquid fuel by, for example, ensuring that the second liquid fuel is heated to above its boiling point (e.g., dew point temperature, etc.) and / or ensuring that sufficient heat is provided to the second liquid fuel to substantially prevent the second liquid fuel from condensing in the intake system (e.g., wall wetting, etc.), which can improve combustion characteristics and / or engine performance. Such a system can also reduce the operating costs associated with the engine system by being able to use low-cost and readily available electronic fuels (such as methanol) and other biofuels. The use of biofuels can also reduce greenhouse gas emissions from the engine system while being able to use 100% diesel fuel when necessary (e.g., during cold start or when biodiesel is not available).

[0026] The various concepts introduced above and discussed in more detail below can be implemented in any of numerous ways, as the concepts described are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0027] The various numerical values ​​provided herein are for reference purposes only. Unless otherwise indicated, all numerals used in this specification and claims to represent the quantity of properties, parameters, conditions, etc. should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximate values. Any numerical parameter should at least be interpreted according to the reported significant digits and by applying ordinary rounding techniques. The term "approximately" when used before a numerical designation, such as a quantity and / or an amount including a range, can vary (+) or (-) 10%, 5% or 1% approximate value.

[0028] As will be understood by those skilled in the art, for any and all purposes, particularly in providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any enumerated range can be easily considered to fully describe and enable the same range to be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be easily divided into lower thirds, middle thirds, and upper thirds, etc. As will be understood by those skilled in the art, all languages ​​such as "up to", "at least", "greater than", "less than", etc. include the cited numbers and refer to the ranges that can be subsequently divided into subranges as discussed above. Finally, as will be understood by those skilled in the art, ranges include each individual member.

[0029] refer to Figure 1 , shows a schematic diagram of an internal combustion engine system 100 (e.g., a dual-fuel engine system, etc.) with multiple secondary fuel injection options according to an embodiment. The engine system 100 includes: an intake manifold 112, the intake manifold 112 being configured to receive charge air 111; a first fuel injection system 122, the first fuel injection system 122 being configured to inject a first liquid fuel 105 into the engine 102; a second fuel injection system 124, the second fuel injection system 124 being configured to inject a second liquid fuel 107 into the charge air 111, the second liquid fuel 107 being different from the first liquid fuel 105; and a fuel vaporization system 103, the fuel vaporization system 103 being configured to heat at least one of (i) the charge air 111 or (ii) the second liquid fuel 107 upstream of the location where the second liquid fuel 107 is injected into the charge air 111 to enhance vaporization of the second liquid fuel 107 and / or improve combustion characteristics of the engine.

[0030] As used herein, "combustion characteristics" refers to characteristics associated with the combustion process occurring in an internal combustion engine. The combustion characteristics may include combustion temperature within the combustion cylinders of the internal combustion engine system 100, the generation of nitrogen oxides (NOx) and / or soot, combustion efficiency, the amount of harmful environmental byproducts produced by the combustion process, and / or other parameters associated with the combustion process.

[0031] The engine system 100 includes an engine 102 (e.g., a long cylinder block including an engine block, pistons, cylinder heads, valve train, etc.). The engine system 100 also includes a first fuel injection system 122 configured to inject a first liquid fuel 105 into the engine 102. The engine system 100 additionally includes a second fuel injection system 124 configured to inject a second liquid fuel 107 into the engine 102. In various embodiments, the second liquid fuel 107 is different from the first liquid fuel 105. The engine system 100 also includes a fuel vaporization system 103 configured to heat at least one of the charge air 111 or the second liquid fuel 107 upstream of the location where the second liquid fuel 107 is injected into the charge air 111, the air intake system, or the engine 102 to enhance vaporization of the second liquid fuel 107. In some embodiments, the fuel vaporization system 103 may form part of an air intake system 115 for the engine system 100 (eg, the intake manifold 112 , an air handling system upstream of the engine 102 and configured to deliver air from the environment surrounding the engine system 100 to the engine 102 , etc.).

[0032] exist Figure 1 In the embodiment of the present invention, the engine system 100 also includes a first-stage turbocharger, shown as a first turbocharger 104; a first aftercooler 106 (e.g., an intercooler, etc.); a second-stage turbocharger, shown as a second turbocharger 108; and a second aftercooler 110. In other embodiments, the engine system 100 may include additional or fewer turbochargers and aftercoolers. In various embodiments, the engine system 100 may include at least one supercharger instead of or in addition to a turbocharger.

[0033] In various embodiments, the engine 102 (e.g., a diesel cycle engine, a spark ignition engine, etc.) can be configured as a dual-fuel engine that is configured to operate using a first liquid fuel 105 and a second liquid fuel 107. More specifically, a dual-fuel engine is an engine that is configured to use a first liquid fuel 105 (e.g., a primary fuel, etc.) from a first fuel source (e.g., a liquid fuel such as diesel fuel) and a second liquid fuel 107 (e.g., a secondary fuel, etc.) from a second fuel source (e.g., a liquid biofuel, etc.). As used herein, "liquid fuel" refers to a fuel that is provided to the engine system 100 in liquid form at atmospheric temperature, but other fuels may also be provided to the engine system 100 in liquid form depending on the pressure and temperature of the fuel system, and all such liquid fuels should also be considered to fall within the scope of the present disclosure.

[0034] In some embodiments, the first liquid fuel 105 and the second liquid fuel 107 have different properties, such as different autoignition temperatures, flame speeds, etc. In some embodiments, the first liquid fuel 105 is diesel fuel. The second liquid fuel 107 can be, for example, an electronic fuel or a liquid biofuel, such as methanol and ethanol. In various embodiments, the first liquid fuel 105 or the second liquid fuel 107 can be any of the following: a high cetane fuel, such as diesel, natural gas synthesis (GTL) diesel, heavy fuel oil (HFO), low sulfur fuel oil (LFSO), hydrogenated vegetable oil (HVO), light diesel (MGO), renewable diesel, biodiesel, paraffinic diesel, dimethyl ether (DME), F-76 fuel, F-34 fuel, Jet A fuel, JP-4 fuel, JP-8 fuel or oxymethylene ether (OME); or a low cetane fuel (e.g., high octane fuel, high methane fuel), such as natural gas, hydrogen, ethane, propane, butane, synthesis gas (syngas), ammonia, methanol, ethanol or gasoline. In various embodiments, the first liquid fuel 105 and / or the second liquid fuel 107 may be a blend of fuels. However, as discussed in further detail herein, the foregoing are merely examples of fuels and do not exclude other types of first and second liquid fuels.

[0035] The first liquid fuel 105 and the second liquid fuel 107 can be combined in a blend, which is a mixture containing these two fuels. In some embodiments, the first liquid fuel 105 and the second liquid fuel 107 are delivered via a separate mechanism. For example, the first liquid fuel 105 can be delivered to the combustion cylinder 118 of the engine 102 via direct injection, and the second liquid fuel 107 can be delivered via different introduction points (such as the second injector in the combustion cylinder 118 or via the port injector in the intake manifold 112). In some embodiments, the engine 102 is configured to receive a mixture of the first liquid fuel 105 and the second liquid fuel 107, and is configured to determine whether to adjust one or more of a plurality of operating parameters, such as a fuel composition corresponding to the ratio of the first liquid fuel 105 to the second liquid fuel 107 in the fuel mixture. In some embodiments, the ratio of the fuel is adjusted to obtain a target combustion performance.

[0036] In some embodiments, the engine 102 is configured to be arranged in a V-shaped cylinder block. In other embodiments, the engine 102 is an in-line engine or another engine configuration. In some embodiments, the engine 102 is a 4-stroke engine. In other embodiments, the engine is a 2-stroke engine. In various embodiments, the engine 102 is configured to be a high horsepower (HHP) engine, for example, such as an engine capable of providing power in the range of 500hp to 4,500hp or more. The engine system 100 may be configured to provide power to a generator (e.g., a generator set, etc.), an alternator, etc. for generating electricity (e.g., power). In one embodiment, the engine 102 is coupled to the generator, for example, by a drive shaft (not shown). In other embodiments, the engine system 100 may be used for marine applications (e.g., powering a vessel), mining applications (e.g., powering a haul truck and / or an excavator), or railway applications (e.g., powering a locomotive). In other embodiments, the engine system 100 may be used to provide power for another type of vehicle (e.g., a road or off-road vehicle). In still other embodiments, engine system 100 may be used in industrial applications to drive a pump, a hydraulic system, or another type of system.

[0037] The first fuel injection system 122 is configured to supply the first liquid fuel 105 to the engine 102. The first fuel injection system 122 may include a first fuel source, which may be, for example, a first fuel tank that may be configured to receive the first liquid fuel 105. In some embodiments, the first fuel injection system 122 includes a fuel pump or another type of liquid driver that transfers the first liquid fuel 105 from the first fuel tank to the engine or a pressurized fuel rail on the engine. In at least one embodiment, the first fuel injection system 122 includes at least one first liquid fuel injector 126a-126c (collectively referred to as the first liquid fuel injector 126), which is configured to inject fuel directly into the combustion cylinder 118 of the engine 102. The first liquid fuel injector 126 may be a main fuel injector. In some embodiments, the first liquid fuel injector 126 includes a nozzle that is configured to atomize the first liquid fuel 105 and promote mixing of the first liquid fuel 105 in the combustion cylinder 118.

[0038] In some embodiments, the second fuel injection system 124 is arranged similarly to the first fuel injection system 122. The second fuel injection system 124 may include a second fuel source, which may be, for example, a second fuel tank configured to receive the second liquid fuel 107. In some embodiments, the second fuel injection system 124 includes a fuel pump or another type of liquid driver that transfers the second liquid fuel 107 from the second fuel tank to the engine 102. In various embodiments, the second fuel injection system 124 also includes at least one second liquid fuel injector 128a-128h (collectively referred to as the second liquid fuel injector 128). The second liquid fuel injector 128 may be a secondary fuel injector that is configured to inject the second liquid fuel 107 and / or atomize at least a portion of the second liquid fuel 107 when injected. It should be understood that in various embodiments, the second fuel injection system 124 also includes a heater to heat the secondary fuel upstream, downstream, or at a location thereof, of each second liquid fuel injector 128.

[0039] In some embodiments, the second fuel injection system 124 is configured to inject the second liquid fuel 107 upstream of the engine 102 or otherwise provide the second liquid fuel 107. For example, the second fuel injection system 124 may include a first injector 128a disposed upstream of the air intake system, such as upstream of the first turbocharger 104. In some embodiments, the second fuel injection system 124 includes an injector (shown as a second injector 128b and a fourth injector 128d, respectively) disposed at the outlet of the first turbocharger 104 and / or the second turbocharger 108. In other embodiments, the second fuel injection system 124 includes an injector (shown as a third injector 128c and / or a fifth injector 128e, respectively) disposed at the outlet of the first aftercooler 106 and / or the second aftercooler 110.

[0040] In some embodiments, the second fuel injection system 124 includes a sixth injector 128f configured to inject or otherwise provide the second liquid fuel 107 to the engine 102 through the intake manifold 112, such as through port injection, for example, through at least one port along the intake manifold 112. In some embodiments, the second fuel injection system 124 includes a seventh injector 128g disposed at a location proximate to the combustion cylinder 118, such as within at least one intake port 120 of the engine 102 extending between the intake manifold 112 and the combustion cylinder 118.

[0041] In some embodiments, the second fuel injection system 124 is configured to inject or otherwise provide the second liquid fuel 107 directly into the combustion cylinder 118. For example, the second fuel injection system 124 may include an eighth injector 128h arranged to inject or otherwise provide the second liquid fuel 107 directly into the combustion cylinder 118. In such embodiments, as will be further described, the fuel vaporization system 103 is configured to heat the second liquid fuel 107 upstream of the location where the second liquid fuel 107 is injected into the combustion cylinder 118.

[0042] The fuel vaporization system 103 is configured to promote vaporization of the second liquid fuel 107 and prevent the second liquid fuel from condensing upstream of the engine 102. The fuel vaporization system 103 includes at least one heating device, such as an active heater or a heat exchanger. In some embodiments, the fuel vaporization system 103 is configured to use an existing heat exchanger that is part of the air intake system. For example, the fuel vaporization system 103 can use the first aftercooler 106 and / or the second aftercooler 110 to heat the charge air 111 upstream and / or downstream of the location where the second liquid fuel 107 is injected into the engine system 100 (e.g., injected into the charge air 111). For example, the first aftercooler 106 can be used to heat the first compressed charge air 111 entering the first aftercooler 106. The second aftercooler 110 can be used to heat the second compressed charge air 111 entering the second aftercooler 110. In other embodiments, the fuel vaporization system 103 is configured to heat the charge air 111 both upstream and downstream of the location at which the second liquid fuel 107 is injected into the charge air 111 .

[0043] In some embodiments, and as will be referred to Figure 5 to Figure 6 As further described, the fuel vaporization system 103 includes a controller that is communicatively coupled to the first aftercooler 106 and / or the second aftercooler 110, such as a flow control device (e.g., a pump, a valve, etc.) of the first aftercooler 106 and / or the second aftercooler 110, and / or a heating element associated with the first aftercooler 106 and / or the second aftercooler 110. The controller can be configured to control the operation of the first aftercooler 106 and / or the second aftercooler 110 (e.g., the flow control device and / or the heating element, etc.) based on a fuel condition of the second liquid fuel (e.g., based on sensor data indicating a temperature of the second liquid fuel, based on fuel data about the second liquid fuel stored in a memory and / or another fuel condition of the second liquid fuel, etc.) to control the heating of the charge air 111 and / or the air-fuel feed 113 including the second liquid fuel (see Figure 1 ).

[0044] The first aftercooler 106 and / or the second aftercooler 110 may include a heat exchanger that utilizes an engine coolant (e.g., a low-temperature engine coolant, a high-temperature engine coolant, etc.) to cool the charge air 111. In other embodiments, the first aftercooler 106 and / or the second aftercooler 110 include a forced air heat exchanger configured to transfer heat from the charge air 111 to air at ambient temperature flowing through the heat exchanger.

[0045] It should be understood that other heating devices can be used in place of the first aftercooler 106 and / or the second aftercooler 110, or in combination with the first aftercooler 106 and / or the second aftercooler 110, to heat the charge air 111 and / or the air-fuel charge generated by introducing the second liquid fuel 107 into the charge air 111. For example, the engine system 100 may include a heat exchanger that uses engine waste heat to increase the temperature of the charge air 111 and / or the air-fuel charge. The waste heat can be provided by a heating medium. For example, the waste heat can be provided by lubricating oil for lubricating the engine 102, exhaust gas, return fuel from the engine 102 and / or bypass fuel (including the first return liquid fuel and / or the second return liquid fuel from the fuel bypass circuit), or another engine coolant and / or lubricant.

[0046] In some embodiments, the fuel vaporization system 103 may be configured to control one or a combination of: a flow rate of the heating medium through the at least one heat exchanger and / or a temperature of the heating medium.

[0047] In some embodiments, the engine system 100 also includes at least one heat exchanger bypass circuit 130. The heat exchanger bypass circuit 130 may include a heat exchanger bypass valve 131 configured to control an amount of bypass across the at least one heat exchanger, which may reduce an amount of cooling provided by the at least one heat exchanger to the charge air 111 and / or the air-fuel charge.

[0048] Alternatively or in combination, the engine system 100 may include an active heater, such as a grid heater (e.g., a resistive heater, etc.), an infrared heater, a ceramic heater, a cartridge heater, or another form of electrical heater to heat the charge air 111 and / or the air-fuel charge. The active heater may be applied to a wall (e.g., a surface) of the flow conduit and / or directly to various components of the engine system 100. In some embodiments, the active heater is applied to a fluid supply line for the second liquid fuel 107 and / or to a connection between the adjacent injector 128 and the air intake system. In some embodiments, the active heater is applied to a surface of the air intake system adjacent to the location where the second liquid fuel is delivered to the air intake system, such that the fuel vaporization system 103 includes at least one heated surface downstream of the location where the second liquid fuel is delivered to the charge air 111 (see, e.g., FIG. 1 ). Figure 4). The heating surface may be defined, for example, by a heated wall of the intake manifold or another heated wall or wall portion along the air intake system. The fuel vaporization system 103 may be configured to selectively control operation of the active heater (e.g., selectively control operation of the active heater between an on state and an off state, an amount of current supplied to the electric heater, etc.) based on a temperature of the charge air 111, the air-fuel feed, and / or the second liquid fuel 107 (upstream of a location where the second liquid fuel 107 is injected into the air intake system).

[0049] In various embodiments, the heat exchanger is configured to selectively reduce the cooling provided to the charge air 111 and / or the air-fuel charge when the engine 102 is operating in a dual fuel mode, such as when both the first liquid fuel 105 and the second liquid fuel 107 are provided to the engine 102. In some embodiments, the fuel vaporization system 103 is configured to control the cooling provided by the heat exchanger to ensure that the second liquid fuel 107 is fully vaporized while preventing additional heating that may reduce engine performance, as will be further described.

[0050] It should be appreciated that different methods may be used to heat the charge air 111, the air-fuel charge, and / or the second liquid fuel 107. In some embodiments, the fuel vaporization system 103 is configured to heat the charge air 111 upstream of where the second liquid fuel 107 is delivered to the charge air 111 (e.g., the intake manifold, the engine 102, etc.). In other embodiments, the fuel vaporization system 103 is configured to heat the charge air 111 (or reduce cooling provided to the charge air 111) downstream of where the second liquid fuel 107 is delivered to the charge air 111 (e.g., the intake manifold, the engine 102, etc.). In still other embodiments, the fuel vaporization system 103 is configured to heat the second liquid fuel 107 upstream of where the second liquid fuel 107 is delivered to the charge air 111 (e.g., the intake manifold, the engine 102, etc.).

[0051] In one embodiment, the fuel vaporization system 103 is configured to control the operation of the first turbocharger 104 and / or the second turbocharger 108 to selectively increase the temperature of the pressurized air 111 exiting the turbochargers during operation. For example, and as will be described with reference to Figure 5 to Figure 6 Described in more detail, the fuel vaporization system 103 may include a controller communicatively coupled to the turbocharger. The controller may be configured to control the operation of the turbocharger based on a fuel condition of the second liquid fuel (e.g., based on sensor data indicating a temperature of the second liquid fuel, based on fuel data about the second liquid fuel stored in a memory, etc. and / or another fuel condition of the second liquid fuel, etc.) to control the heating of the charge air 111.

[0052] For example, the turbocharger may be a variable geometry turbocharger that enables the turbocharger's operating point and the turbocharger's aerodynamic efficiency to be varied to vary the amount of heat provided to the charge air (e.g., provided to the first charge air entering the first turbocharger 104, provided to the second charge air entering the second turbocharger 108, etc.). In some embodiments, the engine system 100 and / or the turbocharger include an exhaust throttle to increase flow restriction downstream of the turbocharger. By controlling the turbocharger's geometry and / or the flow resistance downstream of the turbocharger, the fuel vaporization system 103 may operate the turbocharger at a less efficient operating point, resulting in a greater increase in temperature across the turbocharger.

[0053] In some embodiments, such as in Figure 1 As reflected in FIG. 1 , the engine system 100 includes at least one compressor bypass circuit 132 extending between an outlet of at least one of the turbochargers (e.g., a compressor of the turbocharger) and an inlet of the at least one turbocharger. The compressor bypass circuit 132 may be configured (e.g., based on a position of a compressor bypass valve 134) to recirculate a portion of the pressurized air 111 and / or air-fuel charge passing through the turbocharger, thereby increasing the total flow rate through the turbocharger and the temperature of the fluid entering the turbocharger without increasing the flow rate of the pressurized air 111 entering the engine 102.

[0054] In various embodiments, the fuel vaporization system 103 is configured to control the flow rate of engine coolant through the engine 102 to regulate the temperature of the air-fuel charge entering the combustion cylinders 118. For example, the fuel vaporization system 103 can be configured to control the flow rate of engine coolant through at least one water jacket 136a-136c of a cylinder head of the engine 102 and / or through other portions of the engine 102 to control the temperature of the air-fuel charge.

[0055] In some embodiments, the engine system 100 is configured to recirculate hot exhaust gas to heat the charge air 111 and / or the air-fuel charge. Figure 2 , another example engine system 200 including an exhaust gas recirculation (EGR) system is shown. The EGR system includes at least one recirculation loop 222a-222e (collectively referred to as recirculation loop 222) configured to recirculate exhaust gas 223 back to the charge air and / or air-fuel charge to increase the temperature of the charge air and / or air-fuel charge. Figure 2The location of the recirculation loop 222 in FIG. 1 is provided for illustrative purposes only, and it should be understood that various modifications are possible without departing from the inventive principles disclosed herein. For example, in some embodiments, the EGR system may also include a bypass loop around one or more heat exchangers and / or compressors, such as with respect to FIG. Figure 1 (e.g., at least one heat exchanger bypass loop 130, at least one compressor bypass loop 132, etc.) Additionally, in various embodiments, the EGR system further includes a bypass valve in at least one recirculation loop 222 that allows the system to selectively control the temperature of the charge air entering the intake manifold.

[0056] For example, the engine system 200 may include: (i) a first recirculation loop 222a extending between an outlet of a first turbine 218 of a first turbocharger and an inlet of a first compressor 204 of the first turbocharger; (ii) a second recirculation loop 222b extending between an inlet of the first turbine 218 and an outlet of the first compressor 204; (iii) a third recirculation loop 222c extending between an inlet of the first turbine 218 and an outlet of a first aftercooler 206 located between the first turbocharger and the second turbocharger; (iv) a fourth recirculation loop 222d extending between an inlet of a second turbine 216 of a second turbocharger (e.g., between the exhaust manifold 214 and the second turbine 216) and an outlet of the second compressor 208 of the second turbocharger; and / or (v) a fifth recirculation loop 222e extending between an inlet of the second turbine 216 and an outlet of the second aftercooler 210 (between the second aftercooler 210 and the intake manifold 212).

[0057] In some embodiments, the recirculation loop 222 includes at least one recirculation loop valve 224 that can be controlled by the fuel vaporization system 103 to control the flow rate of exhaust gas through the EGR system. Figure 5 to Figure 6 As further described, the fuel vaporization system 103 may include a controller communicatively coupled to the recirculation loop valve 224. The controller may be configured to control operation of the recirculation loop 222 (e.g., the recirculation loop valve 224, etc.) based on a fuel condition of the second liquid fuel (e.g., based on sensor data indicating a temperature of the second liquid fuel, based on fuel data regarding the second liquid fuel stored in memory and / or another fuel condition of the second liquid fuel, etc.) to control heating of the charge air 111 and / or the air-fuel charge.

[0058] In various embodiments, as described above, at least one component of the engine system is configured to form a heat exchanger to recover waste heat from the engine system. Figure 3, an example engine system 300 is shown including an intake manifold 312 that forms part of a crossflow heat exchanger for the engine system 300 .

[0059] The intake manifold 312 includes a double wall including an inner wall 314 and an outer wall 316 that together define a cooling passage 318. The fuel vaporization system can be configured to control the flow rate and / or temperature of a heating medium 320 passing through the cooling passage 318 to control the heating of the inner wall 314 and the air-fuel charge moving toward the combustion cylinders through the intake manifold 312. The heating medium can include at least one of: a return fuel, a coolant, a dedicated heating fluid, and / or an additional heat transfer fluid. It should be understood that other components of the engine system 300 may also be adapted to form a portion of a waste heat exchanger for the engine system 300.

[0060] In various embodiments, as described above, the engine system can be configured to preheat the second liquid fuel before providing the second liquid fuel to the air intake system and / or the engine. Figure 4 , shows an example second fuel injection system 400 that is configured to preheat a second liquid fuel prior to injection.

[0061] The second fuel injection system 400 includes a second fuel source, which can be, for example, a second fuel tank 402 configured to receive a second liquid fuel 404. In some embodiments, the second fuel injection system 400 includes a fuel pump 406 or another type of liquid driver that transfers the second liquid fuel 404 from the second fuel tank 402 to the engine (e.g., to the intake manifold and / or other components of the air intake system of the engine). The second fuel injection system 400 also includes at least one second liquid fuel injector 428a-428h (collectively referred to as second liquid fuel injector 428). The second liquid fuel injector 428 can be a secondary fuel injector that is configured to inject the second liquid fuel 404 and / or atomize at least a portion of the second liquid fuel 404 when injected.

[0062] In some embodiments, the second fuel injection system 400 includes a control valve 408 and / or a thermostat configured to control flow resistance downstream of the fuel pump 406. The fuel vaporization system can be configured to control the control valve 408 and / or the thermostat to control the temperature of the second liquid fuel 404 exiting the second fuel injection system 400.

[0063] In some embodiments, the second fuel injection system 400 includes at least one heat exchanger 410 and / or at least one active heater 412 to enable the fuel vaporization system to control the temperature of the second liquid fuel 404. The second fuel injection system 400 may also include any of the various heating devices described herein to enable heating of the second liquid fuel prior to injection.

[0064] In some embodiments, as shown in reference Figure 1 As described, the fuel vaporization system includes a heating surface defined by a heated wall and / or wall portion of the air intake system. Figure 4 As shown, the fuel vaporization system can include a heating surface 429 positioned adjacent to where the second liquid fuel is delivered to the air intake system. In such an embodiment, the second fuel injection system 400 can be arranged to inject the second liquid fuel toward the heating surface 429 to control the temperature of the second liquid fuel and promote vaporization. In some embodiments, the fuel vaporization system includes an active heater that is thermally coupled to the heating surface and is configured to control the heating of the heating surface 429 based on a fuel condition of the second liquid fuel (e.g., based on sensor data indicating a temperature of the second liquid fuel, based on fuel data about the second liquid fuel stored in a memory and / or another fuel condition of the second liquid fuel, etc.).

[0065] refer to Figure 5 , shows a control system 500 for a fuel vaporization system according to an embodiment. The fuel vaporization system (e.g., control system 500) includes a heating system 522, a sensor 518, and a controller 502. The heating system 522 is configured to be coupled to an engine or a fuel injection system of a dual-fuel engine system that is configured to operate using a combination of a first liquid fuel and a second liquid fuel. The heating system 522 is configured to control the heating of the second liquid fuel. The sensor 518 is configured to generate sensor data indicating a fuel condition of the second liquid fuel. The controller 502 is communicatively coupled to the heating system 522 and the sensor 518. The controller 502 is configured to receive sensor data from the sensor 518, and based on the fuel condition, control the operation of the heating system 522 to heat the second liquid fuel before the second liquid fuel is injected into the engine to enhance vaporization of the second liquid fuel and / or improve the combustion characteristics of the engine.

[0066] The control system 500 includes a controller 502. The controller 502 (eg, a control unit, etc.) is configured to interpret data from various sensors disposed within the engine system and control various components of the engine system based on the data.

[0067] The controller 502 may be configured as one or more electronic control units (ECUs). In some embodiments, the controller 502 includes a plurality of sub-controllers. In other embodiments, the controller 502 is a distributed controller. Therefore, the controller 502 may be separate from or included with at least one engine control unit in an engine control unit for an engine system.

[0068] In various embodiments, the controller 502 includes a processing circuit 504 having a processor 506 and a memory 508. In some embodiments, the controller 502 also includes various control circuits to coordinate the operation of the fuel vaporization system. For example, the controller 502 may include a feed monitoring circuit 510, a heating device monitoring circuit 512, and / or a heating (or cooling reduction) control circuit 514. In some embodiments, the controller 502 additionally includes a communication interface 516 that communicatively couples the controller 502 to various other components of the engine system.

[0069] In one configuration, the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514 are configured by a computer-readable medium that can be executed by a processor (such as processor 506). As described herein and in other uses, the circuit facilitates the execution of certain operations to achieve the reception and transmission of data. For example, the circuit can provide instructions (e.g., commands, etc.) to, for example, collect data. In this regard, the circuit can include programmable logic that defines the acquisition frequency of the data and / or other aspects of the data transmission. In particular, the circuit can be implemented by a computer-readable medium, which can include code written in any programming language, including but not limited to Java, JavaScript, Python, etc. and any conventional process programming language, such as "C" programming language or similar programming language. The computer-readable program code can be executed on one processor or multiple remote processors. In the latter case, the remote processors can be connected to each other through any type of network (e.g., controller area network (CAN) bus, etc.).

[0070] In another configuration, the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514 are implemented as a hardware unit, such as an electronic control unit. Therefore, the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514 can be implemented as one or more circuit components, including but not limited to processing circuits, network interfaces, peripheral devices, input devices, output devices, sensors, etc.

[0071] In some embodiments, the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514 may take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (ICs), discrete circuits, system-on-chip (SOC) circuits, microcontrollers, etc.), telecommunications circuits, hybrid circuits, and any other type of "circuitry". In this regard, the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514 may include any type of components for implementing or facilitating the operations described herein. For example, the circuits described herein may include one or more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, and the like.

[0072] The feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514 may also include programmable hardware devices, such as field programmable gate arrays, programmable array logic, programmable logic devices, etc. In this regard, the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514 may include one or more memory devices for storing instructions that can be executed by a processor of the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514. The one or more memory devices and the processor may have the same definitions as provided below with respect to the memory 508 and the processor 506. Therefore, in this hardware unit configuration, the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the heating control circuit 514 can be dispersed in separate locations throughout the engine system (e.g., as separate control units, etc.). Alternatively, and as in Figure 5 As reflected in , the feed monitoring circuit 510 , the heating device monitoring circuit 512 , and / or the heating control circuit 514 may be implemented in or within a single unit / housing, which is shown as controller 502 .

[0073] In the example shown, the processing circuit 504 can be configured to execute or implement the instructions, commands, and / or control processes described herein with respect to the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514. Thus, the depicted configuration represents the above-described arrangement, wherein the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514 are implemented as a machine or computer readable medium. However, as described above, this illustration is not meant to be limiting, as the present disclosure contemplates other embodiments, such as the aforementioned embodiments, wherein the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514, or at least one of the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514 is configured as a hardware unit. All such combinations and variations are intended to fall within the scope of the present disclosure.

[0074] The processor 506 may be implemented as one or more general purpose processors, application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), digital signal processors (DSPs), a group of processing components, or other suitable electronic processing components. In some embodiments, the processor 506 is shared by multiple circuits (e.g., the feed monitoring circuit 510, the heating device monitoring circuit 512, and / or the heating control circuit 514 may include or otherwise share the same processor 506, which in some example embodiments may execute instructions stored or otherwise accessed via different areas of the memory 508).

[0075] Alternatively or in combination, processor 506 can be one of a plurality of processors configured to perform certain operations independently of one or more coprocessors or to perform certain operations in other ways. In other example embodiments, two or more processors can be connected via a bus to achieve independent, parallel, pipelined or multi-threaded instruction execution. All of these variations are intended to fall within the scope of the present disclosure.

[0076] Memory 508 (e.g., RAM, ROM, flash memory, hard disk storage, etc.) can store data and / or computer code to facilitate the various processes described herein. Memory 508 can be communicatively connected to processor 506 to provide computer code or instructions to processor 506 for performing at least some of the processes described herein. In addition, memory 508 can be or include tangible non-transient volatile memory or non-volatile memory. Therefore, memory 508 can include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein.

[0077] The communication interface 516 may include a wired and / or wireless interface (e.g., jacks, antennas, transmitters, receivers, transceivers, wired terminals, etc.) for communicating data with various components of the engine system. For example, the communication interface 516 may include an Ethernet card and port for sending and receiving data via an Ethernet-based communication network and / or a Wi-Fi transceiver for communicating via a wireless communication network. The communication interface 516 may be configured to communicate via a local area network or a wide area network (e.g., the Internet, etc.), and may use various communication protocols (e.g., IP, local area network (LAN), controller area network (CAN), J1939, local interconnect network (LIN), Bluetooth, ZigBee, radio, cellular, near field communication, etc.).

[0078] The communication interface 516 of the controller 502 is configured to facilitate communication between the controller 502 and various components of the engine system. Figure 5 , the communication interface 516 is configured to coordinate the transmission and reception of data between the controller 502, at least one sensor 518, a human-machine interface (shown as an operator input / output (I / O) 520), and a component of an engine system configured to achieve controlled heating of a second liquid fuel (shown as a heating system 522).

[0079] The feed monitoring circuit 510 is configured to monitor fluid conditions of one or a combination of charge air, air-fuel feed, and / or a second liquid fuel. In some embodiments, the feed monitoring circuit 510 is configured to receive sensor data from at least one sensor 518 and determine the fluid conditions based on the sensor data.

[0080] In some embodiments, the sensor data indicates fluid conditions. For example, the sensor data may indicate the flow rate (e.g., volume flow rate, mass flow rate, etc.) of the pressurized air, the air-fuel feed, and / or the second liquid fuel. In other embodiments, the sensor data may indicate the temperature or pressure of the pressurized air, the air-fuel feed, and / or the second liquid fuel. In at least one embodiment, the sensors 518 are positioned in different areas of the engine system to determine changes in fluid conditions during system operation.

[0081] In still other embodiments, the sensor data indicates the composition of the air-fuel mixture. For example, the sensor data may indicate a substitution rate of the second liquid fuel, a fueling rate of the first liquid fuel, a fueling rate of the second liquid fuel, or another parameter indicating the composition of the mixed fuel.

[0082] In some embodiments, feed monitoring circuit 510 is configured to receive an indication of one or more operating parameters of the engine system based on input to operator I / O 520 .

[0083] In some embodiments, the feed monitoring circuit 510 is configured to determine heating requirements and / or feed temperature set points based on fluid conditions and / or input from the operator I / O 520. For example, the feed monitoring circuit 510 may be configured to calculate the feed temperature set point based on the latent heat of vaporization of the injected secondary liquid fuel or from various other fluid properties stored in the memory 508.

[0084] In various embodiments, the heating device monitoring circuit 512 is configured to monitor the fluid condition of the heating medium passing through one or more heat exchangers of the engine system. Alternatively or in combination, the heating device monitoring circuit 512 can be configured to monitor the operating state of a grid heater or another active heating device. In other embodiments, the heating device monitoring circuit 512 can be configured to monitor the surface temperature of one or more components of the engine system, such as a turbocharger operating temperature, a temperature of a wall of an intake manifold, or a temperature of another component.

[0085] In other embodiments, the heating device monitoring circuit 512 is configured to monitor other engine operating parameters indicative of waste heat generated by the engine system. For example, the heating device monitoring circuit 512 can be configured to measure or otherwise determine engine power or another engine operating parameter indicative of waste heat transferred to the heating medium.

[0086] In some embodiments, the heating device monitoring circuit 512 is configured to determine a target flow rate and / or target temperature of the heating medium that meets the heating requirement and / or the feed temperature set point (as determined by the feed monitoring circuit 510), which will be further described.

[0087] The heating control circuit 514 is configured to control the operation of the heating system 522 based on information from the feed monitoring circuit 510, the heating device monitoring circuit 512 and / or the operator I / O 520. The heating control circuit 514 can be configured to selectively control the operation of one or more heating devices. For example, the heating control circuit 514 can be configured to transmit a control signal to one or more control valves to change the flow rate of the engine coolant or other engine fluid through the heat exchanger arranged along the air intake system. In some embodiments, the heating control circuit 514 is configured to control the bypass of the fluid across one or more heat exchangers, or control the recirculation of the fluid through one or more turbochargers. The heating control circuit 514 can also be configured to selectively control the activation and deactivation of one or more active heating devices.

[0088] refer to Figure 6, shows a method 600 of vaporizing a second liquid fuel to facilitate introduction of the second liquid fuel into a dual fuel engine system according to at least one embodiment. The method 600 may utilize reference Figures 1 to 4 Any of the engine systems described and referenced Figure 5 In other embodiments, the method 600 may include additional, fewer, and / or different operations.

[0089] In some embodiments, method 600 includes receiving data indicating a fuel condition of a second liquid fuel for a dual-fuel engine system. The dual-fuel engine system may be configured to operate using a combination of a first liquid fuel and a second liquid fuel. Method 600 may also include controlling operation of a heating system coupled to and / or forming a portion of the dual-fuel engine system based on the fuel condition to heat the second liquid fuel before the second liquid fuel is injected into an engine of the dual-fuel engine system to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

[0090] In some embodiments, optionally, method 600 includes receiving data indicating a fuel condition of the second liquid fuel at operation 602. In some embodiments, operation 602 includes receiving sensor data indicating a fuel condition from a sensor coupled to the dual-fuel engine system and / or coupled to a second fuel injection system configured to inject the second liquid fuel. The sensor data may indicate a temperature of the second liquid fuel, a type of the second liquid fuel, a dew point of the second liquid fuel, or another fuel condition. In other embodiments, operation 602 may include receiving data indicating a fuel condition from a memory of the control system (e.g., reference 604). Figure 5 Memory 508 ) described above retrieves fuel data regarding the second liquid fuel.

[0091] Method 600 includes controlling operation of a heating system coupled to the dual fuel engine system to heat a second liquid fuel using any one or a combination of the processes described in operations 604 , 606 , and 608 .

[0092] In some embodiments, optionally, method 600 includes controlling the operation of a heating system at operation 604 by heating the charge air passing through the air intake system of the dual fuel engine system upstream of the location where the second liquid fuel is delivered to the charge air. In some embodiments, operation 604 includes controlling the feed temperature upstream of the location where the second liquid fuel is injected into the air intake system. In operation 604, the feed temperature is the temperature of the charge air entering the air intake system. Operation 604 may include controlling any one of the heating devices disposed along the air intake system to control the feed temperature (e.g., removing heat from the feed, adding heat to the feed, and / or controlling how much of the feed is cooled by one or more aftercoolers). Operation 604 may include controlling the heating system to heat the second liquid fuel based on fuel conditions, such as to ensure more complete vaporization of the second liquid fuel (e.g., heating to a dew point above the second liquid fuel before injection, etc.).

[0093] In some embodiments, operation 604 includes implementing closed-loop control (e.g., feedback control) to control the feed temperature so as to satisfy the feed temperature set point. As used herein, "satisfy" refers to controlling a measured parameter based on a set point parameter until the desired operating condition is achieved. For example, and depending on the context in which it is used, "satisfy" may refer to a condition in which the feed temperature (or another measured parameter) is one of: less than the feed temperature set point (or another set point value), greater than the feed temperature set point (or another set point value), within a threshold range of the feed temperature set point (or another set point value), or approximately equal to the feed temperature set point (or another set point value). The feed temperature set point may be a fixed set point value stored in a memory of the controller.

[0094] In other embodiments, operation 604 includes determining the feed temperature set point from a lookup table, a calibratable table, or an algorithm based on the type of the second liquid fuel or other sensed parameters or target parameters. For example, operation 604 may include determining the feed temperature set point based on the latent heat of vaporization of the injected second liquid fuel. In such embodiments, operation 604 may include using values ​​from physical or virtual sensors to determine at least one of: the flow rate of the injected second liquid fuel, the feed flow rate of the charge air through the air intake system, the temperature of the upstream charge air, the temperature of the injected second liquid fuel, or other fluid conditions of the second liquid fuel, such as injection pressure, fuel consumption, etc. In still other embodiments, the feed temperature set point may be a user-specified set point value received from an operator I / O.

[0095] For example, operation 604 may include controlling a fuel vaporization system (e.g., a heating system) based on the feed temperature set point so that the feed has sufficient available thermal energy so that after vaporization and / or mixing of the second liquid fuel with the charge air, the final temperature of the air-fuel feed exceeds or otherwise meets the dew point of water and the dew point of the second liquid fuel. In this context, "meets" refers to a condition where the temperature of the air-fuel feed is greater than or exceeds both the dew point of water and the dew point of the second liquid fuel by a certain dew point margin.

[0096] In other embodiments, operation 604 includes controlling the fuel vaporization system so that the feed has sufficient available thermal energy to vaporize the second liquid fuel at a rate that meets the threshold engine performance and / or threshold engine durability. Such a control algorithm may result in a higher or lower feed temperature than the dew point based control operation described above.

[0097] In some embodiments, optionally, method 600 includes controlling a feed temperature downstream of a location where the second liquid fuel is injected into the air intake system (e.g., controlling the temperature of the air-fuel feed) at 606. For example, operation 606 may include controlling a heating system (e.g., heating system 522) to heat the air-fuel feed downstream of a location where the second liquid fuel is injected into the air intake system. In operation 606, the feed temperature is the temperature of the air-fuel feed of a mixture of the second liquid fuel and the charge air. Operation 606 may include controlling any of the heating devices disposed along the air intake system (e.g., a flow control device and / or a heating device associated with an aftercooler, a flow control device associated with a recirculation loop and / or a bypass loop, etc.) to control the temperature of the air-fuel feed (e.g., removing heat from the air-fuel feed, adding heat to the air-fuel feed, and / or controlling how much of the air-fuel feed is cooled by one or more aftercoolers). For example, operation 606 may include controlling a flow rate of a coolant through an aftercooler of the engine system based on the fuel condition of the second liquid fuel.

[0098] In some embodiments, operation 606 includes implementing closed-loop control (eg, feedback control) to control the temperature of the air-fuel charge to meet a final charge temperature set point. The final charge temperature set point may be a fixed set point value stored in a memory of the controller.

[0099] In other embodiments, operation 606 includes determining the final feed temperature set point from a lookup table, a calibratable table, or an algorithm based on other sensed parameters or target parameters, such as a substitution rate, engine power, a fueling rate of the second liquid fuel, a fueling rate of the first liquid fuel, or another known or derived parameter.

[0100] For example, operation 606 may include controlling the fuel vaporization system so that the temperature of the air-fuel feed exceeds the dew point of water and the dew point of the second liquid fuel. In this context, "satisfy" refers to a condition where the temperature of the air-fuel feed is greater than or exceeds both the dew point of water and the dew point of the second liquid fuel by a certain dew point margin.

[0101] In other embodiments, operation 606 includes controlling the fuel vaporization system such that the second liquid fuel vaporizes at a rate that satisfies a threshold performance and / or threshold durability requirement of the engine system.Such a control algorithm may result in higher or lower feed temperatures than the dew point based control operation described above.

[0102] In some embodiments, operation 604 and / or operation 606 include implementing a threshold-based control technique to control the feed temperature upstream and / or downstream of the location where the second liquid fuel is injected. For example, the fuel vaporization system can be configured to control a heating device (e.g., an active heating device and / or a heat exchanger) between an "on" condition and an "off" condition, wherein the heating device is activated in the "on" condition and the heating device is deactivated in the "off" condition.

[0103] For example, operation 604 and / or operation 606 may include switching the device to an “on” condition when the engine system operating condition is less than or equal to a lower threshold, and switching the device to an “off” condition when the engine system operating condition is greater than or equal to an upper threshold.

[0104] In some embodiments, the lower threshold may be a fixed value from memory or based on user input from an operator I / O. For example, the lower threshold may be one or a combination of fluid conditions and / or engine operating conditions that indicate a need to heat the charge air and / or air-fuel charge. In other embodiments, the fuel vaporization system (e.g., a controller) may be configured to determine the lower threshold using a lookup table, a calibratable table, or an algorithm based on any sensed parameter or target parameter that affects or indicates the likelihood of vaporization of the second liquid fuel, such as a substitution rate of the second liquid fuel, engine power, a fueling rate of the second liquid fuel, a fueling rate of the first liquid fuel, or another engine system operating parameter.

[0105] In some embodiments, the fuel vaporization system (e.g., a controller) is configured to calculate the lower threshold based on the latent heat of vaporization of the injected second liquid fuel. For example, operations 604 and / or 606 may include determining the lower threshold using values ​​from physical or virtual sensors for any one or a combination of the following: a flow rate of the injected second liquid fuel, a flow rate of charge air and / or air-fuel charge moving through the air intake system, a temperature of the injected second liquid fuel, and / or other fluid conditions of the second liquid fuel, such as injection pressure, a composition of the second liquid fuel, or other fluid conditions.

[0106] The upper threshold may be a fixed value from memory or based on user input from an operator I / O. In other embodiments, the fuel vaporization system (e.g., a controller) may be configured to determine the upper threshold using a lookup table, a calibratable table, or an algorithm based on any sensed parameter or target parameter. The use of lower and upper thresholds may provide sufficient hysteresis to avoid on / off bounce of valves and other heating devices while achieving performance and durability requirements for the engine system.

[0107] In some embodiments, optionally, method 600 includes, at 608, controlling the temperature of the second liquid fuel at a location before the second liquid fuel is injected into the air intake system. In some embodiments, operation 608 includes implementing closed-loop control (e.g., feedback control) to control the temperature of the second liquid fuel so as to meet the second liquid fuel temperature set point. In one embodiment, operation 608 includes controlling the temperature of the second liquid fuel (e.g., measured by a temperature sensor adjacent to the outlet of the second fuel injection system) to meet the second liquid fuel temperature set point that has been found to facilitate vaporization. In such an embodiment, operation 608 may include determining the second liquid fuel temperature set point based on a lookup table, a calibratable table, or an algorithm. For example, operation 608 may include determining the second liquid fuel temperature set point using a parametric equation for the vaporization temperature from various engine systems or fluid conditions of the second liquid fuel.

[0108] In other embodiments, operation 608 includes raising the temperature of the second liquid fuel to a point where the second liquid fuel has sufficient heat to boil and vaporize when delivered into the charge air flow. In such embodiments, operation 608 may include determining a second energy rate of the second liquid fuel and a first energy rate of the charge air. For example, operation 608 may include determining the second energy rate and the first energy rate based on sensor data from at least one physical or virtual sensor. Operation 608 may include determining a second liquid fuel temperature set point such that the energy difference or ratio between the second energy rate and the first energy rate is high enough that the second liquid fuel will completely vaporize when injected into the charge air.

[0109] In some embodiments, the fuel vaporization system is further configured to control the pressure of the second liquid fuel independently of or in conjunction with the temperature of the second liquid fuel to enable the second liquid fuel to be heated to the second liquid fuel temperature set point. This arrangement can prevent the second liquid fuel in the fuel supply line from boiling before injection.

[0110] Operation 608 may include heating the second liquid fuel by controlling a mass flow rate or a volume flow rate of a heating medium through at least one heating device (e.g., a heat exchanger) using one or a combination of control valves, pump speed control, and / or flow diversion (e.g., fluid bypass across at least one turbocharger, increasing or otherwise controlling EGR, etc.) In some embodiments, operation 608 includes controlling an active heating device to control the amount of heat transferred directly and / or indirectly through the heating medium to the second liquid fuel.

[0111] The heating medium may include a return flow and / or a bypass flow of an engine coolant, a second liquid fuel and / or a first liquid fuel, exhaust gas from the engine, pressurized air, or a combination thereof. The fuel vaporization system may be configured to control the flow rate and / or temperature of the heating medium introduced into at least one heat exchanger along the second fuel injection system. At least one heat exchanger may be sized to increase the temperature of the second liquid fuel without the need for an auxiliary heater. In some embodiments, at least one heat exchanger further includes a thermostat or is fluidly connected to the thermostat, which is configured to regulate the flow of the second liquid fuel and / or the heating medium to prevent an overheating condition that may adversely affect engine performance. In such an embodiment, the fuel vaporization system may operate without using a closed-loop control algorithm or an active controller.

[0112] The present technology may also include, but is not limited to, the features and combinations of these features described in the following lettered paragraphs, and it should be understood that the following paragraphs should not be interpreted as limiting the scope of the appended claims or requiring that all of these features must be included in these claims:

[0113] A. An engine system, comprising:

[0114] an engine including an intake manifold configured to receive charge air;

[0115] a first fuel injection system configured to inject a first liquid fuel into the engine;

[0116] a second fuel injection system configured to inject a second liquid fuel into the charge air, the second liquid fuel being different from the first fuel; and

[0117] A fuel vaporization system is configured to heat at least one of (i) the charge air or (ii) the second liquid fuel upstream of a location where the second liquid fuel is injected into the charge air to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

[0118] B. The engine system of paragraph A, wherein the fuel vaporization system is configured to heat the charge air upstream of a location where the second liquid fuel is delivered to the charge air.

[0119] C. The engine system of paragraph A, wherein the fuel vaporization system is configured to heat the charge air downstream of a location where the second liquid fuel is delivered to the charge air.

[0120] D. The engine system of paragraph A, wherein the fuel vaporization system is configured to heat the second liquid fuel upstream of a location where the second liquid fuel is delivered to the charge air.

[0121] E. The engine system of any of paragraphs A to D, wherein the fuel vaporization system is configured to control heating of the charge air or the second liquid fuel based on at least one of a flow rate or a fuel type of the second liquid fuel.

[0122] F. The engine system of any of paragraphs A to E, wherein the fuel vaporization system is configured to heat the second liquid fuel using waste heat from at least one of engine coolant, return fuel, exhaust gas, or the charge air.

[0123] G. The engine system of paragraph A, wherein the fuel vaporization system includes at least one heating surface downstream of a location where the second liquid fuel is delivered to the charge air.

[0124] H. The engine system of paragraph A, further comprising a turbocharger, wherein the fuel vaporization system comprises a controller configured to control operation of the turbocharger based on a condition of the second liquid fuel to control heating of the charge air.

[0125] I. The engine system of paragraph A, wherein the second fuel injection system is configured to inject the second liquid fuel into the charge air to generate an air-fuel charge, and the fuel vaporization system comprises:

[0126] a recirculation loop configured to recirculate exhaust gas back to the charge air and / or the air-fuel charge; and

[0127] A controller is configured to control operation of the recirculation loop based on a condition of the second liquid fuel.

[0128] J. The engine system of paragraph A, further comprising an aftercooler, wherein the fuel vaporization system includes a controller configured to control operation of the aftercooler based on a condition of the second liquid fuel.

[0129] K. The engine system of any of paragraphs A to J, wherein the first liquid fuel is diesel fuel, and wherein the second liquid fuel is a biofuel.

[0130] L. A fuel vaporization system comprising:

[0131] a heating system configured to be coupled to an engine or a fuel injection system of a dual fuel engine system configured to operate using a combination of a first liquid fuel and a second liquid fuel, the heating system configured to control heating of the second liquid fuel;

[0132] a sensor configured to generate sensor data indicative of a fuel condition of the second liquid fuel; and

[0133] a controller communicatively coupled to the heating system and the sensor, the controller being configured to:

[0134] receiving the sensor data from the sensor; and

[0135] Operation of the heating system is controlled based on the fuel conditions to heat the second liquid fuel before the second liquid fuel is injected into the engine to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

[0136] M. The fuel vaporization system of paragraph L, wherein the controller is further configured to:

[0137] determining a feed temperature set point based on the latent heat of vaporization of the liquid fuel; and

[0138] The heating system is controlled based on the feed temperature set point and the sensor data.

[0139] N. A fuel vaporization system according to paragraph M, wherein the controller is further configured to control the heating system so that the final temperature of the air-fuel charge entering the engine exceeds the dew point of water and the dew point of the second liquid fuel.

[0140] O. A fuel vaporization system according to paragraph L, wherein the heating system includes an aftercooler of the dual-fuel engine system, and wherein the controller is further configured to control a flow rate of a fluid through the aftercooler based on the sensor data.

[0141] P. A fuel vaporization system according to paragraph L, wherein the heating system includes a recirculation loop, which is configured to recirculate exhaust gas back to the air intake system of the dual-fuel engine system, and wherein the controller is also configured to control the flow rate of the exhaust gas through the recirculation loop based on the sensor data.

[0142] Q. The fuel vaporization system of paragraph L, wherein the heating system includes a turbocharger, wherein the controller is further configured to control operation of the turbocharger based on the sensor data.

[0143] R. A method for vaporizing a secondary liquid fuel, the method comprising:

[0144] receiving data indicative of a fuel condition of a second liquid fuel for a dual fuel engine system configured to operate using a combination of a first liquid fuel and a second liquid fuel; and

[0145] Based on the fuel condition, operation of a heating system coupled to the dual-fuel engine system is controlled to heat the second liquid fuel before injecting the second liquid fuel into an engine of the dual-fuel engine system to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

[0146] S. The method of paragraph R, wherein controlling operation of the heating system includes heating the charge air upstream of a location where the second liquid fuel is delivered to the charge air passing through an air intake system of the dual fuel engine system.

[0147] T. The method of paragraph R, wherein controlling operation of the heating system includes heating the charge air downstream of a location where the second liquid fuel is delivered to the charge air passing through an air intake system of the dual fuel engine system.

[0148] It should be noted that the term "exemplary" used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representatives and / or illustrations of possible embodiments (and such terms are not intended to imply that such embodiments are necessarily particular or excellent examples).

[0149] As utilized herein, the term "substantially" and similar terms are intended to have a broad meaning consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of the present disclosure belongs. Those skilled in the art who review the present disclosure should understand that these terms are intended to allow description of certain features described and claimed without limiting the scope of these features to the precise numerical ranges provided. Therefore, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the present invention as described in the appended claims.

[0150] The terms "coupled," "connected," and similar terms as used herein mean the joining of two members directly or indirectly to one another. Such joining may be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved by the two members, or the two members and any additional intermediate members, being integrally formed as a single unitary body with one another or by the two members, or the two members and any additional intermediate members, being attached to one another.

[0151] It is important to note that the structure and arrangement of the various exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in the present disclosure, those skilled in the art who review the present disclosure will readily recognize that many modifications (e.g., changes in the size, dimensions, structure, shape and proportion of the various elements, the values ​​of the parameters, the mounting arrangements, the use of materials, the orientation, etc.) are possible without materially departing from the novel teachings and advantages of the subject matter described herein. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of the embodiments described herein.

[0152] Although this specification contains specific implementation details, these should not be interpreted as limitations on any embodiment or the scope of the content that can be claimed, but rather as descriptions of features peculiar to the specific embodiments of specific embodiments. Certain features described in the context of separate embodiments in this specification may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations, even initially claimed as such, in some cases, one or more features from the claimed combination may be deleted from the combination, and the claimed combination may point to a variant of a sub-combination or a sub-combination.

Claims

1. An engine system, comprising: an engine including an intake manifold configured to receive charge air; a first fuel injection system configured to inject a first liquid fuel into the engine; a second fuel injection system configured to inject a second liquid fuel into the charge air, the second liquid fuel being different from the first liquid fuel; and A fuel vaporization system is configured to heat at least one of (i) the charge air or (ii) the second liquid fuel upstream of a location where the second liquid fuel is injected into the charge air to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

2. The engine system according to claim 1, wherein: The fuel vaporization system is configured to heat the charge air upstream of a location where the second liquid fuel is delivered to the charge air.

3. The engine system according to claim 1, wherein: The fuel vaporization system is configured to heat the charge air downstream of a location where the second liquid fuel is delivered to the charge air.

4. The engine system according to claim 1, wherein: The fuel vaporization system is configured to heat the second liquid fuel upstream of a location where the second liquid fuel is delivered to the charge air.

5. The engine system according to claim 1, wherein: The fuel vaporization system is configured to control heating of the charge air or the second liquid fuel based on at least one of a flow rate or a fuel type of the second liquid fuel.

6. The engine system according to claim 1, wherein: The fuel vaporization system is configured to heat the second liquid fuel using waste heat from at least one of engine coolant, return fuel, exhaust gas, or the charge air.

7. The engine system according to claim 1, wherein: The fuel vaporization system includes a heating surface downstream of a location where the second liquid fuel is delivered to the charge air.

8. The engine system of claim 1 further comprising a turbocharger, wherein: The fuel vaporization system includes a controller configured to control operation of the turbocharger based on a fuel condition of the second liquid fuel to control heating of the charge air.

9. The engine system of claim 1, wherein: The second fuel injection system is configured to inject the second liquid fuel into the charge air to generate an air-fuel charge, the fuel vaporization system comprising: a recirculation loop configured to recirculate exhaust gas back to the charge air and / or the air-fuel charge; and A controller is configured to control operation of the recirculation loop based on a fuel condition of the second liquid fuel.

10. The engine system of claim 1 further comprising an aftercooler, wherein: The fuel vaporization system includes a controller configured to control operation of the aftercooler based on a fuel condition of the second liquid fuel.

11. The engine system of claim 1, wherein: The first liquid fuel is diesel fuel, and wherein the second liquid fuel is a biofuel.

12. A fuel vaporization system comprising: a heating system configured to be coupled to an engine or a fuel injection system of a dual fuel engine system configured to operate using a combination of a first liquid fuel and a second liquid fuel, the heating system configured to control heating of the second liquid fuel; a sensor configured to generate sensor data indicative of a fuel condition of the second liquid fuel; and A controller is communicatively coupled to the heating system and the sensor, the controller being configured to control the operation of the heating system based on the fuel condition to heat the second liquid fuel before the second liquid fuel is injected into the engine to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

13. The fuel vaporization system according to claim 12, wherein: The controller is also configured to: determining a feed temperature set point based on the latent heat of vaporization of the second liquid fuel; and The heating system is controlled based on the feed temperature set point and the sensor data.

14. The fuel vaporization system according to claim 13, wherein: The controller is also configured to control the heating system such that a final temperature of the air-fuel charge entering the engine exceeds a dew point of water and a dew point of the second liquid fuel.

15. The fuel vaporization system of claim 12, wherein: The heating system includes an aftercooler of the dual fuel engine system, and wherein the controller is further configured to control a flow rate of a fluid through the aftercooler based on the sensor data.

16. The fuel vaporization system of claim 12, wherein: The heating system includes a recirculation loop configured to recirculate exhaust gas back to an air intake system of the dual fuel engine system, and wherein the controller is further configured to control a flow rate of the exhaust gas through the recirculation loop based on the sensor data.

17. The fuel vaporization system of claim 12, wherein: The heating system includes a turbocharger, wherein the controller is further configured to control operation of the turbocharger based on the sensor data.

18. A method for vaporizing a secondary liquid fuel, the method comprising: receiving data indicative of a fuel condition of a second liquid fuel for a dual fuel engine system configured to operate using a combination of a first liquid fuel and a second liquid fuel; and Based on the fuel condition, the operation of a heating system of an engine coupled to the dual-fuel engine system or a fuel injection system of the dual-fuel engine system is controlled to heat the second liquid fuel before injecting the second liquid fuel into the engine to enhance vaporization of the second liquid fuel and / or improve combustion characteristics of the engine.

19. The method according to claim 18, wherein: Controlling operation of the heating system includes heating the charge air upstream of a location where the second liquid fuel is delivered to the charge air passing through an air intake system of the dual fuel engine system.

20. The method according to claim 18, wherein: Controlling operation of the heating system includes heating the charge air downstream of a location where the second liquid fuel is delivered to the charge air passing through an air intake system of the dual fuel engine system.

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