System and method for supplying ammonia to a diesel engine

Abstract

A system (100) and method for supplying ammonia to a diesel engine are disclosed. The system (100) comprises a first fluid circuit configured to supply ammonia, an engine (102) including a fuel rail system (104) in fluid communication with the first fluid circuit, a first engine control unit (134) connected to a diesel injector (114) configured to control injection of diesel, and a second engine control unit (136) connected to an ammonia injector (112) and the first engine control unit (134) configured to control injection of ammonia. The system (100) is configured to directly supply ammonia in liquid phase. The first engine control unit (134) and second engine control unit (136) are configured to receive engine parameters and the engine parameters related to ammonia. The first engine control unit (134) is configured to reduce diesel injection and compensate energy through ammonia injection.

Description

SYSTEM AND METHOD FOR SUPPLYING AMMONIA TO A DIESEL ENGINETECHNICAL FIELD

[0001] The present invention generally relates to a fuel injection system. More specifically, the present invention relates to a system and method for supplying ammonia directly into an engine cylinder of a diesel engine.BACKGROUND

[0002] Ammonia (NH3) has gained significant recognition as a carbon-free fuel and is now emerging as a promising candidate for deployment in marine engines. This heightened interest is primarily a response to the global imperative to transition towards cleaner, more sustainable fuels in the transportation sector. This transformative shift is driven by a set of regulations and directives, most notably Directive 2003 / 87 / EC, Decision (EU) 2015 / 1814, and Regulation (EU) 2015 / 757, collectively forming a comprehensive strategy to combat the detrimental impact of human-generated greenhouse gas emissions, with a target to achieve significant reductions by 2050. Simultaneously, recent mandates within the European Union (EU) dictate that all new vehicles entering the EU market from 2035 must produce zero CO2 emissions, which further amplifies the commitment to advancing research and development in the realm of decarbonized fuels.

[0003] Within this overarching framework, hydrogen and ammonia are positioned as key players in the journey towards decarbonizing multiple sectors, including land-based transportation, maritime transport, aviation, and energy-related domains. The core of this decarbonization strategy hinges on harnessing renewable energy sources for the production and storage of green hydrogen or ammonia. To make this strategy feasible and widely accepted, it demands a substantial expansion in renewable energy production capacity to approximately 120,000 TWh by 2050, roughly four to five times the current levels, alongside a considerable reduction in associated costs.

[0004] Ammonia, prized for its efficiency and safety as a hydrogen carrier, has been suggested for utilization in vessel engines. Nevertheless, the intricate nature of ammonia's combustion characteristics necessitates a dual-fuel approach to ensure optimal combustion efficiency and completeness.

[0005] A few existing patent applications have endeavoured to tackle the issues previously outlined, and they are discussed below:

[0006] Luciano Cippitani's US8180556B2, titled "System for Supply of LPG / Ammonia for Direct-Injection Petrol or Diesel Engines," presents a system designed for delivering LPG or ammonia to direct-injection petrol or diesel engines. This system involves an electronic control unit that manages various components, including petrol / diesel pumps, solenoid valves, and injectors, ensuring that only one of LPG / ammonia or petrol / diesel is supplied to the engine at any given moment. However, it's worth noting that Cippitani's reference primarily addresses LPG / ammonia for direct-injection petrol or diesel engines, and it concentrates on resolving operating faults in the system, falling short of providing a simplified solution for ammonia use. Additionally, the system's complexity may pose challenges when integrated with existing setups.

[0007] Uwe Alexander Krug's US8973560, titled "Dual Fuel Supply System for a Direct- Injection System of a Diesel Engine with On-Board Mixing," introduces a dual fuel supply system designed for diesel engines. This system involves a diesel supply component and a mixed fuel supply system that can deliver a premixed liquid fuel combination of diesel and liquefied gaseous fuel to the engine's direct-injection system. It allows for selective switching between the diesel and mixed fuel systems to provide the engine with the desired fuel. However, it is important to note that Krug's reference primarily addresses a dual fuel system that combines diesel with liquefied petroleum gas (LPG) and does not explore the use of ammonia.

[0008] Moreover, these existing references fall short in delivering a comprehensive system and method for achieving significant reductions in both fuel consumption and emissions. The advancements they introduce are not substantial enough to meet the evolving demands of the sustainable energy landscape.

[0009] Hence, there is a clear need for the development of a system and method that integrates diesel ignition with direct ammonia injection, offering a promising pathway to more rapid and thorough combustion processes. This innovation could prove to be a crucial link inachieving the ambitious goals of decarbonizing the transportation and energy sectors while maximizing fuel efficiency and minimizing emissions.SUMMARY

[0010] The present invention discloses a system and method for supplying ammonia to a diesel engine. The system comprises a first fluid circuit configured to supply ammonia. The first fluid circuit comprises an ammonia source configured to store ammonia, a high-pressure pump in fluid communication with the ammonia source configured to deliver ammonia at a desired pressure in liquid phase, and a heater in fluid communication with the high-pressure pump configured to maintain ammonia in the liquid phase. The high-pressure pump is disposed downstream to the ammonia source and upstream to the heater.

[0011] The system further comprises an engine including a fuel rail system in fluid communication with the first fluid circuit. The fuel rail system comprises at least one ammonia injector and at least one diesel injector. The ammonia injector is in fluid communication with the heater. The fuel rail system is configured to directly supply ammonia in liquid phase into engine cylinders via the ammonia injector and supply diesel via the diesel injector.

[0012] The system further comprises one or more engine control units connected to the diesel injector and the ammonia injector. The engine control unit is configured to control injection of diesel and ammonia. The engine control unit is configured to receive engine parameters and the ammonia related parameters. The engine control unit is configured to reduce diesel injection and compensate energy through ammonia injection.

[0013] In one embodiment, the engine control units comprise a first engine control unit connected to the diesel injector configured to control injection of diesel, and a second engine control unit connected to the ammonia injector and the first engine control unit. The second engine control unit is configured to control injection of ammonia. The first engine control unit and second engine control unit are configured to receive engine parameters and the engine parameters related to ammonia. The parameters include intake valve position, engine piston position, engine speed from different sensors installed on the engine, oxygen quantity measured in the exhaust, engine coolant temperature, engine oil temperature, ammonia temperature, ammonia pressure, diesel and ammonia injection duration, injected quantity fuels, time ofinjection of diesel and ammonia, rail pressure for diesel and ammonia, external temperature, intake air temperature, intake air pressure, and exhaust gas pressure and temperature.

[0014] The engine is configured to start to operate with the diesel fuel and the first fluid circuit is configured to supply ammonia when a temperature of a heat exchange fluid at the engine reaches a predefined temperature. The first engine control unit is configured to reduce diesel injection and compensate energy through ammonia injection.

[0015] The first fluid circuit further comprises at least one first valve disposed downstream to the heater, at least one second valve disposed downstream to the first valve, and a mass flow meter disposed downstream to the first valve and upstream to the second valve. The system further comprises an ammonia detector coupled to the first valve. The ammonia detector is configured to detect leakage of ammonia, and the first valve is configured to close on leakage of ammonia exceeding a predefined amount. The second valve is configured to close on detecting backflow of leakage ammonia.

[0016] The first fluid circuit further comprises a low-pressure pump in fluid communication with the engine and the high-pressure pump, and at least one third valve disposed between the low- pressure pump and the engine. The low-pressure pump is disposed downstream to the engine and upstream to the high-pressure pump. The low-pressure pump is configured to recirculate unused ammonia from the engine to the high-pressure pump.

[0017] The system further comprises a second fluid circuit comprises a bypass loop and at least one fourth valve disposed at the bypass loop. The bypass loop fluidly connects the engine to the heater and is configured to circulate heat exchange fluid between the heater and the engine. The system further comprises at least one air compressor connected to a crankshaft of the engine to independently clean the engine and first fluid circuit with compressed air. The system further comprises at least two heat exchangers and a pump for heating the ammonia source. The heat exchanger utilizes exhaust gases for heating purposes, while pump circulates water to heat exchanger, thereby elevating the ambient air temperature surrounding the ammonia tank or source.

[0018] The above summary contains simplifications, generalizations and omissions of detail and is not intended as a comprehensive description of the claimed subject matter but, rather, is intended to provide a brief overview of some of the functionality associated therewith. Othersystems, methods, functionality, features and advantages of the claimed subject matter will be or will become apparent to one with skill in the art upon examination of the following figures and detailed written description.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The description of the illustrative embodiments can be read in conjunction with the accompanying figures. It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements. Embodiments incorporating teachings of the present disclosure are shown and described with respect to the figures presented herein, in which:

[0020] FIG. 1 exemplarily illustrates a schematic of a system for supplying ammonia to a diesel engine, according to an embodiment of the present invention.

[0021] FIG. 2 exemplarily illustrates a first fluid circuit supplying ammonia directly to the engine cylinder, according to an embodiment of the present invention.

[0022] FIG. 3 exemplarily illustrates a Gasoline Direct Injection (GDI) type injector, according to an embodiment of the present invention.

[0023] FIG. 4 exemplarily illustrates a block diagram of a system for supplying ammonia to a diesel engine, according to an embodiment of the present invention.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0024] A description of embodiments of the present invention will now be given with reference to the Figures. It is expected that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

[0025] Referring to FIG. 1 and FIG. 4, the system 100 comprises a first fluid circuit, an engine 102 including a fuel rail system 104 and a second fluid circuit. The first fluid circuit comprises an ammonia source 106, a high-pressure pump 108 and a heater 110. The high-pressure pump108 is disposed downstream to the ammonia source 106 and upstream to the heater 110. The first fluid circuit provides a first fluid flow path from the ammonia source 106 to the engine 102.

[0026] The fuel rail system 104 includes at least one of an ammonia injector 112 and a diesel injector 114. The ammonia injector 112 is in fluid communication with the heater 110 of the first fluid circuit. The fuel rail system 104 is configured to directly supply ammonia in liquid phase into engine cylinders of an engine 102.

[0027] The first fluid circuit further comprises at least one first valve 116, at least one second valve 118, a low-pressure pump 122 and at least one third valve 120. The first valve 116 is disposed downstream to the heater 110 and the second valve 118 is disposed downstream to the first valve 116. The low-pressure pump 122 is disposed downstream to the engine 102 and in fluid communication with the high-pressure pump 108. The third valve 120 is disposed upstream to the low-pressure pump 122 and downstream to the engine 102.

[0028] The ammonia source 106 is configured to store ammonia. The high-pressure pump 108 is in fluid communication with the ammonia source 106 and downstream to the ammonia source 106. The high-pressure pump 108 is configured to deliver ammonia at a desired pressure in liquid phase. In one embodiment, the high-pressure pump 108 is a booster pump. In one embodiment, the high-pressure pump 108 is connected to a voltage supply network and a voltage converter to supply power to the high-pressure pump 108. The system 100 is configured to inject ammonia directly into the engine cylinder. In one embodiment, the booster pump delivers the liquid ammonia up to 70 bar to the fuel rial system 104.

[0029] The heater 110 is in fluid communication with the high-pressure pump 108 and downstream to the high-pressure pump 108. The heater 110 is configured to maintain ammonia in liquid phase. The heater 110 is disposed to avoid freezing and maintain the ammonia in a high-pressure state. The heater 110 is configured to utilize heat exchange fluid, for example, coolant from engine 102. The heater 110 is a vital component especially during the cold season, to prevent ammonia flow oscillations that could impair injection quality. Further, the higher pressure enhances the cylinder spray, thus improving combustion efficiency. The ammonia from the heater 110 flows to the engine 102 by passing through the first valve 116 and the second valve 118.

[0030] The second fluid circuit comprises a bypass loop 124 and at least one fourth valve 126 disposed at the bypass loop 124. The bypass loop 124 fluidly connects the engine 102 to the heater 110 and is configured to circulate heat exchange fluid between the heater 110 and the engine 102. The bypass loop 124 fluidically connects heat exchange pipes of the engine 102. The heat exchange pipes of the engine 102 are configured to circulate the heat exchange fluid. In an embodiment, the heat exchange fluid is a coolant. The coolant is supplied to the heater 110 or a small tank containing a winding ammonia circuit. In one embodiment, the fourth valve 126 is an electro valve. The system 100 is configured to regulate temperature with a range, for example, 30oC to 50oC. In another embodiment, the system 100 includes a heating thermostatic resistance. The heating thermostatic resistance could be placed in the water tank and powered by the engine alternator.

[0031] The system 100 is configured to provide safety measures utilizing the valves (116, 118), a mass flow meter 130 and an ammonia detector 128. The flow meter 130 and ammonia detector 128 is disposed at the first flow circuit. In one embodiment, the flow meter 130 is disposed downstream to the first valve 116 and upstream to the second valve 118. The ammonia detector 128 is connected to the first valve 116. In one embodiment, the first valve 116 is a first electro valve, which is configured to quickly close the line if ammonia leakage exceeds 25 ppm. In one embodiment, the second valve 118 is a second electro valve configured to function as a flame arrestor for safety.

[0032] The system further comprises one or more engine control units (134, 136) connected to the diesel injector 114 and the ammonia injector 112. The engine control unit (134, 136) is configured to control injection of diesel and ammonia. The engine control unit (134, 136) is configured to receive engine parameters and the ammonia related parameters. The engine control unit (134, 136) is configured to reduce diesel injection and compensate energy through ammonia injection.

[0033] In one embodiment, the engine control units (134, 136) comprise a first engine control unit (ECU1) 134 and a second engine control unit (ECU2) 136. The first engine control unit 134 is configured to control injection of diesel and the second engine control unit 136 is configured to control injection of ammonia.

[0034] The second engine control unit 136 is configured to receive one or more engine parameters. The first engine control unit 134 and second engine control unit 136 are configuredto receive parameters from one or more sensors including, but not limited to, engine speed sensors 146, intake valve position sensor 144, and temperature sensor. The parameters include, but not limited to, speed, Top Death Center (TDC) piston position and camshaft position. The second engine control unit 136 is configured to control the ammonia injectors 112. In one embodiment, the second engine control unit 136 is configured to enable direct ammonia injection into the cylinder using a Gasoline Direct Injection (GDI) type injector 150 (shown in FIG. 3), commonly used in light commercial vehicles.

[0035] In one embodiment, the second engine control unit 136 is configured to operate as an open-loop device with MS Tuner Studio software, allowing real-time modification of injection parameters. Further, the first engine control unit 134 is configured to reduce diesel injection and compensate energy through ammonia injection, controlled with INCA software. Further, the unused ammonia is recirculated to the first fluid circuit through the third valve 120 and the low- pressure pump 122 to the high-pressure pump 108.

[0036] The system 100 further comprises an air compressor 132 directly engaged with the engine's 102 crankshaft or independently cleans the engine 102 and circuit with compressed air. The system 100 further comprises at least two heat exchangers (140, 142) and a pump 138 for heating the ammonia source 106. The heat exchanger (140, 142) utilizes exhaust gases for heating purposes, while pump 138 circulates water to heat exchanger (140, 142), thereby elevating the ambient air temperature surrounding the ammonia tank or source 106.

[0037] The direct injection method of the system 100 elevates the injection pressure of the ammonia and enhances combustion through the increased presence of ammonia in the fuel mixture. The system 100 is employed to sustain pressure prior to injection via the high-pressure pump 108, alongside the heating of ammonia tank or source 106, and real-time adjustments orchestrated by the dual ECUs (134, 136), contingent upon the engine's 102 and piston's positioning.

[0038] The invention introduces the creation of specialized software to synthesize data from two distinct control units (134, 136), each overseeing a particular fuel type. This software harmonizes the parameters extracted from the units (134, 136) to refine the performance of a bi-fuel diesel engine 102. This amalgamation ensures more meticulous control and enhances the engine's 102 operational efficiency. The integration of all injection-related parameters within the said software also facilitates regular remote updates and ongoing enhancement. Thisfunction enables to carry out a range of tasks, including error diagnosis, software updates and alterations, and real-time visualization of parameters from any spot on the ship. This capability to remotely access the system 100 augments both the adaptability and promptness of system 100 administration and upkeep.

[0039] Referring to FIG. 2, the first fluid circuit comprising the high-pressure pump 108 and heater 110 maintaining ammonia in liquid phase, the standard diesel injector 114, and the ammonia injector 112. Referring to FIG. 3, the ammonia injector 112 is a specialized GDI injector 150.

[0040] Referring to FIG. 4, the first fluid circuit comprises the ammonia tank 106, the heater 110, the high-pressure (HP) pump 108, the first valve or electro valve 116, the second valve or flashback electro valve (EV) 118, the third valve 120, and the mass flow meter 130. The first fluid circuit further comprises the low-pressure (LP) pump 122 and ammonia detector 128. The system 100 further comprises the engine 102 comprising the fuel rail system 104, the first engine control unit 134, the second engine control unit 136, the diesel injector 114 and the ammonia injector 112. The first engine control unit 134 and the second engine control unit 136 are configured to receive signals related to the engine parameters to control injection of fuel. The signal loop is represented as 152.

[0041] The fuel injection procedure is bifurcated and controlled electronically by incorporating two Electronic Control Units (ECUs) (134, 136). The second engine control unit 136 serves as the control center for ammonia injection, entrusted with collecting all relevant parameters related to the ammonia process. This information is subsequently transmitted to first engine control unit 134. The first engine control unit 134 is the principal command unit for synchronization within a consolidated software structure. For example, this software is capable of handling up to 2000 engine parameters. The engine parameters including, but not limited to, engine speed (RPM), engine load / Torque (% / Nm), engine coolant temperature (° C), engine oil temperature (° C), ammonia temperature (° C), ammonia pressure (bar), intake valve position (rotation angle), piston position (rotation angle related by TDC), diesel and ammonia injection duration (ms), injected quantity both fuels (mg / strike), time of injection (rotation angle function TDC), rail pressure for both fuels (bar), external temperature (° C), intake air temperature (° C), intake air pressure (bar), exhaust gas pressure and temperature (bar, ° C) and oxygen presence in exhaust.

[0042] In one embodiment, the method of operation of the system 100 is disclosed. Initially, engine 102 starts normally with diesel fuel and the engine 102 coolant starts to heat. When the engine coolant reaches the predefined temperature, for example, 40 ° C, the system 100 is configured to inject ammonia. The system 100 comprises a temperature sensor, which gives signal to the valves (116, 118, 120) to open ammonia circuit, and then ammonia is pumped to the injection rail system 104. Further, the valve 126 opens the coolant circuit or the bypass loop 124 when the engine coolant exceeds 30 °C, with the process potentially lasting, for example, up to 5 minutes. The temperature-dependent opening provides seasonal flexibility. The engine coolant circulation is represented with numeral 148.

[0043] A rail pressure sensor is configured to enable ammonia injectors 112 when a targeted pressure is provided in the rail. In the same time ECU (134, 136) receives information about the intake valve position, engine piston position and engine speed from different sensors installed on the engine 102. When the user demands certain engine regime and power, the software is configured to request first 100% diesel percentage and after establishing a constant regime, the system 100 is configured to reduce injection of diesel and increase ammonia rate to an optimal percentage (up to 85% energy fraction) to reduce emission. The software is calibrated during a validation of performance. The calibration assesses performance and emissions with the lengths, durations and timings of the ammonia injection and diesel parameters. The oxygen quantity measured in the exhaust enables to provide information of burning fuel quality and emissions levels. During the validation process, data are collected and modified using MS Tuner Studio or INCA and the software with all the calibrations of parameters may be assembled by INCA software, which is generally a code used in automotive area.

[0044] During implementation at small engines, ammonia injection may be performed with the Gasoline Direct Injection (GDI) type injector 150 customized for our purpose. For the large engine, injectors may be a very fast response valve, with a larger diameter but having also similar electronic control. The ammonia injector 112 could be added by drilling a hole in the cylinder head and ammonia could be sprayed directly into the cylinder, after a small quantity of gasoil has been already injected and burned in order to create burning conditions. So, gasoil could be used only as a burning promoter and ammonia is used to replace the most of classic fuel, which contains carbon as a difference of ammonia which in neutral by this criterion. Further, a unique aspect of the injection system 100 lies in the uniformity of the hardware components across different engines, with the only variations occurring in the injectors, which may differ innumber and size. However, the software could be tailored to each individual engine, with its tuning being reliant on specific engine characteristics.

[0045] Further, the merits of utilizing direct injection at elevated pressures and temperatures could be traced back to the distinct characteristics of ammonia, which are discussed as follows. The system 100 is configured to improve atomization. Injecting ammonia at higher pressures and temperatures leads to better atomization, resulting in finer droplets. This improves the mixture of the ammonia with air, leading to more complete combustion and potentially higher efficiency. Further, the direction injection of ammonia allows for precise control over the timing and quantity of the injected ammonia. This leads to a more responsive system that could quickly adapt to different engine loads and conditions, improving fuel efficiency and reducing emissions. Further, ammonia's density increases with pressure, allowing more fuel to be injected in the same volume. This could lead to a more energy-dense air-fuel mixture, potentially increasing power output and efficiency. These NH3 states are summarized in Table 1.

[0046] Table 1 - Ammonia Properties at different pressures states

[0047] The table illustrates that both density and heat capacity experience an increase with a rise in pressure, enhancing combustion efficiency with greater amounts of ammonia. By injecting more ammonia, diesel fuel can be substituted, leading to a reduction in fuel consumption and emissions.

[0048] The system 100 further avoids premixing issues. Generally, injecting ammonia into the intake manifold at lower pressures and temperatures may lead to incomplete mixing or phase separation issues. However, according to the present invention, direct injection at higher pressures and temperatures mitigates these issues, leading to a more homogeneous mixture. The system 100 enhances control over combustion process. Direct injection allows for better control over the combustion process. By controlling the pressure and temperature of the injected ammonia, the combustion could be optimized for different operating conditions, leading to reductions in fuel consumption and emissions.

[0049] The system 100 further reduces CO2 and smoke emissions. Ammonia act as a reducing agent for these emissions due to lack of carbon presence in its molecule. By optimizing the direct injection process, the present invention enables to emit insignificant emissions level. However, a slightly increasing of NOx is expected, but these emissions will be treated similar to automotive, with SCR systems. The system 100 is compatible with different engine types. The direct injection of the present invention could be tailored to suit different types of engines, including engines with advanced combustion strategies. This flexibility could make the present invention more widely applicable.

[0050] Advantageously, by employing these components and functionalities, the disclosed system 100 aims to efficiently utilize ammonia as a fuel in large diesel engines, considering safety, temperature regulation, real-time control, and adherence to relevant environmental directives. The system 100 encompassing software-controlled direct injection of ammonia into diesel engines 102, could be utilized to power large marine engines. The underlying objective of incorporating ammonia is to diminish both CO and NO emissions while also achieving reduced operating expenses. Specifically, the combustion of ammonia as a main fuel source leads to substantially lower CO and smoke emissions. Through the utilization of an after-treatment device, NO emissions can also be significantly curtailed. Furthermore, electronic control of combustion enhances the system's 100 operability, extending its functional range to encompass both low-load and high-regime situations. Additionally, the use of ammonia as a fuel, being relatively more affordable than conventional fuels, translates into considerable financial savings within the described power system.

[0051] While the disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular system, device or component thereof to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiments disclosed for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

[0052] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0053] The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the disclosure. The described embodiments were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMS1 . A system (100) for supplying ammonia to a diesel engine, comprising: a first fluid circuit configured to supply ammonia, wherein the first fluid circuit comprises: an ammonia source (106) configured to store ammonia, a high-pressure pump (108) in fluid communication with the ammonia source (106) configured to deliver ammonia at a desired pressure in liquid phase, and a heater (110) in fluid communication with the high-pressure pump (108) configured to maintain ammonia in the liquid phase; an engine (102) including a fuel rail system (104) in fluid communication with the first fluid circuit, wherein the fuel rail system (104) comprising at least one ammonia injector (112) and at least one diesel injector (114), wherein the ammonia injector (112) is in fluid communication with the heater (110), wherein the fuel rail system (104) is configured to directly supply ammonia in liquid phase into engine cylinders via the ammonia injector (112) and supply diesel via the diesel injector (114), and one or more engine control units (134, 136) connected to the diesel injector (114) and the ammonia injector (112), wherein the engine control unit (134, 136) is configured to control injection of diesel and ammonia, wherein the engine control unit (134, 136) is configured to receive engine parameters and the ammonia related parameters, wherein the engine control unit (134, 136) is configured to reduce diesel injection and compensate energy through ammonia injection.

2. The system (100) of claim 1 , wherein the engine control units (134, 136) comprise: a first engine control unit (134) connected to the diesel injector (114) configured to control injection of diesel, and a second engine control unit (136) connected to the ammonia injector (112) configured to control injection of ammonia, wherein the first engine control unit (134) and second engine control unit(136) are configured to receive engine parameters and the ammonia related parameters, wherein the first engine control unit (134) is configured to reduce diesel injection and compensate energy through ammonia injection.

3. The system (100) of the preceding claim, wherein the first engine control unit (134) and second engine control unit (136) are configured to receive engine parameters from one or more sensors including engine speed sensors (146), intake valve position sensor (144), temperature sensor and rail pressure sensor.

4. The system (100) of either of the two directly preceding claims, wherein the second engine control unit (136) is configured to control injection of ammonia directly into the engine cylinders using a Gasoline Direct Injection (GDI) type injector, and the second engine control unit (136) is configured to operate as an open-loop device and modifies engine parameters and ammonia related parameters in real-time.

5. The system (100) of any preceding claim, wherein the high-pressure pump (108) is disposed downstream to the ammonia source (106) and upstream to the heater (110).

6. The system (100) of any preceding claim, wherein the first fluid circuit further comprises at least one first valve (116) disposed downstream to the heater (110), optionally wherein the first fluid circuit further comprises at least one second valve (118) disposed downstream to the first valve (116), optionally wherein the first fluid circuit further comprises a mass flow meter (130) disposed downstream to the first valve (116) and upstream to the second valve (118).

7. The system (100) of the preceding claim, further comprising an ammonia detector (128) coupled to the first valve (116), wherein the ammonia detector (128) is configured to detect leakage of ammonia, and wherein the first valve (116) is configured to close on leakage of ammonia exceeding a predefined amount, optionally wherein the second valve (118) is configured to close on detecting backflow of leakage ammonia.

8. The system (100) of any preceding claim, wherein the engine (102) is configured to start to operate with the diesel fuel and the first fluid circuit is configured to supply ammonia when a temperature of a heat exchange fluid at the engine (102) reaches a predefined temperature.

9. The system (100) of any preceding claim, wherein the first fluid circuit further comprises a low-pressure pump (122) in fluid communication with the engine (102) and the high-pressurepump (108), wherein the low-pressure pump (122) is disposed downstream to the engine (102) and upstream to the high-pressure pump (108).

10. The system (100) of any preceding claim, wherein the first fluid circuit further comprises at least one third valve (120) disposed between the low-pressure pump (122) and the engine (102), wherein the low-pressure pump (122) is configured to recirculate unused ammonia from the engine (102) to the high-pressure pump (108).

11. The system (100) of any preceding claim, further comprises a second fluid circuit comprises a bypass loop (124) and at least one fourth valve (126) disposed at the bypass loop (124), optionally wherein the bypass loop (124) fluidly connects the engine (102) to the heater (110) and configured to circulate heat exchange fluid between the heater (110) and the engine (102).

12. The system (100) of any preceding claim, further comprises at least one air compressor (132) connected to a crankshaft of the engine (102) to independently clean the engine (102) and first fluid circuit with compressed air.

13. The system (100) of any preceding claim, wherein the engine parameters and ammonia related parameters include intake valve position, engine piston position, engine speed from different sensors installed on the engine, oxygen quantity measured in the exhaust, engine coolant temperature, engine oil temperature, ammonia temperature, ammonia pressure, diesel and ammonia injection duration, injected quantity fuels, time of injection of diesel and ammonia, rail pressure for diesel and ammonia, external temperature, intake air temperature, intake air pressure, and exhaust gas pressure and temperature.

14. The system (100) of any preceding claim, further comprises at least two heat exchangers (140, 142) and a pump (138) disposed in fluid communication with the engine (102) and ammonia source (106), optionally wherein the heat exchanger (140, 142) utilizes exhaust gases for heating purposes, while pump (138) circulates water to heat exchanger (140, 142), thereby elevating an ambient air temperature surrounding the ammonia source (106).

15. The system (100) of any preceding claim, is configured to harmonize the engine parameters and ammonia related parameters extracted from the first engine control unit (134) and the second engine control unit (136) to refine performance of the engine.

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