US-12617673-B2 - Systems and methods for phase-safe ammonia vapor fuel delivery to an internal combustion engine

Abstract

The present invention relates, in general, to systems and methods for generating hydrogen from ammonia on-board vehicles, where the produced hydrogen is used as a co-fuel for an internal combustion engine along with ammonia vapor. The present invention provides a safety control arrangement for ensuring that only ammonia vapor is delivered to the engine's ammonia fuel injectors, resulting in consistent metering, mixing, and safe combustion, whereas liquid ammonia would otherwise introduce instability, mechanical stress, and dangerous expansion risks.

Inventors

• James L. Wall, II
• David Gwynn Kapp, Jr.
• James Francis Lamb

Assignees

• First Ammonia Motors, Inc.

Dates

Publication Date

20260505

Application Date

20250922

Claims (20)

1. 1 . A system for preventing liquid ammonia from entering an internal combustion engine, comprising: at least one fuel injector coupled to the internal combustion engine; a fuel rail configured to distribute ammonia to the at least one fuel injector; a supply line configured to deliver ammonia to the fuel rail; a shutoff valve fluidly coupled between the fuel rail and the supply line; and an electronic control unit (ECU) configured to determine if the ammonia in the supply line is in a vapor phase or a liquid phase, wherein the ECU controls the shutoff valve to close if the ammonia in the supply line is determined to be in a liquid phase, thereby preventing liquid ammonia from being delivered to the fuel rail from the supply line.
2. 2 . The system of claim 1 , further comprising a sensor module configured to detect a temperature and a pressure of the ammonia in the supply line.
3. 3 . The system of claim 2 , wherein the sensor module comprises a temperature sensor and a pressure sensor.
4. 4 . The system of claim 1 , wherein the ECU determines if the ammonia in the supply line is in a vapor phase or a liquid phase based on a temperature of the ammonia in the supply line.
5. 5 . The system of claim 1 , wherein the ECU determines if the ammonia in the supply line is in a vapor phase or a liquid phase based on a pressure of the ammonia in the supply line.
6. 6 . The system of claim 1 , wherein the ECU determines if the ammonia in the supply line is in a vapor phase or a liquid phase based on a temperature and a pressure of the ammonia in the supply line.
7. 7 . The system of claim 1 , wherein the ECU determines if the ammonia in the supply line is in a vapor phase or a liquid phase by comparing a temperature of the ammonia in the supply line to a known condensation temperature at a detected pressure of the ammonia in the supply line.
8. 8 . A system for preventing liquid ammonia from entering an internal combustion engine, comprising: at least one fuel injector coupled to the internal combustion engine; a fuel rail configured to distribute ammonia to the at least one fuel injector; a supply line configured to deliver ammonia to the fuel rail; a shutoff valve fluidly coupled between the fuel rail and the supply line; a sensor module configured to detect a temperature and a pressure of the ammonia in the supply line; and an electronic control unit (ECU) configured to determine if the ammonia in the supply line is in a vapor phase or a liquid phase based on the detected temperature and pressure, wherein the ECU controls the shutoff valve to close if the ammonia in the supply line is determined to be in a liquid phase, thereby preventing liquid ammonia from being delivered to the fuel rail from the supply line.
9. 9 . The system of claim 8 , wherein the sensor module comprises a temperature sensor and a pressure sensor.
10. 10 . The system of claim 9 , wherein the temperature sensor is selected from a group consisting of a thermocouple, resistance temperature detector (RTD), a thermistor, an infrared sensor, and a semiconductor-based temperature sensors.
11. 11 . The system of claim 9 , wherein the pressure sensor is selected from a group consisting of a piezoresistive sensor, a capacitive sensor, a piezoelectric sensor, a strain-gauge sensor, a resonant sensor, and an optical fiber-based sensor.
12. 12 . The system of claim 8 , wherein the shutoff valve is of a type selected from a group consisting of mechanical, electrical, pneumatic, and hydraulic.
13. 13 . The system of claim 8 , wherein the ECU determines if the ammonia in the supply line is in a vapor phase or a liquid phase by comparing the detected temperature of the ammonia in the supply line to a known condensation temperature at the detected pressure of the ammonia in the supply line.
14. 14 . A system for preventing liquid ammonia from entering an internal combustion engine, comprising: at least one fuel injector coupled to the internal combustion engine; a fuel rail configured to distribute ammonia to the at least one fuel injector; a supply line configured to deliver ammonia to the fuel rail; a shutoff valve fluidly coupled between the fuel rail and the supply line; a sensor module configured to detect a temperature and a pressure of the ammonia in the supply line; and an electronic control unit (ECU) configured to determine if the ammonia in the supply line is in a vapor phase or a liquid phase by comparing the detected temperature of the ammonia in the supply line to a known condensation temperature at the detected pressure of the ammonia in the supply line, wherein the ECU controls the shutoff valve to close if the ammonia in the supply line is determined to be in a liquid phase, thereby preventing liquid ammonia from being delivered to the fuel rail from the supply line.
15. 15 . The system of claim 14 , wherein the temperature sensor is selected from a group consisting of a thermocouple, resistance temperature detector (RTD), a thermistor, an infrared sensor, and a semiconductor-based temperature sensors.
16. 16 . The system of claim 14 , wherein the pressure sensor is selected from a group consisting of a piezoresistive sensor, a capacitive sensor, a piezoelectric sensor, a strain-gauge sensor, a resonant sensor, and an optical fiber-based sensor.
17. 17 . The system of claim 14 , wherein the shutoff valve is of a type selected from a group consisting of mechanical, electrical, pneumatic, and hydraulic.
18. 18 . The system of claim 14 , wherein the shutoff valve is selected from a group consisting of a solenoid valve, a ball valve, a gate valve, a needle valve, a check valve, a pilot-operated valve, and a fail-safe valve.
19. 19 . The system of claim 14 , wherein the ECU further controls the shutoff valve to open if the ammonia in the supply line is determined to be in a vapor phase after closing the shutoff valve.
20. 20 . The system of claim 14 , wherein the sensor module continuously detects the temperature and pressure of the ammonia in the supply line, and wherein the ECU continuously determines if the ammonia in the supply line is in a vapor phase or a liquid phase.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of, and claims the benefit of, U.S. patent application Ser. No. 19/222,161, entitled “SYSTEMS AND METHODS FOR SUPPLEMENTING AN AMMONIA HEAT-EXCHANGE UNIT FOR ENGINE COOLING WITH A RADIATOR”, filed on May 29, 2025, which is a continuation of, and claims the benefit of, U.S. Pat. No. 12,358,787 entitled “SYSTEMS AND METHODS FOR AN INTERNAL COMBUSTION ENGINE UTILIZING AMMONIA AS A FUEL SOURCE AND AS A HEAT-EXCHANGE MEDIUM FOR ENGINE COOLING” filed on Oct. 1, 2024, which is a continuation-in-part of, and claims the benefit of, U.S. Pat. No. 12,162,754 entitled “SYSTEMS AND METHODS FOR ENGINE-MOUNTED CATALYTIC PRODUCTION OF HYDROGEN FROM AMMONIA FOR USE AS A COMBUSTION FUEL” filed on May 10, 2024, which is a continuation-in-part of, and claims the benefit of, U.S. Pat. No. 11,981,562 entitled “SYSTEMS AND METHODS FOR THE ON-BOARD CATALYTIC PRODUCTION OF HYDROGEN FROM AMMONIA USING A HEAT EXCHANGE CRACKING UNIT AND AN ELECTRIC CRACKING UNIT OPERATING IN SERIES” filed on Sep. 1, 2023, which is a continuation of, and claims the benefit of, U.S. Pat. No. 11,840,449 filed on Nov. 14, 2022, which claims the benefit of U.S. Provisional Patent Application No. 63/395,820 entitled “SYSTEMS AND METHODS FOR THE CATALYTIC PRODUCTION OF HYDROGEN FROM AMMONIA ON-BOARD MOTOR VEHICLES” filed on Aug. 6, 2022, U.S. Provisional Patent Application No. 63/355,959 entitled “SYSTEMS AND METHODS FOR THE CATALYTIC PRODUCTION OF HYDROGEN FROM AMMONIA ON-BOARD MOTOR VEHICLES” filed on Jun. 27, 2022, and U.S. Provisional Patent Application No. 63/312,121 entitled “SYSTEMS AND METHODS FOR THE CATALYTIC PRODUCTION OF HYDROGEN FROM AMMONIA ON-BOARD MOTOR VEHICLES” filed on Feb. 21, 2022, all of which are commonly owned, the disclosure of each is incorporated herein by reference in their entireties. BACKGROUND Field of the Invention The present invention relates, in general, to systems and methods for generating hydrogen from ammonia on-board vehicles, where the produced hydrogen is used as fuel source for an internal combustion engine, and where ammonia is used as a heat-exchange medium for a cooling system of the internal combustion engine. Description of Related Art The increase in the overall temperature on and above Earth's surface represents a critical challenge facing the planet. Earth's climate is significantly changing mainly due to human activities, and the transportation sector plays a prominent role in this global warming. For example, internal combustion engines have traditionally burned fossil fuels, which in turn produces CO2, a known contributor to global warming. Over the last decade, the transportation sector has made strides in making electric- and hybrid-powered vehicles available on a mass scale. Most electric and hybrid vehicles sold today tend to produce significantly fewer global warming emissions than most vehicles operating on fossil fuels, namely gasoline. However, the environmental benefits of electric and hybrid vehicles still depend primarily on how much fossil fuel is being burned to charge these vehicles. For example, if the vehicles are charged using a coal-heavy power grid, the environmental benefits are lessened. Furthermore, the batteries and fuel cells in electrified vehicles rely on raw materials such as cobalt, lithium and rare earth elements. These materials have been linked to grave environmental and human rights concerns. For instance, cobalt has been especially problematic. Mining cobalt produces hazardous tailings and slags that can leach into the environment, and studies have found high exposure rates of cobalt and other metals in communities surrounding cobalt mining and processing facilities. Extracting such metals from their ores also requires a process called smelting, which can emit sulfur oxide and other harmful air pollution. Given the sustained environmental issues that currently exist with electrified vehicles, ammonia has been suggested as an alternative to fossil fuels for use in internal combustion engines, given its relatively high energy density and zero CO2 emissions when combusted. However, pure ammonia cannot efficiently be used as a fuel in small internal combustion engines, whether spark-ignited (i.e., gasoline), or compression ignited (i.e., diesel), because pure ammonia burns too slowly to complete combustion during the power stroke in a four-stroke engine operating at speeds of thousands of revolutions per minute (RPM). In other words, when ammonia is combusted, the combustion produces a flame with a relatively low propagation speed. This low combustion rate of ammonia causes combustion to be inconsistent under low engine load and high engine speed operating conditions. Prior approaches to fueling combustion engines with ammonia or hydrogen alone have required mixing the ammonia or hydrogen with a secondary combustion promoter fuel, such as gasoline, liquefied petroleum, or diesel. However, the re