Systems and methods for providing a diesel-methanol emulsion for direct injection engines

Patent metadata

Field	Value
Publication number	US-12429005-B2
Application number	US-202318466066-A
Country	US
Kind code	B2
Filing date	Sep 13, 2023
Priority date	Sep 13, 2023
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

An internal combustion engine system is described herein. The system uses a mixer to mix two fuels to provide for a transition from using only one of the fuels to using only the other fuel as power demand changes. The output of the mixer is provided to the engine as a primary fuel. A controller opens and closes throttle valves to adjust the relative concentrations of a first fuel (e.g., diesel) and a second fuel (e.g., methanol) that enter the mixer. In some examples, rather than removing the desired performance and/or environmental benefits achieved by using the second fuel at power demand levels greater than the maximum achievable by only using the second fuel, the systems described herein allow the use of at least a portion of the second fuel in the primary fuel at those power demand levels.

First claim

What is claimed is:

1. A system comprising:
an internal combustion engine that combusts a primary fuel and a pilot fuel;
a first fuel tank for storing a first fuel;
a second fuel tank for storing a second fuel;
a first fuel metering valve for controlling a first fuel flowrate of the first fuel exiting the first fuel tank;
a second fuel metering valve for controlling a second fuel flowrate of the second fuel exiting the second fuel tank; and
a mixer configured to receive the first fuel via the first fuel metering valve and the second fuel via the second fuel metering valve, and to output a mixture of the received first fuel and second fuel to a primary fuel rail for use by the engine as the primary fuel, wherein a position of the first fuel metering valve determines a concentration of the first fuel in the primary fuel output by the mixer, a position of the second fuel metering valve determines a concentration of the second fuel in the primary fuel, and at least a portion of the first fuel is directed from the first fuel tank to the engine for use as the pilot fuel.

2. The system of claim 1 , further comprising:
a first fuel pump in fluidic communication with the first fuel, wherein the first fuel pump pumps the first fuel from the first fuel tank to a block;
the block having internal ports for directing a first portion of the first fuel to a pilot fuel rail, wherein the first portion of the first fuel is the pilot fuel for use by the engine, and wherein a second portion of the first fuel is directed to the first fuel metering valve; and
a second fuel pump in fluidic communication with the second fuel in the second fuel tank, wherein the second fuel pump pumps the second fuel into a tee.

3. The system of claim 1 , further comprising:
a first fuel metering valve for measuring a flow of the first fuel through the first fuel metering valve; and
a second fuel flowmeter for measuring a flow of the second fuel through the second fuel metering valve.

4. The system of claim 1 , further comprising a composition sensor configured to measure a concentration of the first fuel and a concentration of the second fuel in the mixer output.

5. The system of claim 1 , further comprising:
a cooler for cooling an excess primary fuel, wherein the excess primary fuel is uncombusted primary fuel not injected into a combustion chamber of the engine;
an excess primary fuel flowmeter for measuring a flowrate of the excess primary fuel;
a mixture pump for pumping at least a portion of the excess primary fuel and the output of a tee into the mixer; and
a mixture tank for receiving and storing the excess primary fuel not pumped back into the mixer.

6. The system of claim 1 , further comprising a controller, the controller comprising:
a memory storing computer-executable instructions; and
a processor in communication with the memory, the computer-executable instructions causing the processor to perform acts comprising:
monitoring the system;
receiving a power demand input;
retrieving a first fuel flowrate and retrieving a second fuel flowrate from an engine map based on the power demand input;
issuing a first fuel control signal to the first fuel metering valve to cause the first fuel metering valve to adjust to a first fuel metering valve position to achieve the first fuel flowrate; and
issuing a second fuel control signal to the second fuel metering valve to cause the second fuel metering valve to adjust a second fuel metering valve position to the position based on the second fuel control signal.

7. The system of claim 6 , wherein the controller further comprises computer-executable instructions that cause the processor to perform acts comprising:
receiving a composition input indicating a concentration of the first fuel and a concentration of the second fuel in the output of a tee; and
adjusting the first fuel metering valve position or a second fuel metering valve position to achieve the first fuel flowrate and the second fuel flowrate.

8. The system of claim 6 , wherein the first fuel flowrate and the second fuel flowrate transitions from:
a first configuration wherein the second fuel is a sole component of the primary fuel;
a second configuration wherein the first fuel and the second fuel are mixed in the mixer as the primary fuel, wherein the primary fuel comprises an emulsion of the first fuel and the second fuel; and
a third configuration wherein the first fuel is the sole component of the primary fuel.

9. The system of claim 1 , wherein the mixer comprises a low-shear/high-flow mixer or comprises a high-shear/low-flow mixer.

10. The system of claim 1 , wherein the mixer comprises a liquid-liquid mixer or a gas-liquid mixer.

11. A method of operating a system, the method comprising:
monitoring, by a controller, the system, the system comprising:
an internal combustion engine that combusts a primary fuel and a pilot fuel;
a first fuel tank for storing a first fuel;
a second fuel tank for storing a second fuel;
a first fuel metering valve for controlling a first fuel flowrate of the first fuel exiting the first fuel tank;
a second fuel metering valve for controlling a second fuel flowrate of the second fuel exiting the second fuel tank; and
a mixer configured to receive the first fuel via the first fuel metering valve and the second fuel via the second fuel metering valve, and to output a mixture of the received first fuel and second fuel to a primary fuel rail for use by the engine as the primary fuel, wherein a position of the first fuel metering valve determines a concentration of the first fuel in the primary fuel output by the mixer, a position of the second fuel metering valve determines a concentration of the second fuel in the primary fuel, and at least a portion of the first fuel is directed from the first fuel tank to the engine for use as the pilot fuel; and
receiving, by the controller, a power demand input;
retrieving, by the controller, a first fuel flowrate and retrieving a second fuel flowrate from an engine map based on the power demand input;
issuing, by the controller, a first fuel control signal to the first fuel metering valve to cause the first fuel metering valve to adjust to a first fuel metering valve position to achieve the first fuel flowrate; and
issuing, by the controller, a second fuel control signal to the second fuel metering valve to cause the second fuel metering valve to adjust a second fuel metering valve position to the position based on the second fuel control signal.

12. The method of claim 11 , further comprising:
receiving, by the controller, a composition input indicating a concentration of the first fuel and a concentration of the second fuel in the output of a tee; and
adjusting, by the controller, the first fuel metering valve position or a second fuel metering valve position to achieve the first fuel flowrate and the second fuel flowrate.

13. The method of claim 11 , wherein the first fuel flowrate and the second fuel flowrate transitions from:
a first configuration wherein the second fuel is a sole component of the primary fuel;
a second configuration wherein the first fuel and the second fuel are mixed in the mixer as the primary fuel, wherein the primary fuel comprises an emulsion of the first fuel and the second fuel; and
a third configuration wherein the first fuel is the sole component of the primary fuel.

14. The method of claim 11 , further comprising:
measuring a flow of the first fuel through the first fuel metering valve; and
measuring a flow of the second fuel through the second fuel metering valve.

15. The method

Assignees

• Caterpillar Inc

Inventors

• Gerstner Michael David
• Baldwin Daniel Raymond
• Graumüller Robert
• Schroeder Eric Lee

Classifications

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title

• F02D19/0613

  Switch-over from one fuel to another (F02D19/081 takes precedence) · CPC title

• F02D19/0628

  Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position · CPC title

• F02D19/081

  Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other · CPC title

• F02D19/0665

  Tanks, e.g. multiple tanks · CPC title