Ultra-high efficiency alcohol engines using optimized exhaust heat recovery

Patent metadata

Field	Value
Publication number	US-9234482-B2
Application number	US-201313952766-A
Country	US
Kind code	B2
Filing date	Jul 29, 2013
Priority date	Aug 2, 2012
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

Engine system using alcohol Rankine heat recovery where the engine heat converts alcohol into hydrogen-rich gas which is then introduced into the engine cylinders. The engine system includes a source of liquid alcohol along with an internal combustion engine generating a high temperature exhaust. Structure is provided for introducing a first portion of the liquid alcohol into the engine and a series of heat exchangers forming a Rankine heat recovery cycle is provided to extract heat from the exhaust and transferring the heat to a second portion of the liquid alcohol, causing it to change phase to a gaseous alcohol. A heat exchanger/catalyst is heated by the exhaust to reform the gaseous alcohol into a hydrogen-rich reformate.

First claim

What is claimed is:

1. An engine system comprising;
a source of liquid alcohol;
an internal combustion engine generating exhaust gas;
a structure for introducing a first portion of the liquid alcohol into the engine;
a series of heat exchangers forming a Rankine heat recovery cycle extracting heat from the exhaust gas and transferring the heat to a second portion of the liquid alcohol causing it to change phase to a gaseous alcohol;
a heat exchanger/catalyst heated by the exhaust to reform the alcohol into a hydrogen-rich reformate;
a valve structure for introducing the reformate into the engine for combustion; and
a control system for controlling a ratio of the first and second portions of the liquid alcohol to maximize an amount of the second portion of the liquid alcohol while using a minimum amount of the first portion needed to prevent knock, further including an additional heat exchanger extracting heat from engine cooling water to preheat the liquid alcohol.

2. The engine system of claim 1 further including a turbine through which the reformate flows before introduction into the engine.

3. The engine system of claim 1 wherein the engine is operated with a lean fuel-to-air ratio.

4. The engine system of claim 1 wherein the engine is operated with EGR.

5. The engine system of claim 1 wherein the heat exchanger/catalyst includes a metallic foam.

6. The engine system of claim 5 wherein the metallic foam is disposed on fins.

7. The engine system of claim 1 wherein the alcohol is methanol.

8. The engine system of claim 1 wherein the alcohol is ethanol.

9. The engine system of claim 1 wherein the engine is a spark ignition engine and the reformate is introduced into engine cylinders.

Assignees

• Massachusetts Inst Technology

Inventors

• Bromberg Leslie
• Cohn Daniel R

Classifications

• F02M25/00 Primary

  Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture (adding secondary air to fuel-air mixture F02M23/00; adding exhaust gases F02M26/00; fuel-injection apparatus operating simultaneously on two or more fuels or on a liquid fuel and another liquid F02M43/00) · CPC title

• F02D41/0027

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title

• F02D19/0655

  at least one fuel being an alcohol, e.g. ethanol (F02D19/084 takes precedence) · CPC title

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F01K23/065

  the combustion taking place in an internal combustion piston engine, e.g. a diesel engine · CPC title