Rankine cycle device of internal combustion engine

• US 20040060292A1
• Filed: 10/29/2003
• Published: 04/01/2004
• Est. Priority Date: 10/11/2000
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Yoshida, Kazuo, Miura, Hiroyuki, Minemi, Masahiko, Miyao, Masakatsu
• Granted Patent: US 6,910,333 B2
• Time in Patent Office: Days
• US Class Current: 60/616
• CPC Class Codes: F01B 17/04 Steam engines
• CPC Class Codes: F01K 23/065 the combustion taking place in an internal combustion piston engine, e.g. a diesel engine
• CPC Class Codes: F01K 23/106 with water evaporated or preheated at different pressures in exhaust boiler
• CPC Class Codes: F01N 3/2006 Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 3/2882 Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices combined with absorbents or adsorbents only F01N3/0814; combined with particulate filters F01N3/035
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: F02G 1/04 of closed-cycle type
• CPC Class Codes: F02G 5/04 in combination with other waste heat from combustion engines
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A Rankine cycle system includes a first Rankine cycle (2A) operated by a first working medium and a second Rankine cycle (2B) operated by a second working medium. The first Rankine cycle (2A) is constituted from an evaporator (3A), an expander (4), a condenser (5A) and a supply pump (6A), and the second Rankine cycle (2B) is constituted from an evaporator (3B), the expander (4), a condenser (5B) and a supply pump (6c). The evaporator (3A) in the first Rankine cycle (2A) and the evaporator (3B) in the second Rankine cycle (2B) are disposed at locations upstream and downstream of an exhaust emission control device (8) mounted in an exhaust passage (7) for the internal combustion engine (1). The first working medium has a boiling point higher than that of the second working medium, and the capacity of the pump (6A) in at least the first Rankine cycle (2A) is variable. Thus, the efficiency of recovery of a waste heat from the internal combustion engine by the Rankine cycle system can be enhanced to the maximum, and the activation of the exhaust emission control device can be promoted.

Claims

1. A Rankine cycle system for an internal combustion engine, comprising a first Rankine cycle (2A) operated by a first working medium and a second Rankine cycle (2B) operated by a second working medium, each of the Rankine cycles (2A and 2B) being comprised of an evaporator (3A, 3B) for heating a liquid-phase working medium by waste heat from the internal combustion engine (1) to generate a vapor, an expander (4) for converting the heat energy of the vapor discharged by said evaporator (3A, 3B) into a mechanical energy, a condenser (5A, 5B) for cooling the vapor discharged by said expander (4) to return the vapor into the liquid-phase working medium, and a supply pump (6A, 6B) for supplying the water discharged by said condenser (5A, 5B) to said evaporator (3A, 3B), wherein

said evaporator (3A) in said first Rankine cycle (2A) and said evaporator (3B) in said second Rankine cycle (2B) are respectively disposed at locations upstream and downstream of an exhaust emission control device (8) mounted in an exhaust passage (7) for the internal combustion engine (1);

said first working medium is of a boiling point higher than that of said second working medium; and

the capacity of said supply pump (6A) in at least said first Rankine cycle (2A) is variable.

2. A Rankine cycle system for an internal combustion engine according to claim 1, wherein said expander (4) includes higher-pressure expanding portions (33) and lower-pressure expanding portions (50), so that outputs from both of said expanding portions (33 and 50) can be united together and output from a common rotary shaft (21);

the vapor of said first working medium is supplied to said higher-pressure expanding portions (33); and

the vapor of said second working medium is supplied to said lower-pressure expanding portions (50).