WORKING-GAS-CIRCULATION-TYPE ENGINE

• US 20090188476A1
• Filed: 08/10/2007
• Published: 07/30/2009
• Est. Priority Date: 09/07/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sasajima, Takashi, Sawada, Daisaku
• Granted Patent: US 7,661,416 B2
• Time in Patent Office: Days
• US Class Current: 123/568.120
• CPC Class Codes: F01N 2240/02 a heat exchanger
• CPC Class Codes: F02B 2275/14 Direct injection into combustion chamber
• CPC Class Codes: F02B 43/10 Engines or plants characterised by use of other specific gases, e.g. acetylene, oxyhydrogen
• CPC Class Codes: F02D 19/024 by controlling fuel injectors
• CPC Class Codes: F02D 19/12 peculiar to engines working with non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel
• CPC Class Codes: F02D 21/04 with circulation of exhaust gases in closed or semi-closed circuits
• CPC Class Codes: F02M 21/0206 Non-hydrocarbon fuels, e.g. hydrogen, ammonia or carbon monoxide
• CPC Class Codes: F02M 21/0275 for in-cylinder direct injection, e.g. injector combined with spark plug
• CPC Class Codes: F02M 25/10 adding acetylene, non-waterborne hydrogen, non-airborne oxygen, or ozone
• CPC Class Codes: F02M 26/35 with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

In an engine 10, oxygen, hydrogen serving as fuel, and argon gas serving as a working gas are supplied to a combustion chamber 21. An upstream condenser section 70 condenses water vapor contained in an exhaust gas to yield primary condensed water, through heat exchange of the exhaust gas from the combustion chamber with the ambient air, and discharges, as a primary-condensed-water-separated gas, a gas obtained by separating the primary condensed water from the exhaust gas. The primary condensed water is stored in a water storage tank 100. A downstream condenser section 80 further condenses water vapor contained in the primary-condensed-water-separated gas to yield secondary condensed water, through utilization of latent heat of vaporization of condensed water stored in the storage tank 100, and discharges a gas obtained by separating the secondary condensed water from the primary-condensed-water-separated gas. This avoids a significant drop in ratio of specific heats of the working gas.

Claims

1. A working-gas-circulation-type engine in which oxygen, a fuel that generates water vapor through combustion, and a working gas higher in ratio of specific heats than water vapor are supplied to a combustion chamber, the fuel is burnt in the combustion chamber so as to expand the working gas and thus output power, and the working gas contained in a post-combustion gas exhausted from the combustion chamber is resupplied to the combustion chamber through a circulation passage, comprising:

a first condenser section provided in the circulation passage and adapted to condense water vapor contained in a circulation gas which is a gas flowing through the circulation passage to yield condensed water, through heat exchange of the circulation gas with the ambient air, thereby separating, from the circulation gas, water vapor which has been condensed into condensed water through the heat exchange; and

a second condenser section provided in the circulation passage and adapted to condense water vapor contained in the circulation gas so as to yield condensed water, by means of cooling the circulation gas through utilization of latent heat of vaporization of condensed water which has been condensed in the first condenser section, thereby separating, from the circulation gas, the water vapor which has been condensed into condensed water through the utilization of latent heat of vaporization.

2. A working-gas-circulation-type engine according to claim 1, wherein:

the first condenser section is an upstream condenser section into which a pre-condensation exhaust gas, which is a gas exhausted from the combustion chamber in a state before undergoing condensation of water vapor and serving as the circulation gas, is introduced and which discharges, as a primary-condensed-water-separated gas, a gas obtained by separating, from the introduced pre-condensation exhaust gas, water vapor which has been condensed into condensed water through the heat exchange with the ambient air; and

the second condenser section is a downstream condenser section into which the primary-condensed-water-separated gas is introduced and which discharges, as a secondary-condensed-water-separated gas, a gas obtained by separating, from the primary-condensed-water-separated gas, water vapor which has been condensed into condensed water through the utilization of latent heat.

3. A working-gas-circulation-type engine according to claim 1 or 2, further comprising a water storage tank for storing condensed water which has been condensed in the first condenser section, wherein:

the second condenser section is configured so as to perform the latent-heat-utilizing cooling by means of using condensed water stored in the water storage tank.

4. A working-gas-circulation-type engine according to claim 1 or 2, wherein the second condenser section is configured so as to perform the cooling through additional utilization of latent heat of vaporization of condensed water which has been condensed in the second condenser section.

5. A working-gas-circulation-type engine according to claim 4, further comprising a water storage tank for storing condensed water which has been condensed in the first condenser section and condensed water which has been condensed in the second condenser section, wherein:

the second condenser section is configured so as to perform the latent-heat-utilizing cooling by means of using condensed water stored in the water storage tank.

6. A working-gas-circulation-type engine according to claim 4, further comprising:

a first water storage tank for storing condensed water which has been condensed in the first condenser section, and

a second water storage tank for storing condensed water which has been condensed in the second condenser section, wherein;

the second condenser section is configured so as to perform the latent-heat-utilizing cooling by means of using condensed water stored in the first water storage tank and condensed water stored in the second water storage tank.

7. A working-gas-circulation-type engine according to claim 1 or 2, further comprising gas-temperature-obtaining means for obtaining a temperature of the circulation gas which has passed through at least the first condenser section, wherein:

the second condenser section is configured such that usage of the condensed water whose latent heat of vaporization is utilized in the second condenser section is adjusted on the basis of the obtained temperature of the circulation gas.

8. A working-gas-circulation-type engine according to claim 7, wherein the gas-temperature-obtaining means is configured so as to obtain a temperature of the circulation gas which has passed through the first condenser section and has not yet been cooled in the second condenser section.

9. A working-gas-circulation-type engine according to claim 8, wherein the second condenser section is configured so as not to use the condensed water when the obtained temperature of the circulation gas is lower than a predetermined temperature.

10. A working-gas-circulation-type engine according to claim 1 or 2, further comprising water-vapor-content-obtaining means for obtaining a water vapor content of the circulation gas, wherein:

the second condenser section is configured such that usage of the condensed water whose latent heat of vaporization is utilized in the second condenser section is adjusted on the basis of the obtained water vapor content.

11. A working-gas-circulation-type engine according to claim 10, wherein the water-vapor-content-obtaining means is configured so as to obtain the water vapor content of the circulation gas which has passed through the first condenser section and has not yet been cooled in the second condenser section.

12. A working-gas-circulation-type engine according to claim 11, wherein the second condenser section is configured so as not to use the condensed water when the obtained water vapor content is lower than a predetermined water vapor content.