Reciprocating external-combustion engine and method of operating the same

Claim 2

A reciprocating external combustion engine wherein energy is transferred to a working gas from a heated liquid heat-transfer medium, which comprises a cylinder, a piston within the cylinder and reciprocatable therein, a working end space being defined by the cylinder and piston; a heat exchanger for heating the heat-transfer medium externally of the cylinder under a pressure such as to maintain the medium in the liquid state, the heat exchanger having an inlet for receiving heat-transfer medium and an outlet for delivering heated liquid heat-. transfer medium; induction means connected to-the cylinder for inducting gas into the working end space; an injector connected to the outlet of the heat exchanger and arranged to inject heated liquid medium into the gas before expansion of the gas in the working end space; and an outlet from the cylinder for exhausting heat transfer medium and working gas from the working end space near the end of an expansion stroke of the piston.

Claim 3

An engine according to claim 1 wherein the injector is mounted on the cylinder so as to inject heated liquid medium directly into the working gas in the working end space.

Claim 4

An engine according to claim 1 which further comprises a mixing chamber having an inlet for working gas, the injector being mounted in the chamber for injecting heated liquid medium into the gas, prior to the wet gas being inducted into the working end space.

Claim 5

. An engine according to claim 1, wherein the gas is compressed before the heated liquid medium is injected into the gas.

Claim 6

An engine according to claim 4, wherein the gas is compressed by means of a rotary compressor.

Claim 7

An engine according to claim 4, wherein the cylinder is a double-acting cylinder defining on one side of the piston the working end space and defining on the other side of the piston a compressor end space, the compressor end space having an inlet for working gas and an outlet.

Claim 8

An engine according to claim 4 arranged to operate according to a four-stroke cycle, which includes an induction stroke and a compression stroke for the working gas.

Claim 9

An engine according to claim 1 wherein the injector is an atomizing injector, which atomizes the injected liquid medium so as to facilitate heat transfer to the gas.

Claim 10

An engine according to claim 1, wherein the heat exchanger comprises at least one tube for containing the heat-transfer medium and a fuel burner for heating the medium in said at least one tube under a pressure such as to maintain the medium in the liquid phase.

Claim 11

An engine according to claim 1, which further comprises a trap connected to the outlet from the cylinder for recovering. liquid heat-transfer medium from the wet exhaust gas.

Claim 12

An engine according to claim 1-wherein recycle means are provided for recycling the exhausted heat-transfer medium to the heat exchanger.

Claim 13

An engine according to claim 11 wherein the recycle means comprises a spray chamber having an inlet for heat transfer medium and an inlet for flue gases connected to the heat exchanger, the chamber having a snray for spraying liquid heat-transfer medium through the flue gas from the burner so as to preheat the liquid medium, the chamber further having an outlet connected for feeding heat-transfer medium to the heat exchanger, and an outlet for flue gas.

Claim 14

An engine according to claim 1 which further comprises speed control means for controlling the rate of working of the engine by controlling the amount of liquid heat-transfer medium injected.

Claim 15

An engine according to claim 13 wherein the speed control is a variable displacement pump.

Claim 16

15, An engine according to claim 1 which further comprises speed control means for controlling the rate of working of the engine by controlling the temperature of the injected heat-transfer medium.

Claim 17

16, A reciprocating external combustion engine wherein heat energy is transferred to air acting as a working gas by means of pressurized liquid water at a temperature greater than the boiling point of water at atmospheric pressure, which comprises a cylinder, a piston.within the cylinder and reciprocatable therein, a working end space being defined by the cylinder and piston; a heat exchanger for heating the liquid water externally of the working space to a temperature above the boiling point of water at atmospheric pressure, the heat exchanger having 1) an inlet for receiving liquid water and an outlet for delivering heated water, 2) at least one tube for containing said liquid water, and 3) a fuel-burner disposed for heating the liquid water in said at least one tube; pressurizing means connected to said at least one tube of the heat exchanger for maintaining said heated water in the liquid state; induction means connected to the cylinder for inducting air into the working end space near the beginning of a compression stroke of the piston; an injector mounted on said cylinder and connected to the outlet of the heat exchanger for receiving heated pressurized liquid water; control means for controlling the injector to inject said heated pressurized liquid water into the working end space near the end of the compression stroke of the piston; and . an outlet from the cylinder for exhausting cooled water and air from the working end space near the end"of an expansion stroke of the piston, the majority of said cooled water being exhausted in the liquid state.

Claim 18

16, A reciprocating external combustion engine wherein heat energy is transferred to air acting as a working gas by means of pressurized liquid water at a temperature greater than the boiling point of water at atmospheric pressure, which comprises a cylinder, a piston.within the cylinder and reciprocatable therein, a working end space being defined by the cylinder and piston; a heat exchanger for heating the liquid water externally of the working space to a temperature above the boiling point of water at atmospheric pressure, the heat exchanger having 1) an inlet for receiving liquid water and an outlet for delivering heated water, 2) at least one tube for containing said liquid water, and 3) a fuel-burner disposed for heating the liquid water in said at least one tube; pressurizing means connected to said at least one tube of the heat exchanger for maintaining said heated water in the liquid state; induction means connected to the cylinder for inducting air into the working end space near the beginning of a compression stroke of the piston; an injector mounted on said cylinder and connected to the outlet of the heat exchanger for receiving heated pressurized liquid water; control means for controlling the injector to inject said heated pressurized liquid water into the working end space near the end of the compression stroke of the piston; and . an outlet from the cylinder for exhausting cooled water and air from the working end space near the end"of an expansion stroke of the piston, the majority of said cooled water being exhausted in the liquid state.

Claim 19

A reciprocating external combustion engine wherein energy is transferred to a working gas from a heated liquid heat-transfer medium, which comprises a cylinder, a piston within the cylinder and reciprocatable therein, and a working end space on at least one end of the piston; means for heating the heat-transfer medium externally of the cylinder under a pressure such as to maintain the medium in the liquid state; induction means connected to the cylinder for inducting gas into the working end space; an injector arranged to inject heated liquid medium into the gas before expansion of the gas in the working end space; and an outlet from the cylinder for exhausting heat transfer medium and working gas from the working end space.

Claim 20

A reciprocating external combustion engine wherein energy is transferred to a working gas from a heated liquid heat-transfer medium, which comprises a cylinder, a piston within the cylinder and reciprocatable therein, and a working end space on at least one end of the piston; means for heating the heat-transfer medium externally of the cylinder under a pressure such as to maintain the medium in the liquid state; induction means connected to the cylinder for inducting gas into the working end space; an injector arranged to inject heated liquid medium into the gas before expansion of the gas in the working end space; and an outlet from the cylinder for exhausting heat transfer medium and working gas from the working end space.

Claim 23

A method according to claim 18 wherein the heat transfer medium is selected from the group consisting of water, oil, sodium, mercury and mixtures thereof.

Claim 24

A method according to claim 18 or 19 carried out under such conditions of temperature and pressure that at least part of the injected liquid medium vaporizes on injection.

Claim 26

22, A kit of parts for converting an internal combustion engine to a reciprocating external combustion engine according to claim 1, which comprises means for heating liquid under pressure; an insulated cylinder and piston, the cylinder having an inlet for gas and an outlet for wet exhaust gas; a compressor for inducting gas into the cylinder; a pressure pump for feeding liquid to the heat exchanger; an injector for injecting liquid directly or indirectly under pressure into the cylinder; a metering device for controlling the amount of liquid injected; and a separating chamber for receiving wet exhaust gas and separating dry saturated vapor and gas from liquid.

Claim 27

A kit of parts for converting an internal combustion engine to a reciprocating external combustion engine according to claim 1, which comprises

Claim 28

. a heat exchanger including a fuel-air burner for heating water under pressure; an insulated cylinder and piston, the cylinder having an inlet for gas and an outlet for wet exhaust gas; a compressor for inducting gas into the cylinder; a pressure pump for feeding water to the heat exchanger; an injector for injecting liquid water directly or indirectly under pressure into the cylinder; a metering device for controlling the amount of water injected; and a separating chamber for receiving wet exhaust gas and separating dry saturated vapor and gas from liquid.

Claim 29

. a heat exchanger including a fuel-air burner for heating water under pressure; an insulated cylinder and piston, the cylinder having an inlet for gas and an outlet for wet exhaust gas; a compressor for inducting gas into the cylinder; a pressure pump for feeding water to the heat exchanger; an injector for injecting liquid water directly or indirectly under pressure into the cylinder; a metering device for controlling the amount of water injected; and a separating chamber for receiving wet exhaust gas and separating dry saturated vapor and gas from liquid.