A method for isolating substantially pure carbon dioxide from flue gas is provided. The method can include combusting carbon based fuel to form flue gas; cooling the flue gas to provide substantially dry flue gas; removing N.sub.2 from the dry flue gas to provide substantially N.sub.2 free flue gas CO.sub.2; and liquifying the substantially N.sub.2 free flue gas CO.sub.2 to form substantially pure carbon dioxide.

A method for isolating substantially pure carbon dioxide from flue gas is provided. The method can include combusting carbon based fuel to form flue gas; cooling the flue gas to provide substantially dry flue gas; removing N.sub.2 from the dry flue gas to provide substantially N.sub.2 free flue gas CO.sub.2; and liquifying the substantially N.sub.2 free flue gas CO.sub.2 to form substantially pure carbon dioxide.

A CO2 capture system includes an intake for CO2-rich exhaust gas to a compressor and one or more outlets for compressed, first CO2-rich gas to a manifold to a shell enclosing parts of a combustion chamber. The combustion chamber has burners to burn fuel and compressed air from a fuel line and an air supply pipe, to form a second, CO2 rich gas.

The wall in the combustion chamber has slits to let in the compressed CO2-rich gas to mix with and cool the other CO2-rich gas formed in the combustion chamber of a third CO2-rich exhaust gas. A heat exchanger operates under high pressure and heat exchanges the third, hot CO2-rich exhaust gas from the combustion chamber with returning CO2-poor exhaust gas from a CO2 extraction plant. The returned, heated CO2-poor exhaust gas is led back to an expander driving the compressor and the CO2 extraction plant.

A CO2 capture system includes an intake for CO2-rich exhaust gas to a compressor and one or more outlets for compressed, first CO2-rich gas to a manifold to a shell enclosing parts of a combustion chamber. The combustion chamber has burners to burn fuel and compressed air from a fuel line and an air supply pipe, to form a second, CO2 rich gas.

The wall in the combustion chamber has slits to let in the compressed CO2-rich gas to mix with and cool the other CO2-rich gas formed in the combustion chamber of a third CO2-rich exhaust gas. A heat exchanger operates under high pressure and heat exchanges the third, hot CO2-rich exhaust gas from the combustion chamber with returning CO2-poor exhaust gas from a CO2 extraction plant. The returned, heated CO2-poor exhaust gas is led back to an expander driving the compressor and the CO2 extraction plant.

Described herein is an apparatus and method for avoiding frost buildup on the air intake and or ice buildup on the ice condensing surfaces of the exhaust vent of a condensing appliance. The apparatus comprises a heat-conducting path that extends between the exhaust gas in the exhaust vent of the appliance, and the frost condensing surfaces at or near the air intake opening of the combustion air vent. The heat-conducting path has a first section in thermal contact with the exhaust gas and a second section in thermal contact with the frost condensing surfaces at or near the air intake. In one configuration, the heat-conducting path is a heat pipe. In one configuration the heat-conducting path is a heat exchanger assembly. The passive transfer of heat energy via the heat-conducting path, from the exhaust gas to the frost condensing surfaces at or near the air intake, avoids frost buildup.

Described herein is an apparatus and method for avoiding frost buildup on the air intake and or ice buildup on the ice condensing surfaces of the exhaust vent of a condensing appliance. The apparatus comprises a heat-conducting path that extends between the exhaust gas in the exhaust vent of the appliance, and the frost condensing surfaces at or near the air intake opening of the combustion air vent. The heat-conducting path has a first section in thermal contact with the exhaust gas and a second section in thermal contact with the frost condensing surfaces at or near the air intake. In one configuration, the heat-conducting path is a heat pipe. In one configuration the heat-conducting path is a heat exchanger assembly. The passive transfer of heat energy via the heat-conducting path, from the exhaust gas to the frost condensing surfaces at or near the air intake, avoids frost buildup.

Embodiments of the present disclosure include a system, method, and apparatus comprising a large scale direct steam generator operating on an oxidant of air or enriched air configured to generate steam and combustion exhaust constituents. An exhaust constituent separation system and an energy recovery system to reclaim energy and improve the efficiency of the thermodynamic cycle. An optional CO2 separation system and Non Condensable Gas injection system may be included.

Embodiments of the present disclosure include a system, method, and apparatus comprising a large scale direct steam generator operating on an oxidant of air or enriched air configured to generate steam and combustion exhaust constituents. An exhaust constituent separation system and an energy recovery system to reclaim energy and improve the efficiency of the thermodynamic cycle. An optional CO2 separation system and Non Condensable Gas injection system may be included.

A water heater includes a burner generating combustion gas, a heat exchanger heating water which flows through the inside, through heat exchange with combustion gas generated in the burner, a fan supplying air to the burner, and a housing storing these components. The water heater has a water entry portion in a top plate of the housing. A water supply pipe for supplying water to the inside of the heat exchanger is connected to the water entry portion. The water entry portion is arranged to be included, in a plane view, in at least one component constituting the heat exchanger and an exhaust path for combustion gas which has passed through the heat exchanger. The component is made of a material having corrosion resistance against drainage water resulting from condensation of combustion gas.

A water heater includes a burner generating combustion gas, a heat exchanger heating water which flows through the inside, through heat exchange with combustion gas generated in the burner, a fan supplying air to the burner, and a housing storing these components. The water heater has a water entry portion in a top plate of the housing. A water supply pipe for supplying water to the inside of the heat exchanger is connected to the water entry portion. The water entry portion is arranged to be included, in a plane view, in at least one component constituting the heat exchanger and an exhaust path for combustion gas which has passed through the heat exchanger. The component is made of a material having corrosion resistance against drainage water resulting from condensation of combustion gas.