A steam generator comprises: a pressure vessel; a gas inlet to the pressure vessel, arranged to receive hydrogen and oxygen under pressure; an ignition means within the pressure vessel, arranged to ignite hydrogen and oxygen received at the gas inlet; a water jacket in or on the pressure vessel; a water inlet arranged to receive water under pressure and feed it to the water jacket; a spray outlet within the pressure vessel; and a steam outlet for the outlet of steam from the pressure vessel. In use, water received at the water inlet passes along the water jacket to provide cooling of the pressure vessel and is output at the spray outlet to provide a water spray (and/or film) that mixes with the ignited hydrogen and oxygen to vaporize the water spray.

A supercritical hydrothermal combustion device comprises a main enclosure and a top cap. A partition is mounted in the main enclosure and divides the interior of the main enclosure into a main combustion space and a mixing space. The top cap is provided with a primary fuel inlet, an oxidant inlet and a secondary fuel inlet. A high-temperature ignition bar sleeve, having a high-temperature ignition bar arranged therein, is disposed in the top cap. A combustion sleeve, having a stable combustion space formed therein, is mounted at a bottom of the top cap, and has a top communicated with the high-temperature ignition bar sleeve and the oxidant inlet, as well as a bottom communicated with the main combustion space. The secondary fuel inlet and a secondary oxidant inlet are communicated with the main combustion space. Supercritical hydrothermal combustion is realized to generate a hybrid thermal fluid or treat organic wastes.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.

The invention relates to a tool for generating steam and combustion gases for. The tool is configured to enhance the longevity of its ignitor. The tool may have the ignitor recessed in but open to a wall of the tool's combustion chamber, to thereby protect the ignitor from flame impingement during use. The tool may alternately or in addition have passageways for inputs of air, fuel and/or water extending alongside and annularly around the ignitor, to thereby act to cool the ignitor during use.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydro-carbon fuel; a vessel containing feed-water; a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and high pressure combustion product and by-product directly into the feed-water of the vessel.

Liquid is flash evaporated in a series of cells along and surrounding an exhaust duct to generate a pressurized vapor where at least one of the surfaces is in communication with the source of heat sufficient to maintain the surface at a temperature such that the liquid injected into the chamber is substantially instantly converted to a superheated vapor with no liquid pooling within the chamber. The liquid is introduced by controlled injectors operating at a required rate. Each of the cells is periodically discharged by a pressure controlled relief valve and the vapor from the cells combined to form a continuous stream feeding a turbine or other energy conversion device. The outer wall of the cell is offset so that it contacts the inner wall at one point around the periphery. Heat transfer ribs and bars can be provided in the duct to provide increased heat transfer where necessary.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydro-carbon fuel; a vessel containing feed-water;

a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and pressure combustion product and by-product directly into the feed-water of the vessel.

An apparatus for rapidly evaporating liquid includes an exhaust flow channel having opposing openings including an upstream opening and a downstream opening. The channel defines an exhaust path proceeding from the upstream opening through the exhaust flow channel and through the downstream opening. Within the exhaust flow channel, a conduit path includes repeated passes transverse to the exhaust path. Attached to the exhaust flow channel proximate the downstream opening, a spray fixture is coupled to an exit port of the conduit. The spray fixture includes a divider to divide fluid from the exit port into multiple streams and an aimer to direct the multiple streams into the exhaust path.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.