A dual fuel burner system includes a fuel burner housing and a main fuel supply conduit within the fuel burner housing. A main fuel nozzle is positioned proximate to a downstream end of the fuel burner housing and is in fluid communication with the main fuel supply conduit. The main fuel supply conduit is configured to provide 100% of the heat input requirement of the dual fuel burner system. A secondary fuel supply conduit is within the fuel burner housing. The secondary fuel supply conduit is configured to provide 100% of the heat input requirement of the dual fuel burner system. An air circuit is in fluid communication with an outlet of the main fuel nozzle. A direct spark ignitor is positioned proximate to the outlet of the main fuel nozzle.

A cartridge tip includes a main body having an outer annular wall and an inner core each extending between a respective upstream end and a respective downstream end. The inner core is radially spaced apart from the outer annular wall such that an annular air passage is defined at least partially between the outer annular wall and the inner core. A pilot fuel circuit extends between a pilot inlet defined in the upstream end of the inner core and a pilot outlet defined in a downstream end of the inner core. The pilot fuel circuit extends at least partially along an axial centerline of the cartridge tip. A main fuel circuit extends between a main inlet in the upstream end of the inner core and a plurality of main outlets circumferentially spaced apart from one another and disposed upstream from the from the pilot outlet.

Emissions of NO.sub.X and/or CO are reduced at the stack by systems and methods wherein a primary fuel is thoroughly mixed with a specific range of excess combustion air. The primary fuel-air mixture is then discharged and anchored within a combustion chamber of a burner. Further, the systems and methods provide for dynamically controlling NO.sub.X content in emissions from a furnace by adjusting the flow of primary fuel and of a secondary stage fuel, and in some cases controlling the amount or placement of combustion air into the furnace.

Emissions of NO.sub.X and/or CO are reduced at the stack by systems and methods wherein a primary fuel is thoroughly mixed with a specific range of excess combustion air. The primary fuel-air mixture is then discharged and anchored within a combustion chamber of a burner. Further, the systems and methods provide for dynamically controlling NO.sub.X content in emissions from a furnace by adjusting the flow of primary fuel and of a secondary stage fuel, and in some cases controlling the amount or placement of combustion air into the furnace.

A heating apparatus, in particular for recreational vehicles like campers or caravans, comprises a heating unit and two separate heat exchanging units, which are coupled to the heating unit in parallel with each other. The heating unit comprises one burner for each heat exchanging unit and one common single combustion air fan unit. The single combustion air fan unit is configured to supply both burners with combustion air, and the burners are configured to burn fuel gas or liquid further supplied to each of the burners together with the combustion air received from the single combustion air fan unit to get hot exhaust gasses. The heat exchanging units are configured to receive the exhaust gasses from the burners, and to transfer heat from the exhaust gasses to fluids to be heated, provided within the heat exchanging units. Furthermore, the present invention refers to a recreational vehicle with such a heating apparatus and methods for heating two distinct fluids with the above heating apparatus.

A heating apparatus, in particular for recreational vehicles like campers or caravans, comprises a heating unit and two separate heat exchanging units, which are coupled to the heating unit in parallel with each other. The heating unit comprises one burner for each heat exchanging unit, and at least one combustion air fan unit configured to supply the burners with combustion air. The burners are configured to burn fuel gas or liquid further supplied to each of the burners together with the combustion air received from the combustion air fan unit to get hot exhaust gasses. The heat exchanging units and are configured to receive the exhaust gasses from the burners, and to transfer heat from the exhaust gasses to fluids to be heated, provided within the heat exchanging units. The heat exchanging units are positioned in parallel with each other side by side on one side of the heating unit. Furthermore, the present invention refers to a recreational vehicle with such a heating apparatus.

An engine can utilize a combustor to combust fuel to drive the engine. A fuel nozzle assembly can supply fuel to the combustor for combustion or ignition of the fuel. The fuel nozzle assembly can include a swirler and a fuel nozzle to supply a mixture of fuel and air for combustion. The fuel nozzle assembly can be configured to increase lateral provision of fuels to reduce flame scrubbing on combustor liners for the combustor.

A heating apparatus, in particular for recreational vehicles like campers or caravans, comprises a heating unit and at least one heat exchanging unit coupled to the heating unit. The heating unit comprises at least one burner and at least one combustion air fan unit. The combustion air fan unit is configured to supply the burner with combustion air. The burneris configured to burn fuel gas or liquid further supplied to the burnertogether with the combustion air received from the combustion air fan unitto get hot exhaust gasses. The heat exchanging unitis configured to receive the exhaust gasses from the burnerand to transfer heat from the exhaust gasses to a fluid to be heated, provided within the heat exchanging unit. The burnercomprises at least two nozzles configured to supply fuel gas or liquid to a combustion area in which the fuel gas or liquid is to be burned with the combustion air. Each of the nozzles is coupled to its own fuel gas or liquid valve to control the fuel gas or liquid supply for the nozzles independently of each other. Furthermore, the present invention refers to a recreational vehicle with such a heating apparatusand methods for starting and controlling the above heating apparatus.

A dual fuel heating source can have a burner and a nozzle. The heating source can be configured to use one of two different fuels flowing at different pressures. The nozzle can have a body, the body defining an outlet opening, an inlet, and an inner chamber. The nozzle can be configured for the first fuel in a first position of said nozzle, and can be configured for a second fuel in a second position.

In various embodiments, a fuel injector may comprise a fuel nozzle and a pilot stage. The fuel nozzle may define a main fuel channel, a secondary fuel channel, a simplex fuel channel and a heat shield area. The main fuel channel may be disposed about at least a portion of the simplex fuel channel. The secondary fuel channel may be disposed about at least a portion of the simplex fuel channel. The heat shield area may be configured to separate and protect the fuel channels from a heat load to prevent fuel coking. The pilot stage may be operatively coupled to the fuel nozzle and may be configured to receive fuel from the secondary fuel channel or the simplex fuel channel. The main stage may be operatively coupled to the fuel nozzle. The main stage may be configured to receive fuel from the main fuel channel.