Hybrid Hot Hydrogen Balloon

The hybrid hot hydrogen balloon combines two lighter than air technologies: a hot air balloon and a hydrogen balloon.  A hot air balloon works by heating the air within the balloon.  The air expands which causes the mass of air contained within the balloon to be less than the surrounding air. The result is that the hot air balloon will rise.  A hydrogen balloon will rise without adding heat because hydrogen is lighter than air.  Now suppose the hydrogen is heated the way a hot air balloon is heated?  The efficiency of the hydrogen will increase. 

A hot air balloon burns a mixture of propane and air.  The idea behind the hybrid hot hydrogen balloon is that the balloon or envelope would contain hydrogen that was on fire; a very controlled fire. 

Many people think of hydrogen and the Hindenburg zeppelin that exploded in New Jersey in 1937.  Unfortunately, that terrible incident killed of the airship industry.  And, recent research has demonstrated that the silver coating (dope) on the skin of the aircraft was the primary fuel that caused the explosive fire that destroyed the Hindenburg.  The point being that hydrogen, while dangerous, is manageable when properly controlled.

The hybrid hot hydrogen balloon, at first appearance, looks like a rather standard helium balloon.  Upon closer inspection, however, one will observe several differences.  (A) The hybrid hot hydrogen balloon has a lightweight high temperature has a standard envelope.  (E) The hybrid hot hydrogen balloon has a lightweight high temperature capable wire that is suspended from the top of the balloon to the base.  This wire acts as a harness from which several devices are attached.  Attached to the wire at the bottom of the balloon, outside of the gas envelope, is a (F) microcontroller that manages all control functions for the system.  Also outside the balloon and attached to the harness wire is a (G) battery (or solar collector) to power the system.  A (F) small compressor is present to take outside air and feed it into the balloon through a (D) small tube.  The small tube enters the balloon and follows the harness wire to the center of the balloon where it attaches to an (C) igniter and (B) burner element. 

Once at altitude the controller turns on the compressor which feeds a stream of air into the center of the balloon.  An igniter causes the mixture of air and hydrogen to burn.  The controller regulates the flow of air and to keep the flame under control.

The flame will heat the remaining hydrogen gas and cause it to expand.  As it expands the balloon will increase it lift capabilities.

Some challenges come to mind such as (1) what would the net lift gain be from heating up the hydrogen?  (2) How much would the system weigh?  (3) How much hydrogen would have to be burned in order to provide a benefit and would that benefit be lost by decreasing the volume of the remaining gas?