A combustible ice efficient combustion system comprises a combustible ice storage unit and a combustion unit, the front end of the furnace of the combustion unit is provided with a combustor, the rear end of the furnace of the combustion unit is connected with a flue gas main pipe, the combustor is provided with a first fuel gas inlet, a second fuel gas inlet, a combustion-supporting gas inlet and a flue gas outlet, the first fuel gas inlet is provided with a combustion nozzle, the combustion nozzle is provided with a first gas inlet, a second gas inlet and a mixed gas outlet, the first gas inlet is connected with the combustible ice storage unit through a high-pressure natural gas pipeline, the second gas inlet is connected with an air source, and the mixed gas outlet is connected with the first fuel gas inlet of the combustor.

A hydrogen fuel delivery system (300) comprises a fuel line (312) having an inlet (315) and an outlet (316), a liquid fuel pump (307) configured to provide a flow of liquid hydrogen fuel from a hydrogen fuel storage tank (308) to the fuel line inlet (315), a heat exchanger (306) having first and second fluid paths (313, 314), the fuel line (312) passing through the first fluid path (313), a pre-heater line (317) having an inlet (318) connected to the fuel line (312) between the fuel line inlet (315) and the heat exchanger (306), the pre-heater line (317) comprising a first control valve (301) and a burner (305) between the pre-heater line inlet (318) and the heat exchanger (306), the pre-heater line (317) passing through the second fluid path (314) of the heat exchanger (306) towards a pre-heater line outlet (319), a second control valve (302) in the fuel line (312) between the heat exchanger (306) and the fuel line outlet (316), a first temperature sensor (321) configured to measure a first fuel temperature (T1) in the fuel line (312) between the heat exchanger (306) and the second control valve (302), and a control system (400) configured provide a first control signal (CV1) to control operation of the first control valve (301) dependent on an input target temperature (T1Target) compared to the first fuel temperature (T1) and on a measure of fuel flow (mbfuel) through the pre-heater line (317).