Heat recovery

There is suggested a method for the recovery of heat from products of combustion (flue gases) of a fuel, at a higher temperature to another fluid at a relatively lower temperature comprising the following steps: (i) increasing the velocity of the hot flue gases, from combustion of a fuel, multifold than hitherto possible, by means of feeding compressed air powered by a turbo charger/turbo compressor (6a) to the fuel, in the burning stage; (ii) subjecting the fuel cum high pressure air to a step of burning in an enclosure (17); (iii) adjusting the fuel burning rate vis-à-vis the quantity/pressure of air to achieve steady state burning condition; (iv) producing and maintaining a steady flame of dimensions (length diameter) considerably smaller than hitherto possible in said burning enclosure (17); (v) recovering and indirectly transferring a small part of the heat of combustion to a relatively colder external fluid held surrounding the said burning enclosure; (vi) passing the products of combustion through a first heat exchanger (11); (vii) recovering and indirectly transferring a major part of the heat of the products of combustion, predominantly by convective heat transfer in said first heat exchanger (11), to the external fluid, which is the same said fluid which surrounds the burner enclosure (17) or is a different fluid altogether; (viii) passing the partly heat depleted flue gases coming out of said first heat exchanger through a turbine (6b) of turbo charger/turbo compressor and converting partial thermal energy content of flue gases into mechanical energy in turbine of turbo charger/turbo compressor which in turn is utilized to compress fresh air to high pressure in compressor of turbo charger/turbo compressor (6a) mounted on the same shaft of the turbine (6b) of turbo compressor to be used as combustion air in the burner in applications specified thereof and then through a second heat exchanger (12); (ix) recovering and indirectly transferring further heat from and said partly heat depleted flue gases in the second heat exchanger (12) to the external fluid which is the same said fluid which surrounds the burner enclosure (17) and first heat exchanger (11) or is a different fluid altogether; (x) recovering substantially all the remaining heat through said second heat exchanger also through convective heat transfer and finally; (xi) allowing all the heat depleted flue gases to pass to an exhaust/stack (16). A suitable system is also disclosed.