GB972720A - Improvements in and relating to heat energy storage systems - Google Patents

Abstract

972,720. Systems for heating by circulation of fluids; heating steam boilers by hot liquids or fluidized solids; removing furnace waste gases. BIRWELCO Ltd. June 13, 1963 [March 23, 1962], No. 7040/62. Headings F4A, F4U and F4X. A heat energy storage system includes hot and cold storage spaces 30 and 29 respectively, said storage spaces containing a heat storage medium (having a vapour pressure below atmospheric pressure at the maximum temperature achieved by the medium in the system) and being interconnected by first heat exchanger 13, 16 which is adapted to provide for the heating of the heat storage medium by a heat source as the medium passes through the heat exchanger 13, 16 from the cold to the hot storage. A second heat exchanger 40-42 is adapted to be cooled by a heat utilization means as the medium passes through it from the hot to the cold storage, and control means 35-38 are provided for automatically regulating the flow rate of the medium in dependence upon the rates of energy input by the heat source and/or energy withdrawal by the heat utilization means. A jacketed steel duct 13 has its inlet 14 vertically above the mouth of a converter 10 so that the products of combustion flow into duct 13, through its vertical and horizontal sections 27 and 15 respectively and into a convection section 16 of the first heat exchanger which includes a number of tubes 17 through which the products of combustion flow to an outlet 18. A centrifugal pump 32 pumps heat storage medium from the cold storage 29 to an inlet 22 of a chamber 20 enclosing the convection section 16. The medium flows upwardly around the pipes 17 in chamber 20 and enters the jacket 21 of duct 13 at the upper end of the convection section 16 which is closed at both ends by plates 19 and is provided with baffles 25 to regulate the flow of the medium. The lower end of the vertical section 27 of duct 13 is provided with a removable closure 28. The medium flows through the jacket 21 and into outlet connections 24 and 33 adjacent the converter 10 and the closure 28 respectively. The outlets 24 and 33 lead into a return pipe 34 through which the medium flows via control means 35-38 to the upper end of the hot storage 30. The control means, which comprises a valve 35 coupled to a temperatureresponsive element 37, automatically ensures that the temperature of the medium leaving duct 13 is constant. From the lower end of the hot storage 30, a centrifugal pump 38 pumps the heated medium via pipes 39, through a constant rate steam generator (comprising a superheater) 40, an evaporator 41, a water preheater 42 and back to the cold storage 29 A water stream, entering by inlet 44, flows by pipes 43 through the three heat exchangers 40-42 in the reverse order to that of the medium, and leaves as super-heated steam by outlet 45. The heat transfer medium can be fused mixtures of salts, fluidized finely divided solid, a refractory hydrocarbon oil, a molten metal or organic liquids such as diphenyl, diphenyl oxide or mixtures thereof. In a modification of the convection section, the tubes 17 may provide for the flow of the heat storage medium therethrough while the hot gases are directed over the exterior of the tubes.