The gas turbine may be operational so that its power ouptut can be selectively varied between a maximum and a minimum, and the burner means may be provided with fuel gas supply means by which the supply of fuel gas to the burner means can be selectively varied between zero and a maximum. The boiler may comprise a front plate, and the gas turbine may be mounted on said front plate. The boiler may be a shell boiler having a shell or casing which acts as a tank for water to be heated and contains said heating gases passage means. The gas turbine and the burner means each have a respective maximum heat energy output, and the maximum heat energy output of the burner means can be greater than the maximum heat energy output of the gas turbine. The boiler can be a steam boiler for raising steam, or the boiler may be simply a hot water boiler to produce hot water. This invention concerns a combined heat and power apparatus, and more particularly such an apparatus in which part of the heat needed is provided by hot exhaust gases emerging from a small gas turbine.Īccording to the invention a combined heat and power apparatus comprises a gas turbine driving electrical power generating means, a boiler comprising heating gases passage means to receive and convey hot heating gases therethrough whereby heat exchange takes place between said heating gases and water in the boiler to raise the temperature of said water, characterised in that the gas turbine has a power output which does not exceed 0.5 Megawatts, said gas turbine is mounted on said boiler at an inlet end of said passage means so that hot products of combustion constituting exhaust gases from the gas turbine are fed substantially directly from a gas turbine exhaust gas outlet end into said inlet end of said heating gases passage means so that heating gases comprise at least in part said exhaust gases when the gas turbine is operating, fuel gas burner means is disposed in said heating gases passage means at or adjacent to said inlet end thereof, and exhaust means is provided to create a pressure drop along said heating gases passage means towards an outlet end of said heating gases passage means to draw the heating gases towards the outlet end of the heating gases passage means. Apparatus as claimed in any one of Claims 1 to 12, characterised in that the boiler is a hot water boiler (2).

A combined heat and power apparatus comprising a gas turbine (34) driving electrical power generating means (60), a boiler (2) comprising heating gases passage means (10,16,22) to receive and convey hot heating gases therethrough whereby heat exchange takes place between said heating gases and water (6) in the boiler (2) to raise the temperature of said water, characterised in that the gas turbine (34) has a power output which does not exceed 0.5 Megawatts, said gas turbine (34) is mounted on said boiler (2) at an inlet end (32) to said heating gases passage means (10,16,22) so that hot products of combustion constituting exhaust gases from the gas turbine (34) are fed substantially directly from a gas turbine exhaust gas outlet end (40) into said inlet end (32) of said heating gases passage means (10,16,22) so that heating gases comprise at least in part said exhaust gases when the gas turbine (34) is operating, fuel gas burner means (68) is disposed in said heating gases passage means (10,16,22) at or adjacent to said inlet end (32) thereof, and exhaust means (26,72) is provided to create a pressure drop along said heating gases passage means (10,16,22) towards an outlet end (28) of said heating gases passage means (10,16,22) to draw the heating gases towards the outlet end (28) of the heating gases passage means.ġ5.

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