Power plants

A power plant comprising combustion means for generating heat for use in a power plant with at least two hot gas engines, such engine comprising:

• first and second working fluid spaces, regenerative heat exchange means in communication with said first and second working fluid spaces, reciprocating means for varying the volume to said working fluid spaces, heating means for heating working fluid in said first working fluid space, cooling means adjacent to said second working fluid space, a source of cooling fluid and first conduit means connecting said source of cooling fluid and said cooling means to convey cooling fluid from said source of cooling fluid to said cooling means to cool working fluid in said second working fluid space;
• means for conveying the products of combustion from said combustion means to the heating means of said two hot gas engines to heat working fluid in said first working fluid space of the respective engines;
• second conduit means in communication with cooling means of said one hot gas engine and the combustion means to convey cooling fluid from said cooling means of said one hot gas engine to the combustion means combustion therein, the cooling means of said second hot gas engine being independent of the combustion means, a further source of cooling fluid, third conduit means in communication with said further source of cooling fluid to said combustion means for combustion therein, and heat exchange means for transferring heat from cooling fluid fed to said independent cooling means to the cooling fluid fed from said further source of cooling fluid to said combustion means wherein, in operation of the plant, said cooling fluid fed from said further source of cooling fluid to said combustion means has had its physical state changed by heat which it absorbed in the cooling means of said one hot gas engine.