Abstract: A boiler unit comprises an enclosure including: a first circuit of a first fluid heat exchange medium, the first circuit having a heating device to heat the first medium, a boost heat exchanger, a valve and a first manifold; a second circuit of a second heating system fluid heat exchange medium, the second circuit having a flow and return port of the boiler unit, a second manifold and said boost heat exchanger for exchange of heat between said first and second heat exchanger media when said valve is open; a space in the enclosure receiving an auxiliary unit to be driven substantially exclusively by said first fluid heat exchange medium; and a boiler control unit to control operation of the heating device according to heat demand of the heating device and otherwise irrespective of the auxiliary unit when connected; and an organic rankine cycle (ORC) unit comprising: a third fluid heat exchange medium circuit, the circuit including a condenser adapted for connection to said second manifold to provide heat to sa

Abstract: An ORC heat engine including a working fluid circuit having an evaporator for heating and evaporating a working fluid, a condenser for cooling and condensing the working fluid, and a positive displacement expander-generator having an inlet in fluid communication with the evaporator and an outlet in fluid communication with the condenser. The ORC heat engine further includes a control system coupled to the positive displacement expander-generator having a switch and driving means, the switch being switchable between a first state and a second state, wherein in the first state the switch is coupled to the driving means, and the positive displacement expander-generator is drivable by the driving means, and in the second state the switch is not coupled to the driving means or the driving means is switched off, and the positive displacement expander-generator is not drivable by the driving means.

Abstract: A closed cycle heat transfer device comprising a boiler (10) and a condenser (13), the condenser being used to recover useful heat by latent heat evaporation. A circuit defined by the boiler (10), condenser (13) and ducts (12, 15) is to be liquid-filled at a pressure just above atmospheric pressure. An expansion device (16) maintains the working pressure in the circuit but will receive excess condensate in a liquid phase to compensate for expansion of the working fluid vapor which passes from the boiler (10) to the condenser (13). The expansion chamber contains a movable or flexible member which, when working liquid is received in the chamber, is displaced to compress a gas in the chamber.

Abstract: A closed cycle heat transfer device comprising a boiler (10) and a condenser (13), the condenser being used to recover useful heat by latent heat evaporation. A circuit defined by the boiler (10), condenser (13) and ducts (12, 15) is to be liquid-filled at a pressure just above atmospheric pressure. An expansion device (16) maintains the working pressure in the circuit but will receive excess condensate in a liquid phase to compensate for expansion of the working fluid vapour which passes from the boiler (10) to the condenser (13). The expansion chamber contains a movable or flexible member which, when working liquid is received in the chamber, is displaced to compress a gas in the chamber.