A closed cycle plant for converting thermal power into electric power comprising:
- a closed circuit, inside which at least one working fluid according to a predetermined circulation direction circulates,
- at least one volumetric expander configured to receive at the inlet the working fluid at the gaseous state, said volumetric expander comprising:
- (i) at least one jacket having at least one inlet and one outlet respectively suitable for introducing and discharging the working fluid,
- (ii) an active element housed in said jacket and suitable for defining, in cooperation with said jacket, a variable volume expansion chamber,
- (iii) a main shaft associated to the active element and configured to rotatively move around an axis,
- (iv) at least one valve, active on the inlet and outlet of the jacket, and configured to selectively open and close said inlet and said outlet to allow at least one condition of introducing, one condition of expanding and one condition of discharging the working fluid from said expansion chamber,
- at least one electric energy generator connected to the main shaft,
- the valve comprising at least one regulation device configured to allow the variation of the at least one of the following parameters:
- (i) the duration of the introduction condition, and
- (ii) the maximum passage cross-section of the inlet,
- wherein the plant further comprises:
- at least one pump placed on the circuit and arranged to impose to the working fluid said predetermined circulation direction,
- at least one first heat exchanger active on the circuit and located downstream of the pump with respect to the working fluid circulation direction, said first heat exchanger being arranged for receiving at the inlet the working fluid and being configured to receive heat from a hot source and allow the heating of the working fluid until it is caused the passage from the liquid state to the gaseous one,
- said volumetric expander being connected downstream of the first heat exchanger, with respect to the working fluid circulation direction inside the circuit, and being configured to receive at the inlet the working fluid at the gaseous state generated in the first exchanger,
- wherein the regulation device comprises at least one mask movable relatively to the inlet to allow the variation of the maximum cross-section and determine a regulation of the volumetric flow rate of the working fluid entering the expansion chamber during the introduction condition,
- wherein said regulation device comprises:
- (i) at least one first sensor active on the circuit, and configured to generate a first detection signal regarding the at least one pressure parameter of the working fluid at the gaseous state, entering the volumetric expander,
- (ii) at least one second sensor active on the circuit and configured to generate a second detection signal regarding at least one pressure parameter of the working fluid at the liquid state upstream of the pump, and
- (iii) a control unit connected to the first and second sensors, and configured to:
- (a) receive from the first and second sensors the respective first and second detection signals;
- (b) process the signal received from the first and second sensors for determining the pressure of the working fluid respectively entering the volumetric expander and upstream of the pump;
- and
- (c) position the mask relatively to the inlet, as a function of at least one the values of said working fluid pressures.