Modular power generating system

• US 20080018109A1
• Filed: 07/18/2007
• Published: 01/24/2008
• Est. Priority Date: 07/21/2006
• Status: Active Grant

• Current Assignee: C.R.F. Societa Consortile Per Azioni
• Original Assignee: C.R.F. Societa Consortile Per Azioni
• Inventors: Campanile, Pasquale, Anzioso, Franco
• Granted Patent: US 7,629,701 B2
• Time in Patent Office: Days
• US Class Current: 290/2
• CPC Class Codes: F02C 6/18 using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

The system comprises a main cogeneration module which can be supplied with a flow of fuel for a combustion process and is able to generate electrical energy and thermal energy in the form of a flow of at least one first hot fluid, preferably water. The main module has an electrical output terminal or node which can be directly connected to electrical user appliances and can be connected in parallel to an external electric power generating and supply network via a controlled switching device. The system comprises moreover

a bottoming cycle recovery cogeneration apparatus able to recover, and partially convert into useful work, thermal energy from the products of the combustion process;

an auxiliary generation module which can be supplied with thermal energy produced by the main module and is able to provide thermal energy at a lower temperature in the form of a flow of at least one second chilled fluid; and

management and control devices preset to manage in a predetermined manner operation of the main module and the auxiliary module.

Claims

1. Modular power generating system, comprising

a main cogeneration module which can be supplied with a flow of fuel for a combustion process and is able to generate electrical energy and thermal energy in the form of a flow of at least one first hot fluid, preferably water;

the main module having an electrical output terminal or node which can be directly connected to electrical user appliances and can be connected in parallel to an external electric power generating and supply network via a controlled switching device;

a bottoming cycle recovery cogeneration cycle apparatus associated with the main cogeneration module, for recovering, and partially converting into useful work, thermal energy from the products of said combustion process;

an auxiliary generation module which can be supplied with thermal energy produced by the main module or by the recovery cogeneration apparatus and is able to provide thermal energy at a lower temperature in the form of a flow of at least one second chilled fluid; and

management and control means preset to manage in a predetermined manner operation of the main module, the recovery cogeneration apparatus and the auxiliary module;

the main cogeneration module comprising;

an electric power generating unit including an internal combustion engine supplied with said fuel and coupled to an alternating-current rotary electric generator, preferably of the three-phase type;

an electronic converter unit including an ac/dc converter connected to the output of said electric generator, a dc/ac converter, preferably with a three-phase output, connected to the output of the ac/dc converter via a dc link and to the electric output terminal or node of the main module, and an electric power storage module coupled to the abovementioned dc link, directly or via a bidirectional dc/dc converter, in such a way that said dc/dc converter is able to allow a flow of electric power from the storage module to the dc link and vice versa; and

a heat exchange module coupled to the internal combustion engine and able to recover part of the heat generated, during operation, by this engine, transferring it to said at least one first fluid, said heat exchange module having electrovalve control means able to allow variation in the degree of recovery of the heat generated by the engine;

the auxiliary generation module comprising a heat pump intended to receive a flow of a hot fluid from said heat exchange module or from the engine or from said recovery cogeneration apparatus and able to provide at its output a flow of said at least one second fluid at a relatively lower temperature;

said management and control means being preset to;

regulate the electric power generated by the main module, controlling the speed of rotation and the fuel injection of the internal combustion engine in such a way that the latter operates with a predetermined efficiency;

regulate the ratio between the electric power and the thermal power generated by the main module, controlling the speed of rotation and the torque supplied by the internal combustion engine and driving in a predetermined manner the abovementioned electrovalve control means;

control in a predefined manner operation of the recovery cogeneration apparatus;

manage in a predetermined manner operation of the main module disconnected or connected to said network and the automatic transition between said operating modes;

regulate, when the main module is connected to the network, the output voltage and the power factor of said main module and compensate for any deviations from the sinusoidal waveform of the current supplied to said electrical user appliances; and

detect a condition where there is an interruption in the service of said electrical network and ensure the continuity of electrical power supply to at least some of said user appliances, using electric power supplied by said storage module, for a minimum period of time sufficient to ensure operation of said electric generator unit.

2. Modular power generating system according to claim 1, in which the electrical output terminal or node can be connected to the external network by means of switching means including an interruption system of the solid-state and/or electromechanical type.

3. Modular power generating system according to claim 1, in which the recovery apparatus comprises a fluid circuit including

a steam generator able to receive a flow of liquid, in particular water, from a circulating pump and convert this flow into a flow of steam using the heat of the exhaust gases produced by the engine of the main module;

a steam engine connected to the output of the steam generator, and

a condensation means connected between the steam engine and the input of the circulating pump.

4. Modular power generating system according to claim 3, in which the steam engine is coupled to an additional alternating-current rotary electric generator, preferably of the three-phase type.

5. Modular power generating system according to claim 2, in which said additional electric generator is connected to said electrical output terminal or node.

6. Modular power generating system according to claim 3, in which the recovery cogeneration apparatus also comprises a burner which can be coupled to the steam generator.

7. Modular power generating system according to claim 3, in which the recovery cogeneration apparatus also comprises a steam buffer connected between the steam generator and the steam engine.

8. Modular power generating system according to claim 4, in which an additional ac/dc converter is coupled to the output of said additional electric generator.

9. Modular power generating system according to claim 7, in which the output of said additional ac/dc converter associated with said additional electric generator is coupled to the abovementioned dc link.

10. Modular power generating system according to claim 3, in which said condenser means is able to perform condensation of the fluid from the steam engine by means of heat exchange with a flow of liquid or gas from outside directed to the abovementioned heat exchange module.

11. Modular power generating system according to claim 3, in which the steam engine includes a turbine.

12. Modular power generating system according to claim 3, in which the recovery cogeneration apparatus operates essentially using a Rankine thermodynamic cycle.

13. Modular power generating system according to claim 1, in which a control unit including a digital signal processor is associated with the electric generator unit, said control unit being connected to a control input of the abovementioned switching device, to the ac/dc converter and dc/ac converter of the converter unit, to the abovementioned dc/dc converter and an electronic control unit of the internal combustion engine and also to means for detecting the voltage and the current in the network upstream of said switching device.

14. Modular power generating system according to claim 3, in which said control unit is also preset to control in a predefined manner the pump and the steam engine of the recovery cogeneration apparatus.

15. Modular power generating system according to claim 6, in which the control unit is also preset to control in a predetermined manner the abovementioned burner of the recovery cogeneration apparatus.

16. Modular power generating system according to claim 8, in which the control unit is also preset to drive in a predetermined manner the abovementioned additional ac/dc converter.

17. Modular power generating system according to claim 1, in which said dc/dc converter is able to perform recharging of the electric power storage module and is arranged so that its side connected to the dc link has a higher voltage than its side connected to the electric power storage module.

18. Modular power generating system according to claim 1, in which the electric power storage module is connected to the dc link in such a way that it may be charged by the ac/dc converter and/or by the dc/ac converter.

19. Modular power generating system according to claim 1, in which the output of at least one additional direct-current voltage generator, such as a photovoltaic generator or a fuel cell generator, is connected to said dc link.

20. Modular power generating system according to claim 1, in which said auxiliary generation module comprises a thermally activated heat pump, in particular of the chemical type with a drying liquid.

21. Modular power generating system according to claim 20, in which said auxiliary generation module also comprises heat storage means.

22. Modular power generating system according to claim 1, in which said management and control means are preset to drive said converters in such a way that said main cogeneration module is able to supply reactive power both of the capacitive type and of the inductive type, said reactive power being coupled to the network by means of the abovementioned switching device.